Discussion - The Vera Rubin Telescope

 A good summary read. How exciting is this? 

BBC News - First celestial image unveiled from revolutionary telescope https://www.bbc.com/news/articles/cj3rmjjgx6xo

https://www.cbsnews.com/news/largest-telescope-first-images-galaxies-vera-rubin-observatory/?linkId=833984765&fbclid=IwZXh0bgNhZW0CMTEAAR5omx4KR85xv0I7D-6uPGS6lksbqmeFuNIPara-2hDcyhxA-d6I3dqKD6vGyA_aem_ucz_jA7erJhtxuO1xQcJVQ

https://www.skyatnightmagazine.com/news/vera-c-rubin-observatory-first-images?fbclid=IwY2xjawLKZ0xleHRuA2FlbQIxMQABHmMraVtOyClhsZ8MBtM5cxEve1Su-fkFQhH91i1sJwGNKiCY-lbWcEksD2wE_aem_Abkwu5lImoNKq3uTaR4RUw

Editing tutorial - Further post editing of NGC 7000 The North American Nebula

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 A few nights ago I managed to image NGC 7000 The North American Nebula and I was very pleased with the results. This post documents the night and my first image. 

https://undersouthwestskies.blogspot.com/2025/06/imaging-ngc-7000-and-ic-5070-using.html

A day or two later and I have had another go at post editing and this is the resultant image. 

And here below is the original 'first effort' post editing of the data from a few days ago. 

Quite a difference isn't it. I have managed to regain some of the nebula detail particularly in the areas I'd originally blown out. I think there is better definition an structure to some of the key features as well. 

On the negative side - the colour balance still isn't right is it? I think it should be a deeper red colour but maybe I'm wrong on that?  

Anyway, in the spirit of being a lifelong learner, please give me some feedback. It will help me and other beginners who visit these pages. All constructive criticism is welcome in the comment box at the end of the post and thanks for taking the time to give me and others useful feedback. Appreciated. 

So what were the editing programs I used second time around? 

• SIRIL V1.2.6
• Affinity Photo
• Photoscape X

I followed the following video I found on YouTube - 

How did I change my normal post editing workflow this time round? 

You can read about my normal post editing workflow in a past post - here: https://undersouthwestskies.blogspot.com/2025/01/a-beginners-guide-to-using-siril-some.html

This time around there were a few changes to what I do: 

• I didn't use GraXpert
• No deconvolution (not sure about this one - but I religiously followed the video) 
• Workflow was all done in SIRIL as follows: 
• Crop and rotation
• Background extraction - and playing around with parameters more; did it twice
• right hand mouse click and 'aberrations' to take a close look at the stars 
• Colour calibration to get background neutralisation and also accurate 'whites'
• Photometric colour calibration - ensuring focal length was more accurate - reflecting that I was using 135mm lens on APS-C crop sensor DSLR
• General Hyperbolic stretch - using modified arcsinh in linear mode. I had drawn a tiny square on an area of dark background sky (when zoomed into the image). Used eye dropper to set symmetry point and then moved the middle and right hand side slider triangles about; also applied some highlights protection as well.  Repeated GHS x 3
• Colour saturation adjustments - repeated for just cyan-blue adjustment as well 
• Cosmetic correction applied
• Starnet applied but with 'pre-stretch' box unticked
• On starless image in linear mode - Histogram transformation  - just red channel - a few subtle repeat adjustments
• then HTF on all colours
• Colour saturation adjustments 
• another GHS on 'even weighted luminance' mode
• Close starless image and open starmask image
• Green noise reduction 
• Colour saturation adjustments - reduced slightly; repeated, reducing pink-red colouration slightly
• Histogram Transformation - reducing stars by moving middle and right hand slider triangles
• close starmask and re-open starless image
• complete background extraction on this image - ensure no red squares are on nebulosity areas; increase samples line slider; add dither - switch between compute background image and 'original' image to see changes
• Histogram transformation - adjust red and repeat - small iterations
• Star recomposition  - GHS - select black point in menu - make small adjustments 
• recrop to preference
• GHS - on all colours - use symmetry point based on square in area of dark background within nebula area
• colour saturation adjustments - first on global; then repeat for  pink-red and then again for cyan-blue
• Histogram Transformation minor adjustments
• SAVE as TIFF and open Affinity Photo 

In Affinity Photo: 

• in Camera RAW 'develop' persona - adjustments to basic elements (exposure, white balance, saturation, vibrance, contrast, brightness etc
• back to camera editor - denoising, sharpening, level adjustments 
• EXPORT as PNG

In Photoscape X

• Film - find overlay that best adjusts final image and apply
• Insert text and logos
• SAVE as PNG

I learned much more about how to do GHS and use color saturation from the above video.  I will try doing this again but next time including GraXpert and also Deconvolution in SIRIL 

Discussion - Has technology made me lose sight of the awe and wonder of the night sky?

