A New Palette

May 2, 2017 by grahamrob in Deep Sky Objects, Equipment, Galaxy, Imaging and tagged Camera | 2 Comments

Colour

It still remains early days with the new ZWO 1600MM-Cool camera but the initial signs using the narrowband filters have been very promising and frankly good fun. I’ve been surprised at the benefits gained using these filters and especially the new and exciting possibilities it introduces to imaging. But there’s more.

When first using a digital camera for astrophotography it came as a surprise to discover that the colours come from an RGB Bayer Matrix placed in front of the sensor. The so-called One Shot Colour camera or OSC, provided me with many decent images and when I recently started to think about getting a better camera another OSC seemed the way to go. Their major benefit is that you are able to just take, as it says, one shot – or multiple colour shots for stacking. Of course there’s still much to learn when starting out but the process is relatively simple and a decent set of subs and calibration frames can be obtained in a few hours or less; subsequent processing is also straightforward with one set of subs and no more than three sets of calibration frames.

Notwithstanding, when looking at more specialized OSC cameras, it soon became clear that the benefits of moving from DSLR were limited. Another surprise with astrophotography is that the best images are obtained using a mono camera, in combination with colour and if required narrowband filters. Hitherto, this has meant precise guiding in order to obtain long exposures using a very expensive CCD camera. However, last year everything changed with the introduction of completely new technology in the form of a cooled CMOS camera, which I and the astrophotography community are currently getting to grips with – the aforementioned ZWO ASI1600MM-Cool.

Whilst more complex to use than a DSLR, this camera seems to be something of a game changer for astrophotographers in that: (a) it has a larger more sensitive sensor than a CCD camera, (b) it’s cheaper (though not cheap), (c) because of its sensitivity imaging requires only relatively short exposures, thus reducing the need for ultra-precise guiding as it gathers light more quickly than a conventional camera. It was the latter feature that convinced me to go ahead with the camera and it is already clear this was not a mistake.

I often complain about the excessive cloud cover we suffer here at Fairvale Observatory, which can often prohibit imaging for weeks or even months on-end. The advantage of imaging quickly when the clouds do eventually part is therefore a major factor for me. If the camera has one problem it’s probably the vast quantity of data generated, putting huge demand on computer memory and processing power – but it’s worth it.

LRGB

LRGB imaging is the main format used by most advanced astrophtographers, after all the resulting colours and detail achieved can be spectacular and it was now time for me to give it a try. I was astonished to learn that some 80% of the detail in an image is in the luminance and only 20% colour, so the advantage of LRGB imaging becomes immediately apparent. I also purchased the ZWO x8 EFW and matching 31mm filters with the camera and initially had some problems getting it to work. However, once sorted it has been a pleasure to use and makes image sequencing with different filters a piece of cake.

At the moment I’m using Astro Photography Tool (APT) for capture and apart from my own lack of LRGB imaging experience and some misunderstandings of the software, it works very well. A full LRGB sequence is easy to set-up beforehand and after that the imaging automatically looks after itself! I carry out most of the calibration frames manually but this too is generally quite easy; I did struggle at first with the flats, which is a quite different method compared to a DSLR but once I got the hang of the APT Flats Aid – courtesy of the APT Forum members – all was OK.

Initial flats show a halo effect

Similar halo apparent in Ha image

Notwithstanding, at first I was concerned by large concentric light and dark halos in the flats. I have long used the combination of a flowerpot, LED and T-shirt for taking flats, which has always worked well. I therefore expected the flats from the new camera using APT would not be a problem. However, as mentioned taking flats with this camera is a whole new ball game which has taken some time to master, or at least learn.

The flower pot flats set-up has always worked well before.

Unlike the DSLR, which just requires changing to the AV mode, it is necessary to calculate an exact exposure – to five decimal places – using a mid-range ADU setting of between 20,000 and 25,000 for each different LRGB filter. Sounds awful and it does generate a lot of frames but now I’ve got the hang of the Flats Aid it is much easier and very effective; on average I have so far found the required exposures vary from 0.00145 sec to 0.00792 sec. I did discover some minor light leakage in the optical train when testing the flats taken in daylight but by doubling up the T-shirt material and adopting a more careful set-up of the flower pot directly in front of the telescope object lens, the halos now seem to have disappeared.

The other new ‘toy’ with this camera is cooling. Despite the camera’s low noise and high sensitivity, like all digital cameras there is an inevitable amount of unwanted signal and currents created by the sensor. Apart from applying calibration frames, this problem can be significantly reduced by cooling the sensor when imaging. APT also has cooling and warming aid controls to avoid thermal shock but at first I struggled to get these working – turns out I forgot to plug the power lead in! After that it has worked like a dream and I am now routinely imaging at -30^oC. The one drawback is that cooling down and warming up adds another 10 or 15 minutes to the set-up and take-down times, which can be annoying at 2.00 a.m. when you want to get to bed!

Unfortunately, now I have this camera working suitable imaging targets are in short supply for the moment. At first I was able to carry out some narrowband imaging of the remaining late winter nebulae just before they disappeared for the season but I must now wait for a few months until later in the year for similar objects to appear again. Meanwhile, whilst the night sky in spring abounds with some wonderful galaxies, most of these are really too small for my set-up to resolve properly. However, in the absence of larger DSO objects I have had to make do with these and have been pleasantly surprised by some of the results obtained.

The outcome of Leo Triplet and Markarian’s Chain were particularly good and demonstrate the superior abilities and power of the camera. Compared to the Canon 550D, when used with the William Optics GT81 refractor and a x0.80 field flattener, the ZWO 1600MM-Cool’s sensor produces a notably larger image with much greater sensitivity. As a result detail of all three galaxies that form the Leo Triplet M65, M66 and the end-on view of NGC 3628 is quite apparent and in another image, the spirals of the very small M61 galaxy can be clearly seen, though the quality is poor.

Leo Triplet – M65 (top right) M66 (centre right) NGC 3628 (lower left) Leo Constellation: William Optics GT81 & ZWO 1600MM-Cool + x0.80 field flattener | 60 sec 20 x L, 5 x RGB + full calibration, Gain 300 Offset 10 @ -20C | 21st March 2017

As expected the size of the data set from LRGB imaging with the camera is prodigious and furthermore, requires great care to organise before processing if mistakes are to be avoided. In the case of Markarian’s Chain I experimented with binning – only to learn later that it has no effect with CMOS sensors – which reduced the file size of the RGB and calibration images. Nonetheless, in all there were still 140 images with a combined file size of 1.6 Gigabytes! Notwithstanding, the benefits of LRGB imaging with this camera and EFW outweigh such problems and nowadays an extra storage disk is relatively inexpensive. Only processing power could perhaps be a problem if using an older PC but my 64-bit + i7 chip +16 GB RAM laptop computer has so far dealt easily with data processing very well.

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The difference between imaging and processing with a DSLR and the ZWO CMOS mono camera has been much greater than I anticipated and required more adjustment which I am still dealing with – the learning curve is steep! Notwithstanding, the experience previously gained using a DSLR has proved invaluable and I would not like to take-on LRGB imaging from scratch; I’d like to think that my adage of walk before you run once again has paid off. This camera is very exciting and I am confident that when the autumn and winter skies eventually return the new palette now in my hands will reap great rewards – can’t wait.

Markarian’s Chain | Subs 60 sec – see table for details Gain 300 Offset -30C | 18th April 2017

M61 piral Galaxy in Virgo Cluster | William Optics GT81 & ZWO 1600MM-Cool + x0.80 field flattener | L 30 x 40 sec RGB 3×20 sec + full calibration Gain 75 Offset 15 -30C | 2nd April 2017

Brave New World

April 11, 2017 by grahamrob in Deep Sky Objects, Equipment, General Astronomy, Imaging, Processing, Software and tagged Narrowband, Photography | 6 Comments

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In my quest to understand astronomy and in particular the big picture, I have just successfully completed another MOOC course at the University of Edinburgh on the Higgs Boson and particle physics. From earlier studies which included the Special Theory of Relativity and the Universe, the next step was obvious: moving from the very big to the very small in order to better grasp where we might be with the elusive unified theory and I was not disappointed. An added bonus to the course was the participation of Professor Peter Higgs himself, in which he discussed how he had arrived at his conclusions and the development of subsequent matters that led to the actual discovery of the Higgs Boson at the Large Hadron Collider in Cern, Switzerland in 2012; watching and listening to him speak felt like having a personal chat with Einstein and was quite a privilege!

