Eskimo in colour

Given the effort it took to process this (imaging it was no more difficult than the mono) I don't think I'll be doing it again soon with this setup

Thats a pity Dave. Actually I would love to see more of this kind of shot from your stable! Thats a decent image. Ok colours look a bit 'funky' but as jed says thats a personal preference thingie. Nice detail in there.

Reading your explaination on quirky frames I would suggest one thing. I dont think seeing would play as big a factor as you might think. Remember the oscillations are effectively random and very high frequency. Thus really only the average gets to be recorded on the ccd. Thats why autoguiding works so well as when a star moves a bit the scope should nudge it back before it gets recorded. Seeing artifacts are of a much shorter duration than guiding errors. I would suggest that the other factors you mention, temp, tracking play a much bugger role. No doubt seeing plays a part in what detail you get in HR imaging, but I dont think iut will give you egg shaped stars by itself.

On reflection (no pun), I'll probably give colour imaging another lash - but I'll be prepared for three times the work of a mono image

The funky colours are due to processing and lack of the IR filter. I think really good colour images will only come with a hi res mono imager and a set of RGB filters. The integrated colour imagers are not as good as mono chips, all other things being equal, because of the complexity of the colour chip...

A question on seeing - I hear what you're saying but I can;t help thinking that:

If you start a single 60 second exposure, the seeing is going to probably change in that time (especially in Ireland) - so your 60 second image will record all of those changes whilst it record the photons... Then you repeat that single image say 10 times and stack them. There'll be averaging out in the stacking process, but surely you can't do anything about what each individual 60 sec image has recorded? You'll record 60 secs of a star moving around due to seeing...

eg - for planetary images, you make take 0.1 sec sub frames - in that time period, sure, seeing will affect some subframes and not others. You then throw it into registax and it ditches the rubbish. Hey presto - nice clean stack of 0.1 sub frames, leading to a whopping image.

But for deep sky, surely you can't avoid recording some seeing effects? Hence Mauna Kea for the big boys...

The other factors you mention for sure play their role anda s you say may in fact be bigger overall than the seeing.

Maybe I'm reading you wrong - its late and I'm shattered! I take your point about it unlilely resulting in eggy stars though - it shoudl average out at least as a circle - unless there's somehting weird going on with the atmosphere...

Thanks again for the comments - they're very interesting and I'll try and read this again tomorrow!

Cheers

Dave

On the one-shot colour front, we will soon see.

My SAC10 3.3 should be winging its way to me in the next couple of weeks

Later,

Jed.

Sorry Jed - I was probably a little too dismissive and premature.

My knowledge of how mono and colour CCD's differ is probably not good enough to pass a definitive comment like the one I made - especially as technology continues to bound forward. And it seems as though there's a few new players in the market of astrophotography - competition is always healthy!

I'd be really interested to see what your new SAC10 will do.

Cheers

Dave