I suspect that they do, but is it really less than what appears on the ASI 174MM/MC?
ZWO says that the ASI 174 is somewhat unique in the amount of banding or fixed pattern noise it produces because (perhaps) it uses Sony's relatively new Pregius global shutter technology. However, I've seen comments that suggest that the other CMOS cameras from ZWO also have similar noise problems.
I downloaded the sample DF that ZWO offers on the ASI 178MM-Cool product page but that seems to be from an ASI 174MM rather than the suggested 178MM (the link just says: "Here is a 60s long exposure dark file of this Camera"). However, the FITs header says the camera resolution is 1936 x 1216 and the pixel size is 5.86um which is what the ASI 174MM has, not the 178MM.
So, is there anyone using the ASI 178MM that can comment on the banding and fixed pattern noise that they see in their subs? Best case would be someone who actually has one of the new ASI 178MM-Cool cameras. A simple, stretched sample from a short exposure DF would be fine.
In any case, here are two sample DFs from an uncooled ASI 174MM, one at a 1 second exposure time and another with a 16 second exposure (these are both stretched, in the linear mode all you will see is some hot pixel artifacts). These have also been sized reduced and compressed to meet the size restrictions on CN (size reduction from 1936 x 1216 to 1600 x 1005). Top (or first) image is 1s, next is 16s.
The air temperature at the time the 1s DFs were captured was 38F (I have no record of the internal camera temperature because Sequence Generator Pro doesn't report the camera temps for the ZWO ASI174). The air temperature for the 16s DFs was 37F. The gain settings for both was 179 (unity gain, or the H-gain setting in the ZWO drivers).
Edited by james7ca, 06 January 2016 - 05:48 AM.