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A chat with Professor Peter Higgs!

Frankly I found the nature of the subject very difficult and at times bewildering but its potential impact on astronomy was finally something of an epiphany for me. The Higgs and related items results in two profound results:

There was no Big Bang.
The existence of a multiverse, of which our Universe is but a part.

I am not sufficiently able to articulate how these conclusions are arrived at nor is this the place, but when the full content of particle theory, the Higgs, General Relativity are applied to cosmology, the aforementioned outcome is, like all good science, simple and beautiful – click here for lecture notes Higgsmooc part1 + Higgsmooc part2 and accompanying presentations 7.11_Quantum Vacuum_& Cosmology + 7.12_The HB_scalarfieldsand inflation.

I’m pleased to say there have also been other breakthroughs for me since achieving first light with the ZWO 1600MM-Cool CMOS camera. I am still at the experimental stage and with the spectacle of the winter sky rapidly departing, suitable objects are much more limited, with the few remaining HII objects low and very far to the west of the early evening sky. However, before the Milky Way disappeared completely I managed to obtain some useful imaging experience by targeting some old favourites.

Passing Shots: Orion & Rosette Nebulae

Having already battled a number of issues with the new camera – basic LRGB image capture, using Astro Astronomy Tools, achieving focus, guiding, alignment, processing and post-processing – for the moment everything has come together, including some warmer nights and clear skies. Over a few evenings I therefore undertook imaging in LRGB as well as Ha, OIII and SII, with some excellent results that augur well for the future.

The camera’s sensitivity and ability to image at short exposures enables much less imaging time than conventionally used with CCD cameras – one of the reasons I decided to purchase this camera. In addition, shorter exposures make perfect alignment and tracking less important, though still a desirable set-up. The downside is it produces a prodigious number of images, which leads to a somewhat challenging processing burden – but it’s worth it.

Despite my DSLR experience, CCD processing and especially post-processing, is significantly more complex. I was surprised to find only one decent online video on LRGB processing by Rankin Studio, without which the task would have been even more difficult and taken much longer to learn – thanks David. Ironically I have found narrowband processing easier, probably because there are just less filters and resulting image sets required, however, the restricted wavelength also provides whole new opportunities that I’ve already started to exploit.

Orion Nebula + M43 & Running Man Nebulae in Ha: William Optics GT 81 & ZWO 1600MM-Cool + x0.80 field flattener | 15 x 180sec Gain 139 Offset 21 @ -18C & full calibration | 25th March 2017

Just before they disappear from our night sky until next winter I was fortunate to be able to image both the Horsehead and Orion nebulae, everyone’s favourites and I’m no exception. With limited time available in the early evening sky it was only possible to capture a limited number of images before it moved outside my view in the west but even with these few images the power of the camera has already become self-evident.

Horsehead Nebula in Ha: William Optics GT81 & ZWO 1600MM-Cool + x0.80 field flattener | 19 x 180 secs Gain 139 Offset 21 @ -18C & full calibration | 27th March 2017

Given the need to use less filters and thus less time I have started out with narrowband imaging – as a completely new medium for me that holds great promise aesthetically and scientifically, I was also keen to give it a try and on this occasion used Ha and OIII. Having sorted an earlier problem with the EFW managing the filters is a breeze and can easily be automatically sequenced in the APT capture software. Notwithstanding, as previously indicated image capture is really only just the start – though good data is always the key to the final image – and processing and post-processing is both complex and takes considerable time.

Orion Nebula in bi-colour: Ha red channel + OIII green and blue channels

Ha red channel + OIII green channel

OIII green + blue channels

On this occasion the individual Ha subs are themselves very revealing, showing new details when compared with previous DSLR images. But it is with the bi-colour image that the exciting opportunities provided by using narrowband imaging become apparent – I can see I’m going to enjoy this! I’ve also taken the opportunity to further explore and understand the nature of these types of images and their constituent parts by manipulating the colour channels, with some startling results.

Rosette Nebula in HOS: William Optics GT 81 & ZWO 1600MM-Cool + x0.80 Field Flattener | 15 x 180 sec Gain 300 Offset 10 Ha, OIII & SII @ -20C + calibration | 24th March 2017

Not far from M42 is another of my favourites which I’d already used to achieve First Light with this camera using Ha – the Rosette Nebula (NGC 2237, 2238, 2239, 2244 & 2246). This time I decided to use all the narrowband filters – Ha 656nm, OIII 672nm, SII 500nm all 7nm bandpass – and subsequently experimented with processing using the Hubble Palette with stunning results. As the name indicates, this technique was originally developed for processing images taken with the Hubble Space Telescope which put simply, uses different mixes of each narrowband filter in different processing channels e.g. Ha in the red channel, OII in green and SII in blue, for short known as HSO.

Rosette Nebula in SHO

The outcome of my new adventure into narrowband imaging has been nothing less than a revelation. Like so much of my preceding astroimaging, I knew about much of it before but doing it yourself and seeing the results is both exciting and very satisfying; like Peter Higgs I feel I have entered a new world!

First Light

March 28, 2017 by grahamrob in Equipment, Imaging, Processing, Software and tagged Camera, Filter, Narrowband | 5 Comments

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If nothing else, I have learned from life – walk before you run. I have spent the past three years trying to learn about astronomy and astrophotography using a DSLR but late last year decided it was time to raise my game. I was reluctant to go to a CCD mono camera as it involves greater complexity and, perhaps more significantly, during the aforesaid period clear skies have been in very short supply – making long, guided exposures over protracted periods something close to impossible where I live. However, with the recent advent of the new CMOS cameras and their rave reviews, against my better judgement I took the plunge and bought a ZWO ASI 1600MM-Cool with a matching ZWO x8 EFW and 31mm LRGB, Ha, OIII and SII filter set.

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Wow! As expected, it’s a whole new world compared to DSLR and, as well as continuing week-after-week cloud cover, I have been battling with numerous set-up and processing issues. Still, rule number one with this hobby is patience and perseverance and I’m pleased to say I have just achieved First Light with the camera.

At first I set up the camera indoors on a tripod to test the equipment and quickly found that the camera and EFW would not work together; in addition to a USB 3.0 data socket, the camera also has two useful USB 2.0 sockets which can be used to power and control other equipment. After more than 3-weeks, much help online and a mixed response from the manufacturer, ZWO suggested I try another USB driver which they sent me and it worked – so why not supply that in the first place or ensure users are aware of the issue and provide a solution from the outset? Whilst the actual equipment is well specced, well made and well priced compared to CCD camera – though far from cheap, I found ZWO’s web-based technical guidance and general support poor and would expect better with such expensive equipment. In retrospect, perhaps it is not a surprise as I had a USB problem when I purchased their ZWO ASI 120MC camera, with a similar response and outcome i.e. there is a theme here, which is a pity as their equipment itself is innovative and very well made.

During brief periods between the clouds I subsequently managed to try-out the camera in order to understand focus, capture and processing. Despite prior experience with the DSLR and software, this turned out to be new territory which I am still exploring. Briefly:

Focus – With the new camera I was faced with two fundamental focusing issues:

Establishing the correct optical train – I want to continue using the William Optics x0.80 focal reducer with the ZWO camera, thereby increasing the speed of the scope from f5.9 to f4.72. I therefore purchased a Canon EOS adapter to use with the existing EOS convertor which has previously worked successfully with the DSLR. Despite the apparent complexity, the resulting set-up is within 0.50mm of the optimum distance and seems to work OK – with one exception. Whilst the locking pin on the EOS adapter works i.e. it locks, there is some unacceptable lateral play, which for now I have solved with the addition of a piece of electrical tape! I’m advised this is normal for such adapters but it seems like a poor product to me if this is the case.

