CCD choice advice

[baileys2611 (Simon Bailey)]

Hi everyone.

Assuming I get my focus gear sorted soon, I will have some dough for a new CCD. I'm currently using a qhy8 (older) and have liked it.

I'll be using a C9.25 at f6.3 (1400mm focal length) and want something that I can also use in my WOGT81 at f6 (480mm focal length). The C9.25 natively is f10 at 2350mm but the way I see it, using a FOV calculator and "CCD Calculator", anything with a smaller pixel well size than about 6 will get me close to the magic 2.5 arc-second per pixel size on the WOGT81 and I'll be oversampling on the C9.25 to the tune of about .88 arc-seconds per pixel. However, short of getting something that has a pixel well size of 15 micro somethings then I'm going to need two cameras and my budget won't do that for me, so it's the one camera.

So, question is, is it worthwhile looking at a QHY12 (about $3k is my budget for a new CCD) or does anyone else have a better suggestion? I'm a fan of OSC cameras, don't want to go monochrome yet because I'm enjoying the colour experience at the moment.

I'm going cross-eyed looking at all the different statistics, QE, pixel size, chip size, cooling capability and anti-blooming capabilities. Other people's opinions, experience, eyes even would be most welcome.

Thanks
Simon.

[Bassnut (Fred)]

The QHY12 has 5.12 um pixels, thats good for WF. Switching to the other scope is a no brainer. Binning at 2 on the QHY12 gives you effectively some 10um pixel size and less noise. Perfect. BTW 0.88 arcsecs is more preferable than 2.5arcsecs, I dont know why you think the later is "magic"?. Anyway, oversampling is generally not a negative and often better.

[baileys2611 (Simon Bailey)]

Oh yeah! (where's the *slap forehead* smiley) I forgot about binning!

Nice one Fred...

I read about the 2.5 figure from a website I found surfing through topics on IIS. It's a bit old - but was here:

http://www.sctscopes.net/Photo_Basic...cd_camera.html

Might be worthwhile asking if that's actually a realistic aim, given advances in technology and quality.

[peter_4059 (Peter)]

If you bin the QHY I don't think you'll get OSC.

[Bassnut (Fred)]

Originally Posted by peter_4059

If you bin the QHY I don't think you'll get OSC.

OK, yes, it seems OSC cams are mono when binned, no matter, I would think 0.88 arcsec is most excellent anyway, my experience is some 0.8-2 arcsecs is fine and much better than 2.5.

[peter_4059 (Peter)]

Originally Posted by Bassnut

OK, yes, it seems OSC cams are mono when binned, no matter, I would think 0.88 arcsec is most excellent anyway, my experience is some 0.8-2 arcsecs is fine and much better than 2.5.

Fred,

I agree with your views re pixel scale but he'll need a filter wheel to take a colour image with it binned.

Better to just get a mono camera

[baileys2611 (Simon Bailey)]

Thanks for the advice, looks like my initial reading was off a little. Will need to re-calculate based on 0.8 - 2 being reasonable instead of aiming for 2.5

But...even if I went with mono I'd still have the same problem. I have a FW with colour filters, could use it when binning, but I like the idea of being able to take a one-shot colour photo when I can, then if I want to bin I can change the imaging setup and work as if on mono.