ollypenrice

Like you, I'm knocked out by this combination. Interesting that you're at 100 gain. We've yet to try that. Olly

A lovely image which reaches the holy grail of being packed with fine detail without looking sharpened. Olly

Yes, that's a good test! I need bigger pixels. Olly

Taking a set of exposures and stacking them would certainly let you process more aggressively but the stack would, of course, have blurred terrestrial features - trees and horizon. This can be fixed by using Layers to replace the stacked lower part with a single shot. There is a great deal that can be done in astronomy software to reduce light pollution. If you posted a link to the original RAW data (via Dropbox, for example) we could see what can be teased out of it. Many UK imagers of deep sky objects begin with an entirely orange image - but a good picture can still be found within that. Olly

Should be ideal. 3D printers are just science fiction where I live... Olly

Very good! How are you going to stop lateral movement of the camera as you rotate it? Let us know how you get on untangling the reflections! Olly

I very much like imaging at a pixel scale similar to yours, in my case about 0.9"PP. I find I can present images at full size and be happy with how they look. Ironically, perhaps, I find I use this high res setup to do single panel images which I often then crop to post areas of interest at full size. I also run a widefield rig at much lower resolution (3.5"PP) and I usually make mosaics with that one. So my small field images get smaller and my widefields get wider... It just seems to work out that way. Be aware, though, that aiming to post at full size means taking plenty of exposures and you need a guide RMS no more than half your image scale. 0.9"PP gives me results like this: https://www.astrobin.com/full/miqpyu/0/?mod=&real= https://www.astrobin.com/full/335042/0/ https://www.astrobin.com/full/393219/0/ https://www.astrobin.com/full/419975/0/ I've imaged at higher resolution but not found that it gave better results so I stick at 0.9 by personal preference. Olly

Stephan's Quintet also has an interesting history in astrophysics as one of Halton Arp's contoroversies... Olly

Thanks Ciarán. (I had to copy and paste to get the accent! 😁) I'll see if I can give this a try. We do have APP but I haven't yet tried it. Olly

That's very convincing indeed! Olly

The advantage of the Newtonian reflector is that it provides large aperture at low price. And the advantage of the Dobsonian mount for Newtonian reflectors is that it provides simplicity of setup, stability and intuitive movement at a low price. On a budget, that pretty well knocks the alternatives out of court... but, of course, there are caveats. Larger aperture means larger scope and Newtionian reflectors do need collimating, but this is not normally difficult. Can you get to an astronomical society to see these things in the flesh and possibly try them? A list of societies affiliated to the Federation of Astronomical Societies appears here: https://fedastro.org.uk/fas/members/members-location-by-county/ Olly

An excellent process and an excellent explanation of it, beginning with the principles and moving on to the application. It is very rare in the IT world to find decent explanations! Many thanks, Wim. Olly

But this is of no consolation if you've bought equipment intending to bin and find that you can't do so... Olly

I don't think we can assume that binning will 'just work.' I've had two CCD cameras on which it produced too many artifacts to be of any use at all and others on which it worked perfectly. This includes two cameras of the same make and model. I'm also finding with a CMOS camera (ASI 2600) that software binning in AstroArt is giving me poor stars on which the colours are not properly mixed. I get different coloured stellar edges from one side to the other. Perhaps other software will work better but I mention it as a 'problem in progress' which we're still exploring. Olly

I agree with Vlaiv and like the overall colour balance with the blues set lower than is usual. I think the background is, indeed, a bit 'busy' and the red field stars are shouting a bit but that could easily be tamed in any program with layers. I really do like this one. It somehow has an 'old and far away' look which is great. Olly

Great field! That was a 6-panel in the FSQ106/Full frame setup. Olly

Lovely, Peter. Another voter for V2. Olly

You're right, what a great object - and you've done it proud. Olly

Using a pure log stretch of the stack for reference I've tried to correct the contrast artifacts around bright stars and groups of stars. Thanks to @peter shah for picking this up. Olly

You've mentioned MMT before but I'd forgotten. I'll look it up. I only ever use LHE-modified images as a layer in Photoshop, so very selectively. (This kind of shameless promiscuity makes me fear a visit from the Spanish Inquisition who, as is well known, lie behind Pïxinsight...) 😁lly

I think it comes from local contrast enhancement. I used three methods to get more structure out of the dust. 1) Noel's Actions applied only in Blend Mode Darken. 2) Application of a greyscale equalized and blurred image copy as a layer mask. 3) Local Histogram Equalization in PI. I think that 1 and 3 always run the risk of darkening the areas around stars. However, most renditions of this target do have large stars and I wanted to see if I could have small ones. Olly

I didn't remove stars this time, Peter. I don't think my PC will do it on these images. Starnet keels over. The effect is real, though, and probably arises from various tricks for enhancing local contrast. I've done some fixing already but clearly not enough! Olly

Here's a more pushy version, still trying to keep the stars down. It's interesting just how different it is processing RASA data as compared with refractor. Olly

No, I hadn't seen that, so thanks. Olly

Yes, mine's rather a conservative rendition. I'll see what I can find. I was rather focused on the stars, I suspect. Olly