Operating focus – after months of battling with focus when I started out DSLR imaging, I eventually discovered the Bahtinov mask and assumed this wonderfully simple method would work just as well with the new ZWO camera; of course, after my initial trials it was apparent this wasn’t going to be the case. Not that the mask doesn’t work but in order to achieve good focus with the smaller pixels of the ZWO ASI 1600 requires much greater accuracy, which I’m pleased to say has now been achieved by using APT’s Bahtinov Aid (based on Neils Noordhoek’s Bahtinov Grabber), so that I am now getting much better results. However, as the focus point can change with seeing conditions and when using different filters, it is apparent that I’ll need to return to this matter again to finesse the operation, probably by using an electronic focuser.

Capture – At the heart of my philosophy is the KISS principal – Keep It Simple Stupid! When working with the DSLR I therefore only ever used the Canon EOS Utilities software for image capture – it is simple, did what I needed and worked. Moving to a mono camera with filters, the increase in complexity is exponential and inevitably requires more sophisticated image capture software. Judging by the experience of others Sequence Generator Pro seems to be one of the best low cost programmes that will do this job and I have purchased a copy for US$99 and the accompanying Framing and Mosaic Wizard for an additional US$39. However, in applying the KISS principal during the early stages of getting to know and understand the new equipment and processes, for now I’m using Astro Photography Tool (APT) – something I’ve had for a while but not used before. It is a very capable programme that manages sequencing, cooling, filter management etc. well, with excellent support from its author Ivo but importantly seems easier to use than SGP, albeit inevitably with its own idiosyncrasies. It’s early days but so far so good.

Processing – Mono images differ in a number of fundamental ways to DSLR other than just colour, which requires a quite different approach to processing and post-processing, in particular:

the images are FITS not RAW;
mono images are taken with a variety of filters which subsequently need to be compiled.

Despite successfully working with Deep Sky Stacker (DSS) for some time, I was not aware of any changes required when processing FITS files, which are the product of the ZWO 1600 camera; useful pre-assessment of the files can be carried out using the ESA/NASA free Fits Liberator software. As a result my first try of the Beehive Nebula based on just Luminance subs was covered in bizarre ‘green spider-like’ artefacts after stacking in DSS. These disappeared when transferred into Photoshop but then became covered in Bayer matrix-like coloured squares!

M44 Beehive Cluster Luminance only – stacked correctly

FITS files stacked wrongly in DSS

Bayer-like matrix in Photoshop

Thanks to help from the SGL Forum it was apparent that I had failed to turn-off the FITS colour option in Settings before stacking – unchecking this and restacking immediately resulted in a half-decent image of the open star cluster. Meanwhile, since purchasing the ZWO camera I have read and watched numerous videos on post-processing and using LRGB files available online for practice, I have been able to start experimenting with this technique prior to obtaining my own data from the new camera. It is much more complex and I’ve got a long way to go but the experience gained from DSLR processing has nevertheless helped immensely; walk before you run pays off in the end!

And so last week I managed my first reasonable image of the Rosette Nebula (NGC 2244) using only Ha-subs, which this object has in abundance. I consider this marks the camera’s First Light and am pleased with the result but realise there’s still much more to learn, weather permitting!

Rosette Nebula in Ha | William Optics GT81 + ZWO ASI 1600MM-Cool & x0.80 focal reducer + guided | 15 x 180 secs + darks & bias calibration Gain 300, Offset 10 | 21st March 2017

This guided image is 15 x 180sec Ha-subs + darks and bias, gain 300, offset 10 + minor stretching in Photoshop. The corners – particularly the bottom right – look like there may be some vignetting in the stacked image? I haven’t managed to achieve any decent flats yet (another story) but I assume these would help eliminate this effect? However, I am surprised as I’m using the ZWO x8 EFW with larger 31mm filters, which with the focal length of 382mm (f4.72) should not result in vignetting.

Clearly my experimentation is ongoing with this new technology and I particularly need to understand better what is the ‘best’ gain and offset setting for different types of objects.

Whilst the CMOS chip is bigger than standard CCD sensors it is still smaller than a standard DSLR and with smaller pixels too (3.80nm v 4.30nm), the result when used with the focal reducer is a 29% reduction of the field-of view from 3.34^o x 2.23^o to 2.65^ox 2.0^o, which on-screen translates to increased magnification and allows me to get at some of the galaxies which hitherto have been too small; the benefit is minor but is worth having nonetheless.

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From Cloudy Nights Forum – compiled by Jon Rista

All-in-all the ZWO ASI 1600mm-Cool is an excellent piece of kit that has the potential to open up new vistas for my astroimaging. At a fundamental level it does all the basic stuff very well and the addition of cooling is a major improvement which reduces noise still further. I’m particularly looking forwards to experimenting with narrowband and bi-colour imaging – not least in order to keep working when the Moon’s about, unlike broadband imaging. However, the cameras intrinsically low read noise and ability to capture fine detail using only short exposures is surely set to mark the next revolution in astrophotography and furthermore reduces the need for very precise guiding; it’s clear the other manufacturers are scrambling to catch-up with this leading edge technology. Timing is everything in life and I’m pleased to be part of this hobby at such an exciting moment.

Arctic Antics

March 7, 2017 by grahamrob in Astronomy holidays, Earth, General Astronomy, Imaging, Processing and tagged Aurora Borealis, Norway, Photography, Venus | 2 Comments

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The globe pictured above on the island of Vikingen marks the location of the Arctic Circle off the western Norwegian coast. However, surprisingly the position of the Arctic Circle is not fixed – as of 28 February 2017 it was 66°33′46.6″ north of the Equator but changes depending on the Earth’s axial tilt, which itself varies within 2° over a 40,000-year period due to differing tidal forces that occur as the Moon’s orbit changes around Earth. The region north of the Arctic Circle is famous for the midnight sun in the summer and its corresponding 24-hour darkness during the winter months, with major implications for life itself, as well as contrasting scenery and photographic conditions unique to this hostile region.

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During the last two weeks of February, when the return of limited daylight has just begun to mark the end of winter, I travelled by ship along the entire western and northern coast of Norway close to the Russian border, spending much of the time within the Arctic Circle. The area is famous for its beautiful scenery, in particular the fjords which typify the coastline and for time immemorial have posed a significant challenge to all seafarers passing this way.

Looking north at Norkapp 1,306 miles to the North Pole.

Me at 71 10’ 21”N. Nordkapp: the most northerly point on the European Continent.

Our ship, the Richard With, was named after the Norwegian captain who in 1893 pioneered this difficult sea passage which we took from Bergen to Kirkenes and back. Today a fleet of 12 ships are operated by the original Norwegian company Hurtigruten on a daily basis providing ferry transport for goods, vehicles and personnel, as well as a base for tourists seeking a view of the Northern Lights – in all the ship stops at over 30 ports in each direction.

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The Richard With in Kirkenes

Scenery doesn’t get better!

Mountains south of Harstad

Apart from the scenery, during the winter months the area north of the Arctic Circle is probably best known for the occurrence of the Aurora Borealis or Northern Lights (Norwegian – Nord Lys). A view of this feature is treasured by all who see them but for astrophotographers it will be one of their ‘must do’ images to acquire. The Aurora is caused by a solar wind originating from the Sun that consists of charged particles, which when drawn downwards at the Earth’s poles by the planet’s magnetosphere ‘excites’ atmospheric atoms which produce different coloured lights depending on the type of gas which is excited by the charged particles; a similar feature occurs around the South Pole called the Aurora Australis and is also now known to occur on Saturn and Jupiter. The lights are mostly green in colour (ʎ 557.7 nm), sometimes red (ʎ 630 nm) or blue (428 ʎ nm) and less commonly pink, ultraviolet or yellow, depending on the altitude and type of excited gas – which is mostly either oxygen or nitrogen. The resulting aurora takes the form of rapidly moving clouds or often curtains of light that dart across the night sky, constantly changing shape under the influence of the Earth’s magnetic field and does not disappoint when seen.

