Arp 1

[orionoffelt]

This image was captured over two nights 11/12-04-21

Luminance of 32 x 300 

RGB of 6 x 300 each

all binned 2 x 2

scope Celestron 11" with a f 6.3 FR

camera QHY9m

Bob

[cfpendock]

Nice one, Bob.  A touch of blue on the topside of the stars?  I like these images of far away places.

Chris

[orionoffelt]

Thanks Chris I suspect the touch of blue at the top of the stars was maybe slightly out of focus blue data when processing the RGB I did think I should have refocused in some positions of the sky with the SCT the main mirror does move  during imaging. I was imaging another target last night and I did refocus and those stars were a lot better so maybe that was my problem ?

Bob

 

[cfpendock]

I think you may be right.  I find that blue is more usually more of a problem with a refractor so I was surprised to see your blue from the C11.  The mirror on my C11 is always locked and I use a visual back for imaging (and focussing).  This completely removes any problem of mirror movement.  I cannot afford a focal reducer, so I am actually quite jealous!  Have you tried imaging at f10?  Need to watch out for any wind....

Nevertheless,  you have produced a fine image.

Chris

[orionoffelt]

Thanks Chris for your feed back. I have found in the past that the blue is usually the one with a problem with the Celestron  it just seems to effect the brighter stars. You said that your mirror was able to be locked I thought only the Meade scopes had this facility I would be interested to know how you did it was it a DIY job ? I have imaged at F 10 for a few years now but it is difficult to get he right conditions in the UK that is why at Focal lengths of 1764 mm and 2800 mm with the 11” I now bin all my subs 2 x 2 which seems okay for me.

Bob

[cfpendock]

I think that I have made the error of assuming that all CPC1100 s have mirror locks.  Mine is an Edge, and came fitted with mirror locks.  On my CPC1100 there are three knobs on the rear.  One of these is for focussing.  The other two are mirror locks.   I focus through the visual back, so that I don't need to unlock the mirror during an imaging session.

 

I also bin 2 x 2, and sometimes for RGB even 3 x 3 - otherwise the sampling rates become ridiculous - especially for the UK..  

But to capture the image in your post without mirror locks....Well, I take my hat off to you!  

Chris

[orionoffelt]

Thanks for that Chris I thought I had missed something with the mirror lock I have been imaging with mine for about eleven years now and it is a struggle at times to keep focus but I now watch all the subs coming in and if the stars seem to go out of focus I do a refocus. Where as I have another set up with a 500 mm FL refractor on a 

equatorial Mount and it just runs all night with no need to refocus. But for all the problems with long focal length imaging I do like to have a go at the tiny targets.

Bob