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 With blocked horizons to my south and west, an incoming cloud bank from the south west, a limited viewing time slot, a rare clear night for three hours and the light pollution from my neighbour's kitchen light which is left on all night, I was feeling highly pressured the other night! 

I'd spent much of the day, as for most potential night observation sessions, glued to my phone - checking photopills, google maps, clear skies, sky safari plus, astrobin and the met office weather forecast. Where to go? What to see and image? What had others done on Astrobin? Plans, more plans, rewritten plans. Most times I enjoy this process but when there have been very few nights thus far this year where skies have been relatively clear, this first one for weeks - well it was causing me stress. FOMO type stress! 

As it was, the forecasts began to worsen and so I gave up planning a trip somewhere. Another crushing disappointment! But, lo and behold, the skies above my house began to clear around 9pm; a direct defiance of the weather forecast apps. Would it clear? Was there a chance that I could just.........

..... set up and sneak out into the garden for a short three hour astrophotography session based on whatever I could see in the skies above my garden?  Wow.....opportunistic! All that planning about to be chucked out the window! I felt quite 'devilish and rebellious' I must say!  No packing the car, gathering appropriate clothing and packing flask and snacks.  Just everything set up by 10pm waiting for darkness to fall. Stress free - literally moving equipment from study to garden. Simple! Wonderful! 

I think I have become 'captivated by technology'. A slave to it and too geeky by far. And that's saying something as I have always been geeky! In the last year I have set up autoguiding on my basic rig, got to grips with the ASIair app and then more recently become obsessed with getting my donated EQM-35-Pro to work with all my 'gear'. And let's not get started on my obsession with mastering every post editing astrophotography programme there is! 

Has this desire to get it all working and the pressure to make the best of every limited observation opportunity made me lose sight of something more important? Have I lost sight of the joy, awe and wonder at just pausing, stopping and staring at the night sky above me? For no other reason than to just appreciate its sheer beauty and immensity? 

The privilege of being able to just walk out and set up in your back garden at a moments notice should not be underestimated nor under appreciated. By 11.30pm I had started my imaging session of NGC 7000 above me in the NE sky. For two and a half hours after, I just sat on my new bench below my kitchen window and stared at the sky above whilst my 'technology' went about its little workflow plan. 

At first I tried to trace out the constellations above me but I soon gave up. Why? Because I had forgotten them. Now I never was good at remembering them in the first place but actually I couldn't name one. And I am sure a couple of years ago I could. So what has happened?  So obsessed with getting it all working, getting it all framed correctly, getting the guiding so precise...... did I lose sight of the point of being out there in the first place? To learn new things and to appreciate the cosmos above me? 

I have been privileged to have walked under the extraordinary skies of the Serengeti, the Namibian deserts, and the river estuaries of The Gambia. I've wandered the salt flats of Death Valley under the stars; clambered across the red rocks of Capitol Reef National Park and viewed the stars from the high alps and Kilimanjaro. I can remember that intense feeling of complete awe and wonder; of feeling both infinitely small and inconsequential and yet, simultaneously feeling so unique - the only one of ME - in the entire universe. (Unless of course there are actually parallel dimensions, in which case...... )

I gave up tracing constellations and focused on some star hopping instead where I made better progress. Almach to Mirach to Andromeda. Bingo. Deneb to Sadr to Crescent nebula. Result. Down to the Western Veil Nebula.  Getting better! And then, I realised something immense. I was missing the point of being out there. Star hopping was utilitarian. I knew it because it was an ends to a means - finding a DSO to image. 