The Northern Lights are best imaged with a standard DSLR camera on a sturdy tripod, using a wide angle lens at full aperture, set at between ISO 800 to 1,600 and exposures of about 8 secs to 25 secs, depending on the brightness and quality of the light and the speed of movement of the aurora; focus and all other control needs to be operated manually for best results. On land a tracking mount, such as a Vixen Polarie, could be used to improve sharpness but on a moving ship set-up and technique is a more difficult.

In this case exposure needs to be carefully balanced in order to account for the ships movement – forwards + up-and-down on the water – and the quality of the aurora light. As exposures will always need to be greater than a few seconds, star trails are unavoidable and have to be dealt with in post processing as best as possible. I found imaging directly forwards or to the rear of the ship helped minimise this effect but still trails were still inevitable. Experimenting with various settings I found about 12 to 15 seconds exposure and ISO 1,600 generally worked quite well but varied depending on the sea conditions and nature of the aurora at any time.

Seagulls following the ship? No star trails, now you see them….

Now you don’t!

At such high latitudes it is still very cold in February and warm head-to-feet-to-hands clothing is absolutely essential. On this occasion, together with wind chill the temperature at the ships bow ranged from between -20^oC to -30^oC (that’s a minus sign!), making camera control very difficult and uncomfortable! I tried using an intervalometer for remote shooting but as settings have to be changed frequently by hand it was not very practical; I’m sure on land it would prove much more helpful. Furthermore, much of the time I had to hold the tripod down with some force as the wind was very severe.

Before the show starts – sunset at Trollfjord

Venus looks down on the Raftsundet passage through the eastern Lofoten Islands

Notwithstanding, I’m very pleased with the results shown below and would love to return again one day, perhaps in the summer – it is a truly different and very special part of the world – hat’s off to Richard With and all those who still sail these waters.

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AstroBites-1: Planetary Alignment

March 3, 2017 by grahamrob in General Astronomy | Leave a comment

Various astronomy matters turn-up that in the future I intend to record from time-to-time in WTSM as AstroBites, a shorter blog format than usual that will also be recorded separately in the index.

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This month has started with a new crescent Moon in Pisces that at sunset last night was in alignment with Mars and Venus. I stepped outside briefly at 6.30pm and managed to image this incidence, just. Although also in crescent form at the moment, with an apparent magnitude of -4.4 Venus was as always very bright. However, with an apparent diameter of 4.7 arc seconds and magnitude +1.1 at the moment, Mars is faint and very small but can just be seen in the image.

Moon & Venus in alignment + half-way in between, also in alignment, is Mars | Canon EOS 700D | 24mm f4 1/30 sec @ ISO800 | 2nd March 2017

Cropped image shows Mars covering about 4 pixels!

Nice but dim (& small)

February 14, 2017 by grahamrob in General Astronomy | Leave a comment

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The learning curve was steep in my first year of astronomy and to my dismay I soon learned that there was unfortunately no do-it-all telescope. The optical quality of the William Optics GT81 is excellent, which combined with a modified Canon 550D has provided me with good images of large particularly HII-type targets but the aperture and camera are much less suitable for capturing faint, small objects. However, with good alignment, all the equipment now working well together and an unusually prolonged period of good night sky conditions at the end of 2016, just for the fun of it I decided to try imaging some of the winter sky’s more challenging DSO features.

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With a x0.80 field flattener, the aforementioned telescope and camera produces a field-of-view of 3.34^ox 2.23^o at a resolution of 2.32” / pixel. As a result, anything less than say 10’ x 10’ in size is difficult to image and even at that scale it is very marginal. Despite my new guiding skill which allows longer exposures and thus captures more photons, small objects of +8.0 apparent magnitude or less are therefore something of a stretch to photograph. Nonetheless, on this occasion I set out to image four such targets in the region of 30^o and 60^o altitude as they passed the Meridian during the evening; the results were mixed but very interesting.

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All the following images were taken on 3rd December 2016 with a Williams Optics GT81 telescope + Canon 550D DSLR & 0.80 field flattener, with calibration & processed in Photoshop.

With the exception of something as large as Andromeda and M33, I’ve regretfully found that galaxies are generally beyond the capabilities of my current equipment. It was therefore no surprise that on this occasion M74 and M77 appeared as not much more than grainy smudges in the image – but they are there! However, clearly present is the spiral nature of the former galaxy and a number of other neighbouring galaxies are very apparent in the latter.

M74 spiral galaxy | 11 x 300 sec @ ISO 1,600

M77 spiral galaxy & friends | 10 x 300 sec @ ISO 1,600

Located within the Orion constellation, above the star Alnitak, though noisy the reflection nebula M78 came out surprisingly quite well, with part of the nearby Barnard’s Loop also evident towards the top edge of the main image and (I think) the orange giant star 51 Orionis shows near the bottom right-hand corner.

M78 reflection nebula | 12 x 300 sec @ ISO 800

But my most satisfying result of the night was M1, the Crab Nebula, one of the winter night sky’s iconic features. Although a little grainy, the filament structures and colours of this remnant supernova is quite visible.

M1 Crab Nebula | 13 x 300 sec @ ISO 800

All-in-all the experiment turned out well and was also good fun, though it is clear that better images of these nice but dim (and small) objects will have to wait until I own more suitable equipment.

chummy

Headhunter

January 31, 2017 by grahamrob in Deep Sky Objects, Equipment, Imaging, Widefield Imaging and tagged Orion | Leave a comment

Orion constellation January 2016

Orion stars + apparent magnitude

The latter part of 2016 was very productive, especially around the end of November and early December. Remarkably the clouds were completely absent for over a week, it was cold but the air was unusually dry and furthermore it was only just past the New Moon, all-in-all excellent conditions for astrophotography. With Orion starting its Christmas-New Year parade across the night sky it was also a good time to investigate other parts of this fascinating constellation which I had not previously imaged.

Depicted in Greek mythology as Orion the Hunter, attention is most often given to the ‘sword’ that hangs from his belt – formed by three open star clusters which notably includes M42 the Orion Nebula. Located just above, in the eastern region of the Hunter’s so-called belt and is NGC 2014 the Flame Nebula and the nearby Barnard 33, or as it is more famously known – the Horsehead Nebula. I have imaged these and other targets such as the reflection nebulae M78 just above the aforementioned Flame Nebula and the difficult to image IC 2118, better known Witch’s Head nebula, situated just beyond the bright star Rigel which forms the Hunter’s left foot.

Barnard’s Loop & Lamda Orionis Nebula + Rosette Nebula on far left (east) : Vixen Polarie & modded Canon 550D + Sigma UWA lens @ 20mm | 14 x 240 secs @ ISO 800 | 14th January 2016

However, a much wider view of Orion shows the presence of very large regions of HII nebulosity enveloping the main constellation, which altogether form the Orion Molecular Cloud Complex. Most notable of these areas is Barnard’s Loop, a large HII cloud that arcs across some 10^o of the sky encircling the lower, eastern section of the Orion star asterism. I have had some limited success imaging the Loop before but on this occasion I tried some of the other areas of HII nebulosity which are located within the higher parts of Orion the Hunter.

The combination of the William Optics GT81 and their x0.80 field flattener reduces the focal length from 478mm to 387mm and increases the speed from f5.9 to a fast f4.72. Apart from removing distortion at the periphery of the image, when used with the Canon 550D DSLR the field flattener increases the field-of-view by a staggering 64% or from 2.67^o x 1.70^o to 3.34^o x 2.23^o. This has its shortcomings when imaging galaxies which generally have a small FOV but is perfect for large DSOs such as my first target.

the-hunter-crop

The basic ‘anatomy’ of the Hunter is outlined by a number of stars that form his legs, waist and arms, with a club held above in his right hand and either a shield, lion’s pelt or bow held outstretched in his left hand. On this occasion I first attempted to image his head; catalogued as SH2-264 it is otherwise known as the Lamda Orionis Nebula or sometimes the Angelfish Nebula. This very large HII cloud is located, as would be expected, at the top of the Hunter’s body and should be a good target for the aforementioned equipment with a modded camera, now aided by the longer exposures from my newly found PHD2 guiding expertise.

