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Old 04-06-2016, 01:28 AM
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Shiraz (Ray)
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Join Date: Apr 2010
Location: ardrossan south australia
Posts: 4,918
hot off the press - finally got some sky between the clouds. M83 from 84x1minute subs at gain100 and -15C. Have not yet done any sort of calibration and the setup I was using did not support dither, so the low noise of the camera was advantageous. Processing was alignment, stack, deconvolution based on measured PSF, histogram stretch, very mild noise reduction and a crop to select the most evenly illuminated region. Seeing was average and the EQ8 was only managing about 0.9arcsec RMS in the conditions. Transparency was also nothing better than average. I also have some 30 second subs and they look OK as well - haven't used them yet. The galaxy was also readily visible in 5 second focusing images.

http://astrob.in/full/251238/0/?real=&mod=None

overall, the camera worked well. I was babysitting it to see if any issues arose and caught myself regularly saying B*** heck under the breath as the low noise images poured out. No odd behaviour and there was no sign of fan vibration - also seems that 1.25 filters will be usable, but that decision will await some flat data. Will process it properly at some stage, but wanted to get something up on IIS asap. The attached small image shows the core with a more mild stretch - at 1 minute it was just under saturation levels. The theory works .

So, FWIW, based on Glen's and my images to date, looks to me like:
the camera is very low noise - there is very little dark current, fixed pattern or read noise and there is no issue with "amp glow"
there is no problem with fan vibration
the low read noise really does allow very short subs without loss of final SNR
the effective dynamic range is excellent with a little care
Regards Ray
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Last edited by Shiraz; 04-06-2016 at 07:20 AM.
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