I breathed in, slowed my breathing, kept staring up at the sky above and relaxed. A zen moment of mind clearance and slowly my mind started to wander. The bump of a snail falling off the ivy onto the decking. The scurrying of tiny feet across the top of the cushion box - Caligula, our resident rat was on nocturnal prowl. The grunting and snuffles of Hermione our hedgehog as it discovered slugs in the pea patch. The hoot of Ollie our woodland tawny owl; the rustling of ivy outside the kitchen door in the gentle warm night breeze. 

Above me twinkling Vega and despite living in a bortle 5 area, the moon hadn't risen and so an hour in my eyes had become accustomed to the dark; the night sky above began to take on the appearance of a black velvet table cloth over which some uncouth diner had spilt some salt - scattered grains bright against the fabric. 

Tranquility descended. No more expectations and pressure to keep checking the histogram. No jumping up to see that the cabling wasn't snagging. No trying to star hop. No feeling the need to 'absolutely learn and master' the constellation positions. Just me looking up from my comfy bench, sat on my comfy cushion, appreciating the awe and majesty of the vast cosmos above me. 

And questions...... of course I had questions...... my brain can't stop asking questions.... it never rests.... 

...... does space actually end?

...... are there really multiple universes?

...... are we really the only ones out here?

...... is there really a theory of everything?

...... NGC 7000 existed 2500 light years ago and I'm imaging it now - but....is it still there? Has it actually dispersed? 

And of course most importantly ..... is transwarp travel actually theoretically possible? And if so, when? 

I really enjoyed not dashing out to the coast or up onto Dartmoor for a change! Garden astrophotography. What a revelation! 

Imaging session - NGC 7000 and IC 5070 using Optolong L-eNhance EOS clip in filter

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I have bitten the bullet and gone ahead with the purchase of an EOS Optolong L-enHance clip in filter for my DSLR. This was against advice from people at various astronomy retail outlets and also on various Facebook forums. Essentially, they felt I should wait until I upgraded my image train to a specific astro cam and filter wheel arrangement and then go for the Optolong L-eXtreme or some such other filter. 

But, I can't afford to upgrade my image train at the moment, nor for the foreseeable future and anyway, I like imaging with my DSLR. 😕

Recently, finding a cloudless night has been about as rare as finding golden hen's teeth. But one did occur a few nights ago and so I went out into the back garden for an imaging session. 

Now I was facing some constraints!

• a 60% waning moon rising at 1 am
• my first try at using a clip in filter with my newly astro-modded DSLR
• a limited sky view - I can only image from NW to NE skies from my garden; or directly overhead towards the zenith. The steep hilly garden to the south with its tall woodland trees block southern sky views. 

I decided to try for an emission nebula - NGC 7000, The North American Nebula. I've given details further down the post. A bonus would be capturing IC 5070, The Pelican Nebula. 

Wanting a widefield view and after my disaster missing Rho Ophiuchi last session (because I used my Zenithstar 61ii), I opted for my samyang 135mm lens. So, equipment on the night was as follows: 

• Samyang 135 mm lens
• Canon 800D astro-modded DSLR
• Optolong L-eNhance clip in filter 
• Skywatcher EQM-35-Pro mount
• ASIair mini
• RVO 32mm F/4 guide scope with ZWO 120mm mini camera
• Red dot finder scope 
• Celestron Lithium Pro battery pack 
• Two dew heater straps
• Two power banks 
• Skywatcher right angled Polar viewer and MSM green pen laser 

So here is the night's images - the same image - wide view and cropped in. Shooting details shown between the images. Remember that Blogger has a 100mb upload capacity and so I have had to reduce the quality of the images somewhat to get them to load up to this post. 

Shooting details: ISO 1600, F/2.8, 300" x 25 with 10 of each calibration frame

Post editing details: Stacked in Siril; background extraction and denoise in GraXpert; colour calibration, deconvolution in Siril; finishing stretches, sharpening and colour balancing etc in Affinity Photo

So, two questions - how did the night set up go; and, how did the post editing workflow progress? 

The night went smoothly. Actually one of the smoothest night set-ups I have had.  From getting out the tripod to finally shooting on the target took just 40 minutes; not my normal 60 or so! Result! 

I was worried that using the clip in filter would cause me some focusing issues but I whacked ISO to 12,600 and then found the brightest star I could find in the sky. Using Live View and my zoom in buttons, I was able to see the star clearly and get sharp focusing straight away. I used a strip of masking tape to then secure the focus position on the lens. 