Upper Orion constellation & Lamda Orionis setting

This HII-feature is broadly centred on the giant double star Meissa or Lamda Orionis, which is itself at the apex of a triangle with the red giant superstar Betelgeuse to the east and blue giant star Bellatrix to the west and thus forms the outline of the Hunter’s shoulders. Some 8^oin its entirety, the Lamda Orionis Nebula is enormous but consists mainly of very faint Ha-light, so that despite good imaging conditions, long exposures and good framing I was unable to obtain any sign of its presence on this occasion.

Frankly I was surprised there wasn’t at least a vestige of red Ha-light somewhere in the image but for now I will have to admit defeat. However, looking back I can see the Hunter’s head in previous wide-field nightscapes of Orion taken in January 2015 and 2016. Notwithstanding, together with other nearby stars Meissa forms the open star cluster Collinder 69, which on this occasion fortunately produced something of a pleasant alternative image.

Meissa double star & Collinder 60 open star cluster | William Optics GT81 + modded Canon 550D & 0.80 FF + Guiding | 14 x 300 secs @ ISO 800 & full calibration | 4th December 2016

sh2-264-041216-invertedannotated-large

Subsequently I slewed the telescope and camera to another, nearby HII-cloud, this time situated along the Hunter’s right arm, just above his elbow. Discovered by amateur Californian astronomers Harold and Charles Lower in 1939, at about 45’ x 45’ size H2-261 or Lower’s Nebula is much smaller than the Lamda Orionis Nebula but also faint and difficult to image. However, here I did manage to capture something of the Ha-feature, albeit that the image was rather noisy when processed and yes I did apply Gradient Exterminator, though it doesn’t look like I did.

Lower’s Nebula SH2-261 | William Optics GT81 & modded Canon 550D + FF + guiding | 12 x 30 sec @ ISO 800 | 4th December 2016

The Orion Molecular Cloud Complex is one of the best known areas for star formation that is closest to Earth and provides an abundance of wonderful imaging targets at this time of the year. However, as previously experienced with Barnard’s Loop, the large areas of HII cloud that encircle much of Orion’s constellation can be elusive and difficult to image, which will probably require a camera of greater sensitivity and many more exposures to achieve success. However, on this occasion the image of Lower’s Nebula was some consolation as I continue my quest for Orion’s scalp.

Reflections – 2016

January 1, 2017 by grahamrob in Autoguiding, Comments, Deep Sky Objects, General Astronomy, History, Imaging, Widefield Imaging and tagged Andromeda, Arizona, Einstein, Galaxies, Messier Objects, Milky Way, Orion, Photography, Science, Utah | Leave a comment

2016 was the second full year of Watch This Space Man (WTSM) and once again it’s been something of a mixed period. Faced with a major, apparently insoluble problem, by mid-year I actually thought of giving up but by year-end it’s all come good again, in fact very good. Reflections is a look back at the ups-and-downs of the past year, astronomically speaking and a peek into the next twelve months, which one way or another could determine the future of my astrophotography.

wtsm-visitor-map

I have been astonished by the interest in this website, with some 7,000 visits and 14,000 page views from more than 65 different countries during the year, the list is quite amazing. Though I write this blog for myself, I am increasingly aware of this unsolicited readership – you are all most welcome and I would be very pleased to hear from anyone who would like to get in touch with queries, comments or just to say hello – contact details are in the Contact drop-down section of the About main menu.

reflections-2016

JANUARY TO MARCH

The year started poorly, got much worse, then finally improved. Using my recently acquired Vixen Polarie I was pleased to start the year with an image of Barnard’s Loop, something notoriously difficult to photograph and had previously eluded me. Sadly I was not so successful with the Milky Way and have reluctantly come to the obvious conclusion that this can only be imaged in much darker skies than I’m ever likely to experience located just to the south of London and close to Gatwick airport!

As Orion starts to move on after Christmas and especially from February, I struggle to find suitable imaging targets; Coma Berenices and other constellations at this time contain numerous galaxies but they’re mostly too small for my William Optics GT81 and otherwise what might be doable I have already done before. Notwithstanding, after looking carefully I came across two HII nebulae still lurking in the early evening. The size and Ha-light of NGC 2174 Monkey Head Nebula and IC 2177 Seagull Nebula, provided just what I was looking for. Located close to Gemini and Monoceros constellations, both these DSOs are within the part of the Milky Way section of the sky, an area that thankfully produces many other similar opportunities at this time of the year for a modded DSLR camera.

Monkey Head Nebula

It’s often the small things that either alone or cumulatively can help transform the outcome with astrophotography. The quarterly period finished by acquiring two new pieces of equipment, one which could help improve the set-up and operation of the mount, the other which I hoped would help me move to the next level of imaging.

When working in the dark and worse still in the cold, the ergonomics and general convenience of operating the equipment becomes paramount. Since starting to use EQMOD-ASCOM and Cartes du Ciel for mount control and tracking, I encountered the problem of having to be in two places at the same time; in this case co-ordinating adjustments at the mount and the computer, in particular when making and syncing star alignments. The answer to this conundrum was a gamepad, which I purchased for a nominal sum on eBay and after watching the inimitable Chris Shillito’s video on setting up and using a gamepad with EQMOD-ASCOM, have never looked back. By using the gamepad the telescope can now be manually slewed, centred and synced on any object whilst remaining at the scope, thereby making the process of alignment much quicker and convenient.

Wireless gamepad provides extensive control of critical alignment functions without being at the computer: front x4 buttons are assinged to set various slew rates, the mount-telescope can be directed either via the rear (right) joystick or POV buttons on the right, button-1 parks and button-2 syncs. Other buttons have yet to be allocated.

Starlight Express Lodestar x2 Guide Camera can be used either via the mount’s ST4 port or via ASCOM and the computer for pulse guiding.

At the end of 2015 it was my intention to start guiding in the coming year, a prerequisite for the long exposures necessary to increase data capture and thus hopefully improve image quality. I had originally intended to use my ZWO ASI120 MC camera together with a William Optics 50mm guidescope for this purpose but there always seemed to be other problems to overcome first and to be honest, I was somewhat intimidated about tackling the black art of guiding. I was finally prompted to do something about this when in March a second-hand Starlight Express Lodestar X2 autoguide camera came up on the UK Astronomy Buy & Sell. From previous research I knew this was considered to be a very good and popular guiding camera, so as it had only just been posted on the website, I immediately went for it and was successful – timing is everything. Inevitably I had problems setting-up and in particular getting the camera to focus – which was my own fault – but by the end of March I was guiding! Truth is my guiding at this stage was not very good and I needed to look further into using the PHD2 guiding software but nonetheless, the equipment was at least now working together!

No	Date	Object*	Name
1	07/01/16	Orion	Barnard’s Loop
2	14/01/16	Orion	Barnard’s Loop
3	02/02/16	Catalina	Comet
4	02/02/16	Milky Way
5	10/02/16	IC 2087	Dark nebula
6		NGC 2174	Monkey Head Nebula
7		IC 2177	Seagull Nebula

*Record of quarterly photographic images taken in 2016

APRIL TO JUNE

After finishing the previous quarter on something of a high note by getting PHD2 working for the first time, I was now hopeful that from herein my exposures and thus images would show improvement – unfortunately I was soon to be very disappointed.

In April we went on a trip to the Southwestern USA – something of a geological pilgrimage for my wife and I (we are both geologists) – to see the Grand Canyon, Monument Valley, Bryce Canyon and Zion National Park as well as many other similar areas. Prior to going I had purchased a Sigma 10mm-20mm wide-angle lens in anticipation of all the big views that are characteristic of the region and was not disappointed by the lens or the scenery.

