g3 16200 Dark Frame

[Sniperman42]

I have recently purchased a Moravian G3 16200 camera used online, and I don't know if the dark frame taken on it is normal if anyone with knowledge could take a look let me know your thoughts.

2021-11-29_17-44-26__17.72_12.00s_0001.fits

[DaveS]

I don't see those dark borders in my Dark frames, but that may be down to the software. I also don't see the bright top to the frame or the bright vertical lines.

I see from the FITS header that you captured at ambient temperature, what does it look like at the set point, -26 degrees?

For reference, here is a stack of 300 sec darks from my camera at -25 degrees, captured in maxim with the Moravian driver.

I make no claim as to the perfection or otherwise of my Dark frame, but the camera was bought new.

[Oddsocks]

There are two issue with your dark frame:

The dark current looks normal, assuming as DaveS point out above the temperature discrepancy in the image FITS header, where the set temperature is recorded as -26 deg C. but the actual CCD temperature reported is ambient, +17.7 deg C. It appears that the CCD cooler is not switched on in N.I.N.A, or the camera cooler is not running for some reason (low supply voltage auto switch-off protection for example, or something else?), and this is reflected in the dark current values.

The other issue is that the image size is incorrect, according to Moravian the active sensor size should be 4524x3624 for the g3-16200:

https://www.gxccd.com/art?id=366&lang=409

This is different from the active sensor size as detailed in the OnSemi data sheet for the KAF-16200 sensor = 4500x3600 (see linked data sheet below)

https://www.onsemi.com/download/data-sheet/pdf/kaf-16200-d.pdf

It appears that Moravian by default include a little of the unused sensor overscan dark region in their camera specification as well as the normally unused blue-only bayer filter at the edge of the bayer array in the colour sensor version KAF-16200C.

Your dark frame however is showing a sensor size of 4630x3694 and is displaying the normally hidden overscan, test and buffer regions at the top, bottom and side edges of the sensor (see page 3 of the linked OnSemi data-sheet above).

Overscan regions may be switched on-off in the camera driver and may also be accessible directly from the capture application (N.I.N.A.?).

Except for special imaging techniques the overscan regions of the sensor should not be captured and should normally be deselected in the camera driver or the capture application where these are user selectable. I don't use N.I.N.A. and can't advise how that capture application deals with the overscan regions.

Is this a mono or colour camera?, not that it makes any difference to the sensor array size and overscan regions, which are identical for the mono and colour versions of the KAF-16200 sensor. The FITS header is reporting a colour bayer array present and is a colour camera.

HTH

William.

[DaveS]

The OP hasn't been back since early yesterday, has he lost interest?