Because I couldn't see Polaris (due to scaffolding up the side of the house - recent huge flat roof leak - long story - let's not go there 😱) I had to rely on 'All sky align' mode on the ASIair mini. It worked perfectly! Five minute long exposures are the longest I have ever done and BIG result? Guiding was spot on perfect, most of the night it was below 1.0. Seriously, on a stiff to balance EQM-35-Pro - amazing! 

Time spent a few weeks ago working on my imaging train also paid off. I have sorted my cabling and arranged it so that surplus cables are bundled neatly and stored on the imaging rig - reducing the cable rig weight. My son-in-law kindly 3D printed off some tripod powerbank holder clips which helped as well. I will do another post about this at a later date. 

Upshot? I managed to image for around 2 and 1/4 hrs before clouds started to close in. Ideally I would like to try and get three hours worth of images. Maybe I will try and add more images on the clear night - although I am also being tugged by the desire to go off and get some milky way landscape images! 

I am, in all truthfulness, always pleasantly surprised when I manage to get the ASIair working as it should. Initially, things didn't look very promising but then things settled down. 

Ok, what about post editing then?

I am still using Siril version 1.2.6.  I know there is a new, really whoopy new version out but I haven't bothered to download it yet because I am still trying to understand the basics on this simpler version. Small steps and learning to walk before you run and all that! 

However, I am really pleased with these images. The full resolution ones show marked improvements in my post editing skills? So why the sudden leap forward? Well, I have managed to better understand GHS stretches in Siril. I have altered my workflow slightly to do more stretching in affinity photo as well. I better understand how to reduce star intensity and luminosity using JR Ritson Macros for affinity photo (thanks James). For the first time, one of my DSO photos has some 3D depth and structure to it. 

At long last! 

I know there are still many issues not addressed - especially colour saturation and blowing out some of the detail in core areas - but small steps as I said before. I am a 'slow' learner. Persistent, curious, determined, resilient - but 'slow'! 😁😂

So, what about the filter? 

A game changer in my view. Wow. Noticeable effect immediately from my bortle 5 back garden. I won't bother doing a review of the filter as there are many already on the net - try these if you are interested: 

https://astrobackyard.com/optolong-l-enhance-filter/

What are my initial impressions? 

It is easy to insert. The springy arms on the clip can be adjusted, and unlike my optolong L-pro, this filter doesn't fall out as soon as you move the camera! It seems to work well with an astro-modded DSLR. I used auto white balance for a change and got no odd colour casts. However, I need to play about with colour balance in the DSLR and see what happens on future imaging sessions. I think for the first time, I have gained some good contrast and colour saturation in one of my images. It certainly reduced the normal light pollution colour casts that I normally get. I read on many forums that if I was going to use it, longer exposures was the way to go with some people recommending between 5 - 8 minutes each. Given the longest I have ever imaged before now is three minutes - this is a game changer for me! A Bahtinov mask helps you get really sharp pinpoint stars and focus and of all the calibrations frames, the flats are the most important I suspect as they will correct any vignetting caused by the filter (although I couldn't see any on the finished Siril results image.) 

And finally, what do we need to know about the two images above? 

NGC 7000 The North American Nebula is magnitude +4.00, an emission nebula in the constellation Cygnus and close to the bright star Deneb. The nebula covers an area x10 the size of the full moon and was first discovered by William Herschel in October 1786, from Slough! When light pollution was obviously not an issue! 

It is a huge interstellar cloud of ionised hydrogen and the shape we see from earth is caused by a band of interstellar dust that lies between it and our planet - this dust absorbs the light of stars and the nebula itself and somehow causes this shape to materialise to our vision.  Can tell I'm no astrophysicist can't you! 😁

The portion of the nebula that represents Mexico and central America is known as the Cygnus Wall and is an area of concentrated star formation. 

From us to the nebula is around 2,500 light years. 

So why do we see red? The hydrogen alpha area shine because their hydrogen gas has been ionised by UV radiation from a nearby hot star. For a long time it was thought that this was due to the proximity of Deneb, but not so! Its surface temperature is only 8500K. A star with at least a surface temperature of 35,000K is required. Deneb is not hot enough and too far away from the middle of the nebula complex.