Being largely an uninhabited wilderness area, I also took the Vixen Polarie with a plan to at last capture images of the Milky Way. Unfortunately, whilst I had checked the sky beforehand on Cartes du Ciel, I think I must have made an error with the dates. We did get clear skies but unfortunately it turned out to be a full moon whilst there, which ruled out any hope of seeing, let alone imaging the Milky Way; oh well there’s always another day and it’s not going anywhere in the meantime. Notwithstanding I did manage some pleasing nightscapes at Monument Valley and Bryce Canyon.

IMG_6235 (Large)

Given my initial guiding success prior to visiting the USA, I had been looking forwards to getting to grips with improving guiding and imaging on my return. Furthermore, on 6^th May there was a rare solar transit of Mercury and in preparation, the week before I set up and tested all the equipment and then successfully took some test images of the Sun using a Baader solar filter. All was well on the appointed day which was also fortunately clear and sunny, so that shortly before contact I was all set and ready to try and capture the movement of a small black dot (Mercury) across the face of the Sun. Unfortunately it was not to be and the weeks that followed almost marked the end of my still nascent hobby of astrophotography!

In short, EQMOD crashed when I turned on the DSLR camera to image the transit! I tried re-booting and checked every other piece of equipment numerous times but to no avail. I subsequently spent weeks trying to track down the problem, checking and re-checking every cable, piece of equipment and updating or reinstalling all the relevant software without success. The nature of the problem strongly suggested there was a conflict between EQMOD-ASCOM and the camera and I therefore turned to the EQMOD forum for help, without success. Somewhat late in the day and by now desperate, I posted the issue on SGL and quickly received a reply from someone who had had a very similar problem, which though also very difficult to identify, turned out to be a very small break in the outer cover of the DSLR AC/DC power adapter cable. It’s not clear to me why this matters but I bought a new adapter and as they say, Bob’s your uncle, it worked! I have looked very carefully at my adapter and cable and can see nothing wrong but am very thankful for the advice.

AC/DC Adapter: How can something as basic as this cause so much disruption?

It seems ridiculous that this very minor problem was nearly terminal but just in case it happens again I have since bought another spare power adapter. Together with my daughter’s wedding in early June and the adapter meltdown, imaging for two of the three months during this period was almost non-existent. Still by July I was ready to start again but by then there was no astronomical darkness!

No	Date	Object	Name
8	April	USA	Monument Valley etc
9	06/06/16	M5	Globular cluster
10		M13	Globular cluster
11		M57	Ring Nebula

JULY TO SEPTEMBER

After the carnage of the last quarter, I was then unable to resume imaging in July due to travel commitments. So I used what time was available to improve my knowledge of PHD2 and once again, check everything was now working ready for the return of astronomical darkness and better night skies from 20^th July; I am of course now paranoid of another similar breakdown. At the start of August I manged to obtain a just passable image of the Eagle Nebula for the first time. Then shortly afterwards on the evening of 11^th / 12^th August, clear skies produced a decent night for viewing and imaging a few of this year’s Perseids meteor shower. But it was at month-end and continuing into September that my imaging in 2016 finally took off.

m27-comps-paintfile

At that time the weather was consistently dry and warm, providing more than a week of clear skies and almost nightly imaging. Dark nebulae are interesting features I’d hitherto not recognised as imaging opportunities and was therefore intrigued to successfully image the E-Nebula at this time. Thereafter I used the opportunity of the weather window to experiment with PHD2 by using M27 the Dumbbell or Apple Core Nebula as a control imaging object. Of course, each year is different but I’ll try to use any similar conditions in the future to sort out and develop old and new techniques, such unusual moments are precious for UK astronomers. At the end of nearly two tiring weeks I had PHD2 working quite well and have not looked back since. As a result of this work soon thereafter obtained good images of the Andromeda Galaxy, as well as the Veil, Crescent and Ring Nebulae.

No	Date	Object	Name
12	07/08/16	M16	Eagle Nebula
13		M11	Globular
14		B142-3	Dark E-Nebula
15	11/08/16	Perseids
16	23/08/16	LDN 673	Dark Nebula
17		NGC 6781	Planetary Nebula
18		M27	Dumbbell Nebula
19		Albireo	Double star
20		Moon
21	28/08/16	M11	Globular cluster
22		NGC 6905	Blue Flash Neb
23		Albireo	Double star
24		15 Aquilea	Double star
25		NGC 6960	W Veil / Witch’s Broom
26		M32	Andromeda Galaxy
27	29/08/16	M27	Dumbbell Neb
28		NGC 6960	W Veil / Witch’s Broom
29		NGC 7814	Pegasus galaxy
30		M15	Globular
31		M27	Dumbbell Nebula
32		M27	Dumbbell Nebula
33	08/0916	M27	Dumbbell Nebula
34		M27	Dumbbell Nebula
35		NGC 6960	W Veil / Witch’s Broom
36		NGC 6960	W Veil / Witch’s Broom
37		M31	Andromeda Galaxy
38	11/09/16	NGC 6888	Crescent Nebula
39		NGC 6992	Eastern Veil (NGC 6995)
40	13/09/16	M57	Ring Nebula

OCTOBER TO DECEMBER

Normal conditions resumed later in September and into the final quarter in the form of overcast skies. A minor break in the weather allowed a crack at the M33 Triangulum Galaxy towards the end of October but only in late November did another clear period occur, by which time the winter sky had arrived and temperatures had fallen to nearly 0^oC.

M33 Triangulum Galaxy – consisting of some 40-billion stars, the photons in this image have travelled 3-million light years in order to reach my camera sensor! | WO GT81 + modded Canon EOS 550D & FF guided | 18 x 300 secs @ ISO 800 & full calibration | 22nd October 2016

Unfortunately I am unable to establish a permanent observatory here at Fairvale and have to take-out the bring-in all the astronomy equipment each time. Apart from being inconvenient this has two practical disadvantages: (i) it can be uncomfortable even unpleasant working outside in such temperatures, and (ii) it is necessary to polar and star align every time; on occasion when using SynScan and EQMOD-ASCOM it can take up to 2-hours before starting imaging. Fortunately, I think I have now sorted out both these problems which should greatly help in the future.

By re-configuring the computer, mount and camera wiring, combined with establishing a wireless link between my tablet and the computer, once set-up I can now control most of the functions from indoors. The comfort of being indoors benefits operating in general and especially thinking, which can be quite difficult when astroimaging and made even harder when it is cold.

With prolonged periods of clear weather in the second-half of the year, I was sometimes able to set-up and leave the equipment for a few days under a waterproof cover, which meant that from day-to-day I could be up-and-running each time in less than 30 minutes! However, I expect this will only rarely be possible and nightly set-ups are likely to continue to be the norm. Fortunately, I have also recently discovered two techniques that should help both streamline and improve star and polar alignment in the future.

In addition to guiding, PHD2 has a very good polar alignment facility that eliminates the use of the SynScan handset and enables the procedure to be carried out from the computer; it can also be undertaken without sight of the Polaris star, which is a major problem at Fairvale Observatory where it is totally obscured by my house. At times when the mount can be left outside, I can also save and subsequently re-use the star-alignment model in EQMOD-ASCOM. All-in-all these and other procedures have made a very positive impact on my astronomy and astroimaging. The outcome of these changes led to a decent sequence of imaging with which to finish the year and, furthermore, hopefully provides a strong foundation for continuing improvements in 2017.

No	Date	Object	Name
41	22/10/16	M15	Globula cluster
42		M33	Triangulum Spiral Galaxy
43	28/11/16	M45	Pleiades
44		NGC 2024	Horsehead Nebula
45		M42	Orion Nebula
46	29/11/16	Hyades	Open star cluster
47		NGC 2244	Rosette Nebula
48	30/11/16	NGC 1499	California Nebula
49		IC 405	Flaming Star Nebula
50	03/12/16	M74	Spiral Galaxy
51		M77	Spiral Galaxy
52		M1	Crab Nebula
53		IC 2118	Witch’s Head
54		M78	Reflection Nebula
55	04/12/16	SH2-264	Lamda Orionis
56		SH2-261	Lower’s Nebula

ETCETERA

A few other astronomy and imaging related matters helped shape the past year for me. After coming across WTSM, I was surprised to be contacted by the Purley Photography Camera Club to give a lecture on astrophotography in March. I’m pleased to say the event went very well and, furthermore, the process of compiling the presentation beforehand helped expand my own knowledge of the subject too.

