You'd get 10/1 on this old nag.

Very sexy portrait of the celestial GG! You have it beautifully framed - did you crop the original much?

You shot this on the 10" f/4 - was this at prime focus or did you have a barlow or two in there - what is the field of view for your f/4+Atik? Just curious about what I'll get with my set-up... if it ever gets set up!

Congrats!

Phil.

BTW Dave, how would you compare the sensitivity of the Atik16hr vs the 300d?

Thanks,

Michael,

As good as the DSLR is there is no comparison to the ATIK16HR. I don't have any quantitive figures to throw around, (maybe I should do some testing). I would say, purely from experience, that the cumulative benefit of the greater sensitivity of the ICQ285AL CCD and the TEC cooling make the whole package a lot more sensitive than the Canon. The really cool thing of course, is that because to the cooling, very long exposures are possible. What I mean is if you were to draw a graph comparing noise as a function of time, you would see if rise very sharply in the first minute or two and then level off so that that, say for example a 15 minute exposure has no more moise than a 5 minute exposure (and of course a lot more signal). This just doesn't happen with the Canon. I'm seriously considering getting the colour version too for taking RGB frames in one go.

You shot this on the 10" f/4 - was this at prime focus or did you have a barlow or two in there - what is the field of view for your f/4+Atik? Just curious about what I'll get with my set-up... if it ever gets set up!

Phil this was at prime focus, no barlows. I think the coma corrector reduces the effective focal lenght by a tiny amount. There is no cropping in this image. The FOV is 22.5' wide by 30' tall. The setup oversamples a bit at about 1.3" per pixel. You can easily calcuate the FOV of any chip/optical combo with the following simple formula

arcmins = (chip size in mm x 3438) / focal length

Nicely done Dave, one to be very proud of!

Seanie.

:shock: Superb shot Dave, IMO your best I've ever seen, the detail is outstanding!

Keith..

Interesting Dave. Looks like dedicated CCd cameras are the way to go.

I'm currently looking at ccd cameras, trying to find a balance between cost Vs pixel size, ccd chip area, arcsec/pixel ratio, QE, noise, etc.

Ideally, I'd like a camera with a large chip (say, 20mm x 20mm), high QE, low noise and pixel size of about 6-7um. Affording that is another story...
Ideally, I would like one camera to work for both the refractor and the 12". The focal lengths differ by a factor of 6 though. The closest I've seen is the SBIG STL 4020, which is not exactly the kind of thing you'd rush out and buy in the morning.

I heard recently that the canon 300d chip has a peak QE of only about 10%. Don't know how true this is though. Compare that to some of the chips in the new SBIG and FLI cameras which have a QE of >80%, and you can understand there'll be a big difference.

I was reading up on the cheapest SBIG camera, the ST-402. In an 8" f/10, it can apparently capture mag 14 stars with a one second exposure and mag 18 at 60sec! Amazing! QE of this chip is 85%.

I was looking at the ATIK webpage. When trying to compare apples with apples, it gets difficult. Not a massive amount of technical info on the site. Clearly, it's a great camera though.