So, where is the UV coming from? There is a star off the 'Florida' coast area of the nebula which may be a contender. It appears small and dim from Earth because it is behind the nebula but it is closer than Deneb and its surface temperature is 40,000K. Ideal! 

And IC 5070 The Pelican Nebula? 

Tricky to discern but I have circled it above. You will need a little imagination here! Early astronomers thought the nebulous gas emissions resembled a pelican! Nope! Me neither but hey there we go! 

Anyway, it is an area of very intense mixed star formation and gas cloud formation and is highly studied by modern astronomers today. Light from energetic young stars are slowly transforming cold gases to hot ones, so causing an ionised front to slowly advance outwards. 

IC 5070 is divided from NGC 7000 by a dark dust molecular cloud area. 

Still can't see the Pelican? Look for a dark dust cloud eye and then a long bill. The bright front of ionised gas curves away forming the head and the neck. 

Nope, me neither! And normally, as a geographer, I am really good at this 'spatial awareness' malarkey! 

Discussion: Lost in Space and Meridian Flips

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 Astrophotography is a funny old game isn't it. Take last night. Target IC 4604 - The Rho Ophiuchi complex. 

My best ever polar alignment and set up times. A clear sky, faint breeze and a 37% moon. The tide almost in and breaking over the rocky foreshore below the car park. The distant rhythmic flash of the Eddystone Lighthouse and far out in the English Channel, lit up ships passing in the night. 

ISO 800, 240" x 20 plus calibration frames. My little radio tuned to Radio Four and then The World Service. My primus stove hissing and bubbling away away when I felt the need for a warming cuppa. 

Astrophotography and astronomy have taught me much over the last few years about the night sky, how to use my cameras, mounts and telescopes/lenses; and of course imaging techniques. A newly found passion for astronomy, astrophotography and art! And all the time, I have been developing my scientific knowledge, use of technology and problem solving thinking. My son-in-law has even ignited within me an interest in 3D printing and the potential it has for creating little helpful bits and pieces for my various astronomy/astrophotography rigs. 

As a person, I have developed more. My patience is much better! My concentration and focus back to pre-retirement levels! And my blood pressure? So much lower! Out at night, under the stars, I am relaxed, pondering, reflecting, asking some big questions, just tuning in to a radio programme I wouldn't have likely heard had I not been up at that hour! 

My friends would say that I've become even more nerdier than I was and that isn't a bad thing at all. I can chatter away about the night sky forever! 

But then it isn't all rosey is it! 

I keep 'hitting a wall!'

One wall is using SIRIL and Generalised Hyperbolic Stretches. I have watched all the Youtube videos. I've taken notes. I have practised and practised - to no avail. I am still none the wiser! 

Another 'wall' is using the ASIair plate solving.  

How did I miss Rho Ophiuchi? I mean how? On my screen in plate solving it was clearly identified and central. When I did the sky atlas stuff - it synched correctly. 

But, as you can see, all the bright cloud colours - where are they? I missed my target! By quite some way! Unbelievable! I am laughing about it - serves me right and a lesson learned. Check that I have the right co-ordinates in RA and Dec! 

Plenty of 'cloud and dust' stuff

ISO 800  240" x 20 

20 of each calibration frame

Canon 800D, Zenithstar 61ii with field flattener 61A, EQM-35-Pro mount, ASIair mini, RVO 32mm guide scope with ZWO 120mm mini guide cam, Celestron Lithium Pro battery pack 

Processed in SIRIL, GraXpert and Affinity Photo. 

If you can identify where in space I ended up in this shot, I'd be grateful! 

Conclusion 'Lost in Space' somewhere! 😕😩😆

Meanwhile here is my third 'wall'. How do you perform a meridian flip on the EQM35PRO using an ASIair mini? 

I thought I had the right settings last night and it sort of performed a flip but the cables twisted and wrapped themselves around the mount and so when guiding restarted it was shambolic. I ended up doing a manual meridian flip; after I had unplugged various cables to ASIair mini and my DSLR. That of course meant rebooting everything and doing a new polar alignment. 🙄

It is hard work being a newbie and novice isn't it 😉😆

If your gear hasn't don a meridian flip yet and you are using guiding with an ASIair - here are two helpful videos that explain the process