TTT Cover

In May I received a sun dial installed on a carved Purbeck Stone plinth as a retirement present. As a time piece it’s accuracy is limited but it is a beautiful addition to my garden and solar astronomy for which I am very grateful. By coincidence, later in the year I also came across a simple but charming sun dial set into the ground by the upper lake at Earlswood Common, a short walk from my home and Fairvale Observatory. Intriguingly it works by standing on a central stone, located depending on the season, and then uses your own shadow to read off the time – clever.

Sun dial at Earlswood Common

My new sun dial

In September we visited Lacock Abbey in Wiltshire, home of William Fox Talbot in the 19th Century – photography pioneer and notable for developing photographic fixing and printing. The photography museum there is very good and it was fascinating to see his place of work in the house, where the very first photographic print is also displayed. His contribution to photography is unique and today he is generally recognised as the father of modern photography.

william-henry-fox-talbot-with-camera-141697035181903901-141210123557

As a Londoner born and bread, I like to think I know the city well and over my lifetime have visited most of its unique sites, old and new. However, for some inexplicable reason I had never been to Westminster Abbey, so decided to put that right in November. It is, of course, a building of unparalleled history, with numerous graves and memorials of centuries of kings & queens, as well as scientists, explorers, poets, actors etc. Noteworthy amongst these for the astronomer is the physicist and mathematician Sir Isaac Newton and Second Astronomer Royal, Edmond Halley.

I must next give mention to the man who throughout the year dominated my reading, learning and thinking – Albert Einstein. His work during the early part 20th Century still dominates today’s physics and astronomy. We continue to make ground breaking discoveries that substantiate and build on his ideas that were originally postulated over 100-years ago. Pictures only recently obtained using the the Hubble telescope have spectacularly demonstrated the effect of gravitation lensing and in 2016 for the first time ever the existence of gravitational waves was confirmed. This year I therefore decided to understand the man and his work better. During the first half of the 2016 I read Walter Isaacson’s excellent biography of Einstein and have recently completed and 8-week Stanford University course on the Special Theory of Relativity. They were both very enjoyable, immensely interesting and time well spent.

CMB some 380,000 after Big Bang.

Einstein vindicated: gravitational lensing

Finally, this Christmas I was surprised and very pleased to receive a printed, bound copy of the WTSM blog for the period since its inception on 5th August 2014 until 10th November 2016. A lot of work has gone into producing this blog and I’ve always been concerned that somehow something might go wrong with the website or internet and it would all be lost. This book now safely preserves in print all the blogs and images posted during the aforementioned period. The production is generally very good and I have already enjoyed re-reading some of my blogs once again.

WTSM: The Book!

Favourite Images

As a result of the aforementioned issues, 2016 has certainly been a year of two halves. Having resolved the equipment problem and started to employ some very useful new techniques and software, I was eventually able to obtain some good images. My personal favourites in no particular order are shown here below:

Barnard’s Loop & Lamda Orionis Nebula : Vixen Polarie & modded Canon 550D + Sigma UWA @ 20mm | 11 x 240 secs @ ISO 1,600 + darks | 7th January 2016

Monument Valley by Night: order of buttes same as daytime photo above. Canon 700D + 10mm Sigma wide-angle lens | 20 x 15 secs @ ISO 6,400 | 10th April 2016

B142/3 Barnard Dark E-Nebula

M27 Apple Core Nebula | William Optics GT81 + 50mm Guide Scope & 10-point EQMOD-ASCOM alignment model | modded Canon 550D + Field Flattener | 3 x 300 secs @ ISO 1,600 & full calibration, 90% cropped | 30th August 2016

M31 | WO GT81 + modded Canon 550D & FF | 10 x 300 secs @ ISAO 1,600, darks + flats | 8th September 2016

First ever print, taken at Lacock Abbey 1835

The same picture by me September 2016

Round-up & goals for 2017

Despite the frankly awful start to the year, astronomically speaking 2016 finished on something of a high. Furthermore, contrary to initial indications I was in the end partially successful in achieving some of my objectives set out at the beginning of last year:

RECORD CARD – 2016
Goal	Specifics / Results	Outcome
*Increase imaging exposure times*	Improved equipment set-up and alignment and successfully started autoguiding with exposure times of up to 8-minutes.	DONE
*Improve processing*	Started using newer version of Photoshop CS2 + other related software. Improvement with post-processing using online tutorials and Nik Syzmanek’s booklet Shooting Stars.	GETTING THERE
*Start widefield imaging*	Purchased Vixen Polarie, with portability put to use in the USA but did not make UK dark sky sites as planned.	GETTING THERE

Getting better: PHD2 working screen 30th November 2016, DEC is good but room for improvement with the RA settings. Notwithstanding, the impact of tracking and image quality is noticeable.

download

I’m concerned about setting more goals or the forthcoming year but I think it helps, so here goes:

Improve processing: As the headmaster’s report would say “room for improvement” and I will try. I have purchased Warren Keller’s book Inside PixInsight, considered by many to be the gold standard of post-processing software but is a nightmare to learn – this may be a step too far for now, we’ll have to see – maybe 2018?

Expand and improve widefield imaging: First – use the Vixen Polarie as had been intended last year to obtain nightscape images at UK dark-site locations. Second – look at ways of using a widefield set-up with the mount more successfully.

Start LRGB imaging: I spent a lot of time in 2016 considering the question – what next? I am keen to image smaller DSO objects, in particular galaxies and was on the verge of purchasing a larger telescope – probably another refractor. However, after attending a talk by Nik Syzmanek, one of Britain’s foremost astrophotographers, I have come to the conclusion that the next step should probably be a move to LRGB imaging, which if successful probably has the greatest potential to improve my pictures – let’s hope so.

Looking back 2016 was a funny old year, which for me was defined by three experiences:

Despite two wonderful periods at the end of August and November the weather for astronomy was mostly awful, with cloud cover for weeks on-end and when it was clear, it was a full moon – frustrating or what?

I had already learned that patience and perseverance are required in large quantities for astroimaging but the equipment break-down in May and June was so severe and apparently insoluble that, together with the aforementioned cloudy skies, I really thought of giving up.

However, this time there is a happy ending: after I finally solved the equipment problem and started autoguiding, I feel I have eventually made some great strides with my imaging in 2016 which, furthermore, holds much promise for the coming year and I hope can record in WTSM’s Reflections at the end of 2017.

Watch this space!

Photons & Photography

December 20, 2016 by grahamrob in Deep Sky Objects, Equipment, General Astronomy, History, Imaging, Processing, Universe and tagged Einstein, Messier Objects, Photography, Science | 1 Comment

william-henry-fox-talbot-with-camera-141697035181903901-141210123557

I’ve been interested in photography from a young age. As I child I played with my parent’s Kodak box camera and, as far as I can remember, my first camera was a Kodak Brownie at the age of about nine. It’s a wonderful medium that I have now experienced for over 50-years, on land, underwater and now for astrophotography.

My cameras

I’d like to think I know a thing or two about photography by now; underwater photography and digital astrophotography have been particularly challenging in different ways but the latter is a real eye opener that has expanded my knowledge of digital imaging significantly. Capturing images of distant objects that can only be seen with the use of sophisticated equipment and complex processing also requires an in-depth understanding of light itself.

Basic working concept of digital sensors

Modern camera sensor

Having spent the first half of this year reading Einstein’s biography, I have recently started an online course at Stanford University on his ground-breaking Special Theory of Relativity. Einstein’s many insights into the physical world are profound, which more than 100-years on still challenge most of us to understand. Light was at the core of his famous 1905 paper, in particular it’s duality as a waveform and light quanta, or photons – defined as a quantum of electromagnetic radiation. His concept of the photoelectric effect has enabled the development of today’s digital camera sensors and CCDs. The core principal is the production of electrons as light shines onto a material, whereby the light (photon) knocks out an electron which can then be collected electronically – the basis of digital photography.

