What CCD for GSO RC 10?

[Fellside]

Hi

I have managed to find a second hand GSO RC10c. This is to be modified/upgraded and mounted in a ROR observatory which is around half way through the build.

My question is what CCD would be recommended for this scope. It will be used for imaging Galaxies at f8 or f5.6 when fitted with a reducer. I have a budget of around £1800. I know Mono and F/Wheel is the way to go but there are some very nice images being taken with OSC cameras such as the SXM25C. Thanks Graham

 

[wimvb]

Check pixel size and sensor size. Pixel size determines resolution (arcsecs per pixel), and sensor size determines field of view. For galaxies, I think you definitely should aim for resolution less than 1 arcsec/pixel. Maybe down to 0.7 even. It's probably better to oversample than to undersample, even if your sky conditions aren't always ideal. Exactly how far you should take this, depends very much on your conditions and craftsmanship. (Also consider guiding accuracy.)

[pete_l]

Be aware that focal reducers can dramatically reduce the size of your distortion-free image. You can even find that the maximum size of your image is defined more by the "image circle" of your FR, rather than the size of the sensor in your camera.

The larger the camera sensor, the greater the possibility that the FR won't properly illuminate it all.

[MartinB]

The result of the onward drive to higher pixel counts is that typical pixel size has come down significantly.  This is great for short focal length fracs but they can also work well with longer f/l scopes like yours thanks to binning.  This will effectively double your pixel size whilst reducing your read noise and increasing your dynamic range.  

[Fellside]

Hi

Thanks for your replies.

Thinking about Pixel size, Atik 414EX is ok but the FOV is getting small. SX M25c is ok but its OSC on a fairly slow scope. Top of my list at the moment is the Atik 383L + Mono.This might be a good compromise and will work well with shorter FL scopes.

Martin

Good point about binning. There are an ever increasing number of cameras with higher pixel counts and smaller pixel size.

Graham

[sloz1664]

You could also look at the CMOS cameras which are gaining popularity in the astro imaging camp. Namely, the ZWO ASI1600 cool & the QHY163. There is also the Atik Horizon. I know FLO are advertising a special bundle price for the ZWO1600mm cool/electronic filter wheel & filters under your budgeted price.

https://www.firstlightoptics.com/zwo-cameras/zwo-asi1600mm-pro-usb-3-mono-camera-efwmini-filter-wheel-125-lrgb-filter-bundle.html

Steve

[Sp@ce_d]

I’ve been using the Atik 314L with my RC8 & AP 0.67 at about 1.22”/pix and I’d say the resolution is lacking really at that. I’ve also been wondering about one of the CMOS cameras, but they don’t bin. Well they do, but it’s done in software so I believe you have to up the gain to compensate. So I think a bit more investigation of the pros & cons of those at longer FL might be needed there.