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Karls48
23-12-2012, 12:26 PM
I’m considering purchase of one of those cameras to use with StarAnalyser. It would be used with either 100mm or 80mm f5 achromats. I realise that achromat is not ideal scope for spectroscopy, but that’s all I got at present.
http://www.zwoptical.com/Eng/Cameras/ASI130MM/index.asp
http://www.zwoptical.com/Eng/Cameras/ASI120/index.asp

Which one would be more suitable for use with SA?
ASI120 got newer sensor 75% peak QE and 12bit A/D converter. But it is only 1/3” sensor with 3.75um pixels – so field of view is quite small.
ASI130 uses same sensor as QHY5 and got only 55% QE and 8bit A/D. But it got ½” sensor with 5.2um pixels and decent field of view. I have tried StarAnalyser with QHY5 and was not too happy with it because of excessive noise.
Decisions decisions.

gregbradley
25-12-2012, 07:47 AM
Which one would be more suitable for use with SA?
ASI120 got newer sensor 75% peak QE and 12bit A/D converter. But it is only 1/3” sensor with 3.75um pixels – so field of view is quite small.
ASI130 uses same sensor as QHY5 and got only 55% QE and 8bit A/D. But it got ½” sensor with 5.2um pixels and decent field of view. I have tried StarAnalyser with QHY5 and was not too happy with it because of excessive noise.
Decisions decisions.[/QUOTE]

You're kind of answering your own question there. If the QHY5 was not suitable and this camera uses the same sensor then its likely to not be suitable also. Higher QE is usually more important in astro work, not sure about spectro work.

DMK are not much more and are proven known cameras. I'd suggest you go with one of them rather than a new untried low spec camera that noone knows about. Chances are it will not be good as its too cheap. Also 8 bit and 12 bit A/D. Even DSLRs are 14 bit and about to go 16 bit.
Never heard of that before in astro cams. Look for one with a 16 bit A/D.

I'd also doubt that 75% QE figure. That is BS almost for sure.Small pixels, 75% QE, cheap camera = no way.

Greg.

Karls48
25-12-2012, 11:27 AM
I don’t think that peak QE figure for new sensor MT9M034 is BS. Here is frequency response plot from manufactures website. What I can not find anywhere is full well capacity of that sensor. And I agree with you, given size of the pixels it is going to be rather small number.
The camera will be used only for spectroscopy images with StarAnalyser which is low resolution grating.