Camera obscura at Lacock

Camera obscura image

Lacock Abbey

In September I visited Lacock Abbey in Wiltshire, initially a 13^th century nunnery which is now run by the National Trust. Today it is better known as the home of William Henry Fox Talbot (1800 – 1877) – mathematician, astronomer and archaeologist but most famously the inventor and pioneer of photography, notably developing, fixing and printing. The window photograph below (left) was taken at Lacock Abbey in August 1835 and is recognised as being from the oldest ever camera negative produced by Fox Talbot, on the right is the same window in 2016.

First ever print, taken at Lacock Abbey 1835

The same picture by me September 2016

In the early 19^th century Thomas Wedgwood had made photograms – silhouettes of leaves and other objects – but these faded quickly. In 1827, Joseph Nicéphore de Niepce produced pictures on bitumen, and in January 1839, Louis Daguerre displayed his ‘Daguerreotypes’ – pictures on silver plates – to the French Academy of Sciences. Three weeks later, Fox Talbot reported his ‘art of photogenic drawing’ to the Royal Society, which subsequently became the de facto basis of modern film photography.

Fox Talbot’s desk in his study at Lacock Abbey

Fox Talbot lived and worked at the Abbey for most of his life. As well as an excellent museum, which details the history of photography and photographic processes, the house contains his rooms where he developed (no pun intended) the aforementioned inventions and is surely a ‘must do’ visit for any keen photographer. Like many at that time he was a polymath, with notable friends and accomplices who worked in similar and other scientific fields:

Sir John Herschel – astronomer, mathematician, botanist & chemist, Gold Medal winner and founder of the Royal Astronomical Society, son of William Herschel who discovered Uranus.

Charles Babbage – mathematician, philosopher, mechanical engineer, considered “the father of the computer”;

William Whewell – leading 19^th century scientist, recognised in the fields of architecture, mechanics, mineralogy, moral philosophy, astronomy, political economy, and the philosophy of science;

Sir Charles Wheatstone – physicist, inventor of stereoscopic photography, the telegraph & accordion;

Sir David Brewster – physicist specialising in optics, mathematician, astronomer & inventor of optical mineralogy and the kaleidoscope;

Peter Roget – physician, theologian, lexicographer and publisher of Roget’s Thesarus.

This particular group are now remembered by a table setting in the Abbey’s dining room, where they gathered for dinner; the mind boggles at the conversation!

Fox Talbot’s pioneering photography work preceded the early 20^th century understanding of light that arose from Einstein and its more recent application in semi-conductors as camera sensors, of which I am sure he would have approved. At that time the Universe outside of our galaxy was also unknown and he would have marvelled further at the thought of imaging other such distant galaxies such as M33 below; like photons, photography has come a long way since his death in 1877.

M33 Triangulum Galaxy – consisting of some 40-billion stars, the photons in this image have travelled 3-million light years to reach my camera’s sensor! | WO GT81 + modded Canon EOS 550D & FF guided | 18 x 300 secs @ ISO 800 & full calibration | 22nd October 2016

It’s All Relative

December 6, 2016 by grahamrob in Deep Sky Objects, General Astronomy, Imaging, Processing, Software, Universe and tagged DSO Imaging, Einstein, Monoceros, Orion, Perseus, Pleiades | 2 Comments

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I spent the first half of this year reading Walter Isaacson’s biography of Albert Einstein, which apart from providing a fascinating insight into the man and his work, whetted my appetite to understand better the science. Following previous success studying astronomy courses online, I set out to find a suitable programme to achieve this goal. As a result I enrolled for Understanding Einstein: the Special Theory of Relativity run by Professor Larry Lagerstrom of Stanford University, USA, which after two months I have just completed. spacetime

The course is a good mix of qualitative and quantitative information, which at times has been quite challenging but nonetheless proved very worthwhile. The lecturer is very clear and thorough, an essential quality when dealing with this difficult and often bewildering subject. Einstein’s paper On the Electrodynamics of Moving Bodies outlines the Special Theory and was just one of four published at about the same time in 1905 (“The Miracle Year”) which included: Brownian motion, Mass-energy equivalence (E=Mc²) and The Photoelectric Effect, the latter of which won him the Noble Prize. At the end I now feel I understand the basics of Einstein’s ground breaking science properly, which apart from being interesting provides valuable insight and understanding of the Universe and related issues of space and time.

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During this period I have also been thinking about how to improve my astrophotography and the way forwards. I’ll be on the learning curve for years to come and accept that there’s much I can still improve on using current equipment and processes but after more than 2-years astroimaging, mostly with a DSLR camera, I feel I have reached something of a crossroads and need to change tack in order to achieve more meaningful advances once again. Inevitably this is likely to mean new equipment and most likely a move to LRGB / Narrowband format. In the interim, whilst I consider the options, I have also been researching suitable capture / sequencing software, post-processing techniques and programmes. I am concerned that this will result in another level of complexity but I think it has to be done in order to progress – watch this space.

Continuing a trend that’s been apparent for the past year, clear nights have been something of a rarity since mid-September; this is a concern if I am to pursue astrophotography to the next level. However, high pressure was unusually dominant over Fairvale Observatory during the last days of November and cold, clear skies have provided good conditions for astronomy at last.

Getting better – PHD2 screen 30th November 2016: DEC is good but room for improvement with the RA settings. The impact on tracking and image quality is noticeable.

Whilst I have certainly not fully mastered guiding I am now routinely using PHD2. This in itself has probably been the major breakthrough this year, which with the aforementioned clear skies I wanted to take full advantage of. Hidden within PHD2 I have also discovered and am now starting to experiment with the on-screen drift align routine, with reasonable results; using the gamepad for mount control and a new wireless link with my tablet computer, I can also make focus and alignment adjustments at the mount without returning to the computer each time.

As a result I have dispersed with the SynScan handset for alignment and can now completely set-up and control imaging with the computer and tablet; this is nothing short of a revolution which I am hopeful will greatly increase set-up time as well as improving control and tracking accuracy – yipee! Even with average guiding results I am now achieving good exposures of 5-minutes or more and therefore decided to put this success to work and re-image some winter wonders over three, yes three, consecutive nights at the end of November.

Imaging targets between 28th & 30th of November 2016 – for descriptions & previous images taken of these objects click on the following list of names: (1) M45 Pleiades (2) Barnard 33 The Horsehead Nebula & NGC 2024 Flame Nebula (3) M42 Orion Nebula (4) NGC 2244 Rosette Nebula (5) NGC 1499 California Nebula (6) IC 405 Flaming Star Nebula

The night sky at this time of the year contains many of my favourite objects, but surprisingly I had not imaged some of the chosen targets for more than a year or two and it was both enjoyable and pleasing to reacquaint myself again. With a new perspective gained from this exercise, the progress I have made with equipment and techniques is more apparent. Notwithstanding, it’s time to move on – everything’s relative.

M45 Pleiades, Taurus constellation: 12 x 300 sec @ ISO 800 | 28th November 2016

NGC 2014 Flame Nebula & Barnard 33 Horsehead Nebula, Orion constellation: 15 x 300 sec @ ISO 800 | 28th November 2016

M42 Orion Nebula & M43 De Mairan’s Nebula, Orion constellation: 2 x 300 sec @ ISO 800 | 28th November 2016

NGC 2244 Rosette Nebula, Perseus arm of Milky Way, Monoceros region: 21 x 300 sec @ ISO 800 | 29th November 2016

California Nebula, Perseus constellation: 12 x 300 sec @ ISO 800 | 30th November 2016

IC 405 & 410 nebulae: 15 x 300 @ ISO 800 | 30th November 2016

Notes: all images taken using a William Optics GT81 refractor telescope + PHD2 guiding + modded Canon 550D DSLR & x0.80 field flattner @ ISO 800 with full darks + bias + flats calibration and processed in Deep Sky Stacker & Photoshop CS2