Hello,
At this moment I'm just learning how to use the camera...
Acquisitions in TIFF 10/12 bits, slow readout mode, gain=0dB (value=76), exposures 5s, then debayerisation and stacking.
The sky background is substantial here because it's summer soltice, so that smallest detected levels are likely drowned in the background.
The image comes from a severe processing. The stars widening and noise increase definitively come from me. A bit of coma / field tilt appear at one corner because my focuser is not perfectly aligned.
The camera shows absolutely no FPN. There is a slight and homogenous brightness gradient, automatically wiped out, along with possible hot pixels with dark subtraction. I just monitor the stability of the sensor temperature but with such short exposures, the temperature always remains steady during 10mn.
In the stacked image, the high dynamics results in pinpoint stars though low levels are present and show no noise. My aggressive processing shows that details in the nebula are numerous, with good contrast even at low levels; it shows no posterisation effect.
After another tester, this camera brings the opportunity to image deep-sky like planets, that is with short exposures (100ms), hence with a lesser degradation from turbulence, and no precise tracking by the mount.
Sony announced this sensor as their best sensitive CMOS colour sensor:
http://www.sony.net/Products/SC-HP/new_pro/october_2014/imx224_225_e.html
Unfortunately the sky is too bright to decently compare with CCD images or with the ASI120MM.
I think the detectivity is lesser than on my cooled CCD (tests with M57 and M27). But the image from the ASI224 is in colours in one pass, exposures last only some seconds (no precise polar alignment, no accurate tracking, no autoguiding), and the resulting resolution and dynamics are surprising. There was only one dark, no offset, no flat, no need for color calibration in 8 bits and a standardizable color calibration in 12 bits.
I'm waiting for a darker sky at now :(
Nicolas
