m8, m20 and eagle - reprocessed

[jenchris]

I discovered I was processing the tifs wrongly and decided to have another shot at it. They appear to be much better.
Lagoon is only two 2.5 min subs and triffid about 11 - Eagle had about 20 - all in iso 800

[Octane]

You're on the right track, but, I would suggest that your composition needs refinement. For example, is there a reason for M16 being so far to the right?

H

[jenchris]

I tend to put the pics a little high because my camera has a lot of ampglow across the bottom - @iso 800 - it means I can crop if need be - it's alos difficult looking through a viewfinder on a camera that is close to the vertical - and a metre off the deck - so sometimes as in this case, I was left with it a little off centre.
I've only just got the guiding weighed off and am refining a lot of things - composition will be on the list somewhere.
Eventually I may even buy a CCD and do it that way but I'll be getting an EQ6 first.

[multiweb]

I'd get a CCD first. Your guiding doesn't need fixing as it is.

[renormalised]

Your stars look good, no really eggy ones, so I'd agree with Marc. A CCD camera would be a bonus. Given you've got an ACF scope so you can't use a reducer (not any I know of), you want to look for a medium format camera with good sized pixels for use at F10. Nothing too heavy hanging off the rear as you'll have weight problems, then, on the focuser. Then it depends on how deep your pockets are and how much you want to spend.

[jenchris]

mmm, convincing you are...
Good a CCD sounds - what medium format size is?

(I can dangle a participle with the best of them) :rolleyes:

[multiweb]

Get an OSC with a chip the same surface as what you're using now so you'll know you'll get the same field. Only more sensitive and you won't need a filter wheel so the learning curve will be smoother. I'd go with second hand to test the waters like a QHY.

[renormalised]

A QHY8 would be the go...the others have smaller pixel sizes that will not suit imaging at F10. If you were able to reduce the FL to, say F6.3 or so, then the QHY10 or even the QHY12 would be good. The chip size is about the same as a DSLR camera and the pixel size suits the FL, then.

The QHY8 also has a chip about the same size as a DSLR.

A medium format camera is one with a chip around 15-25mm diagonal width and with 4-10MPixels. Many of them have pixel sizes around the 8-13 microns, which is about the size you want for a long focal length scope. The cameras of this size also tend to be smaller than their larger chipped brethren, so they aren't as weighty on the focuser.

An example would be the Atik4000, or the SBIG ST4000XCM. The QHY's fit the bill , also.

[jenchris]

thanks guys