Leo Trio Plus???

[petevasey]

The Leo Trio is of course well known and a favourite target.  But the tail of stars spreading East from NGC3628 is on a different level altogether.  I've always wanted to capture it - there are some beautiful images around.  But I suspect the vast majority were taken under very dark clean skies.  As we know the UK weather this Spring has been dreadful - wet and cloudy almost all the time.  But a clear sky was forecast for 30th March even here in North East England.  The Moon became obtrusive by 3 am on 31st, but I managed to collect 17 Luminance and 6 each RGB subs, all 10 minutes, binned 2x2 with my QSI683 camera on my TMB 105 refractor (650 mm fl) .  Here are the results.  The reasonably processed 'Galaxies' image isn't too bad, also showing quite a few tiny background galaxies.  But the highly stretched version although it does show the 'tail' also shows just how poor the conditions were with turbulence and huge amounts of background noise from general thin haze and sky glow.    I don't think I've had a single night this season with steady transparent Arctic air.  Sometimes I wonder if it's worth continuing imaging the way the weather is going,  particularly when I look at an image I took of NGC3628 in 2010.  Maybe more data will help to reduce the noise, but the forecast for the next week or so is also rubbish, and before we know it the twilight nights will be here.  Ah me, what a world!

Cheers, Peter

[ollypenrice]

With modern processing tools, Peter, you could incorporate a very significant part of that wonderful tidal tail (second image) into the nicely stretched galaxies of the first image. At least, so I believe.

This is particularly true since the second image is superbly flattened and free from gradients.

Olly

[petevasey]

Thanks for your interest, Olly.    I've had a good play with the image.  Certainly I can improve it to look less noisy overall, but in doing so the tail tends to disappear into the background - it's simply not contrasty enough.    I just hope for better conditions this month.  Last chance for this target under dark skies at my latitude.

Cheers, Peter

Edited April 3 by petevasey

[WolfieGlos]

Another Leo Trio, well done, and the tail is a pain right? 

2 hours ago, petevasey said:

Certainly I can improve it to look less noisy overall, but in doing so the tail tends to disappear into the background - it's simply not contrasty enough

I found exactly the same, mine looks very similar to yours in the stretched version but any form of NR just kills it off.

[ollypenrice]

7 hours ago, petevasey said:

Thanks for your interest, Olly.    I've had a good play with the image.  Certainly I can improve it to look less noisy overall, but in doing so the tail tends to disappear into the background - it's simply not contrasty enough.    I just hope for better conditions this month.  Last chance for this target under dark skies at my latitude.

Cheers, Peter

 

4 hours ago, WolfieGlos said:

Another Leo Trio, well done, and the tail is a pain right? 

I found exactly the same, mine looks very similar to yours in the stretched version but any form of NR just kills it off.

Have you tried Noise Xterminator? It's what I use to control the ultra-highly stretched regions in our images over the last year or two. It removes only the noise.

In order to find out what's lurking, unseen, in my initially stretched data I run it through Photoshop's Equalize routine (in Image-Adjustments.) This is a diagnostic filter but it tells me what's in there and, once I know it's there, I'll move heaven and earth to get it into the final image.

Olly

[petevasey]

Hi, Olly,

Unfortunately I can't use NoiseXterminator, or for that matter StarXterminator.  I've downloaded trial versions of both, but the plugins are not 'seen' by my Photoshop version (CS3) .  It's not shown as supported, but it was worth a try.   Unfortunately  I'd need CS4 at the least, and of course although that is shown for sale on some sites, I don't know if it's worth it - probably not.  I certainly don't intend to take out a yearly subscription for the current version.  I can't even install Affinity Photo - my Windows 7 is also too old!  But I do have an earlier version of GradientXterminator which indeed I did use on this image and it worked well as you noticed.  I also have a program called Neat Image, available both as a stand alone and PS plugin which works quite well to reduce noise in a controlled manner, although it's not in any way AI.  Fortunately Starnet++ 2 does run on my machine and I've used it successfully on a number of occasions, so don't miss StarXterminator.

In general the tools I do have work well.  It's just in extreme situations like this that the very latest clever software might be of assistance.

Cheers, Peter

PS.  Added later.   I've found that StarXterminator and NoiseXterminator won't work in Windows7 anyway.  So to use them I'd need to upgrade Windows and buy PS CS4.  I don't think so!  Although W7 is no longer supported by Microsoft I find it very reliable, and it runs all my equipment without problems.  As does my Observatory XP computer!  If it ain't broke, don't fix it 😉 

Edited April 4 by petevasey
Added PS

[petevasey]

A decently clear night last night (7th April), and although windy the shelter of my Obsy dome and the high speed Starlite Xpress guider took care of that.  So I was able to capture another 16 luminance subs, so a total of 33 x 10 minutes binned 2x2.  I also got a bit more colour data, but have stayed with the original which for some reason came out better with minor tweaks.  So at last I can just show the tail without too much noise. Full size result below.   That's that for the tail in my muzzy UK sky.  Not the best of the Trio, but they would be better with my longer focal length SharpStar 140.  Or even a mosaic with the 2 metre RC10 to really grab the galaxy details.  Maybe next year 😉

Cheers,

Peter