Need some info on ASI1600MM and big Touptek/Altair cameras

[riklaunim]

I have few questions about the Panasonic and IMX294 big DS cameras. First of all - is anyone using Touptek/Rising Cam/Altair cameras with those two sensors? How do they perform and is the software/driver side stable? Do they work with FireCapture aside of ASCOM imaging apps?

As for mono ASI1600 and alike cameras - do you get any pattern when trying to do a flat frame or lunar/solar imaging at very short exposure with high gain? (like 10-20ms with very high gain and then moving it lower)

[Spaceade]

7 hours ago, riklaunim said:

do you get any pattern when trying to do a flat frame or lunar/solar imaging at very short exposure with high gain? (like 10-20ms with very high gain and then moving it lower)

 

Thinking waay back to when I was taking bias frames with my 1600, I definitely got weird artifacts down in the 10ms range. can't remember what the gain was though.

[Adam J]

You need calibration frames to be at least 1s on a ASI1600. Never take bias use dark flats instead. 

[vlaiv]

I do very short flats with ASI1600, but it is at unity gain, and I do have a "strange" pattern.

It is sort of checkerboard pattern of pixel sensitivity, let me find an example:

This is stretched master flat, and you can see both pixel to pixel variations in sensitivity, but also there is obvious pattern of alternating sensitivity in checkerboard manner. These are tiny variations, here is histogram of this region:

I set it to 32 bins, but you can clearly see two peaks with respective bell shape. Note histogram range: max 0.999, min 0.964 so in effect difference between intensities is about 1.6% or so (0.016 if we assume that peaks in this case are at centers of halves of interval).

Regardless of this pattern - my subs calibrate out fine and there is no visible pattern in subs or stacked images. It is just relative sensitivity that changes pixel to pixel and it's probably due to manufacturing process or something like that.