CCD Imager

I dont know how Meteoblue calculates their FWHM, I tried to find a reference to it, but alas nothing. However, they may not be far off. Nearly 30 years ago, I performed seeing analysis on the majority of clear nights over one year, using an SBIG STV, utilising the DIMM method. Seeing was mostly sub 2.0 arc secs and often less than 1.5, occasionally less than 1.0 This is the raw base seeing, but you then have to add the effects of optical quality, focus, guiding etc that blurs the FWHM, so users usually end up with a much higher FWHM. Over the many years since I measured raw FWHM, I have been working to reduce additional blurring components, Should you manage to own a high quality triplet refractor and a mount that tracks to less than 0.5 arc sec, your resultant images will have a much better FWHM. Most astro Imagers aim for a sampling of 1.0 arc sec/pixel, a good compromise for the majority of users Adrian

Anything over 0.5 arc sec is under-sampled! Seriously, UK skies offer around 1.5 to 2.5 arc secs FWHM and you need to sample at a rate of 3x for optimal sampling. Not only that, if seeing is better than your optical resolution, you have missed out and if you end up over sampling, you can bin in post to suit your taste. And lastly, deconvolution algorithms just love an over sampled image, give Blur XTerminator a decent chance! Adrian

Great image Peter. Isnt it nice to compare with old photos and see how far we have come. I bet if you re-processed the right hand image with todays techniques, you'll improve it no end, not that it is shabby to begin with. Adrian

nice weather coming next week, just in time for the disappearing moon

Short nights and bad weather over this summer, so found this unprocessed data from last year. 12 hours in total thru SHO filters with ASI6200 and SW Esprit 150 Adrian

yep, same sensor! Steve Hale made the camera body here in the UK, but used the same sensor

Now we are reminiscing! I once had a Hale camera with a back illuminated sensor 1024 x 1024 array, 24u pixels and without ABG. Those were the days

10 minutes, but was blooming even when I was framing with a few seconds Adrian

Hi Chris Thanks. Its remarkable you managed to get anything from the UK, excellent result, it only gets 14 degrees above our horizons and could only get about an hour at this time. It really is down in the murk. Yes my image was with M8 overhead, but you have achieved excellent S/N from shooting through the atmospheric muck Adrian

Hi Peter I an excellent object to choose with contrasting objects and colour and of course, well executed processing. Can I ask what field flattener you are using with the scope? I am half thinking of getting another fast Newtonian Adrian

Here is a quick raw to remind you of the days without ABG camera's

I thought it was about time I processed this nebula. In 2004, I visited friends in South Africa on a long family holiday, but managed to hide a G11, Tak SKY90 and ST10 in the hold baggage, I think my wife was too busy with our 5 year old twins at the time In those good old days, we only took short exposures, so total exposure was just under 3 hours, but the Lagoon was riding high over head in fairly dark skies. The ST10 did not have ABG so I was confronted with many bloomed stars and I am not sure how to process in Pixinsight, so used an old version of MaximDL to deal with those. Nonetheless, it was fun processing with modern tools. I have recently completed images of M16 and M17, but the Lagoon is just too low from the UK. Adrian

Thank you for the encouraging comments! Adrian

I am now blessed with a decent southern horizon, so started this project of M16 July 2022. I can only grab 2 hours a night and during permanent twilight in June/July. Over about 12 nights in total, I accumulated 19 hours of photons, an SHO pallete. Taken with an Esprit 150 and ASI 6200. Two views to view, the latter with a 100% crop of the pillars of creation. Adrian

NIce image, the second is much better with a neutral background, was bluish in the first, and more resolution Adrian

Thanks Matt, pleased it stimulated your taste buds! Adrian

A deep image (for me) of the M81/M82 area showing many other features. I processed 25 hours of data in LRGB and Ha. I could have brought out the IFN more, but it was detrimental to the galaxies even with masking, so instead there is more of a subtle glow Taken in rural Beds with an Askar 107 PHQ and ASI 6200 Adrian

Great image Keith, very similar to my recent version. Its a cool group of galaxies to photograph. I see you have the Pegasus rotator, I'll be buying one tomorrow at the PAS. Adrian

Nice image Paul, great vibrant colours. Couldnt help but notice the brighter corners as if flat frames havent quite worked. Pleased to hear someone else still likes Photoshop You cant beat its finesse and real time viewing when processing. Adrian

It is a refreshing change to see a smaller higher resolution object and you have captured it well. Maybe you should offer a challenge to imagers on SGL - planetary nebula!! Watch em struggle with those Adrian

A lot of hard work has paid off handsomely, excellent final result. It reminds me a little of the Finnish guy who did a whole mosaic of the milky way and it only took him 1o years, lol! Adrian

Very impressed with the Askar 107 PHQ, superb resolution for a little 4 inch refractor. This image is around 7 hours luminance and 3 hours RGB taken over 3 nights. I had an issue with the camera rotating (coming loose!) and not noticing, unfortunately. I used the ASI6200 and a good job I had some real estate around the galaxies to crop out the misalignment. Lots of tiny galaxies around and the arc/stream coming off NGC3628. Adrian

Only managed 6 hours on this one, Ha, OIII and S2, but with modern processing techniques, it has processed well and happy I dont need to add extra hours. Taken with an Askar 107 PHQ and ASI6200, image reduced 2x for a manageable size! Adrian

Olly, I have every single raw image from 1992 The good old days with an ST4, lol Ive just started reprocessing the horsehead data I took with you , now 6 years ago! The difference is marked Adrian

Hi Olly Russ Croman has really changed the landscape for astro editing over the last year. Its Star, Noise and recently Blur Xterminators. Wish I had these 20 years ago Adrian