Questionable Dark Frame

[Anthonyexmouth]

Hi, just re-doing my calibration frames as over the 6 month enforced break something has gone wrong. 

just taking some darks in APT and noticing a smudge/smear pattern in the top left quadrant. Can anyone here with more knowledge take a look at a frame and let me know if these are being captured ok.

Thanks

D_2020-03-25_15-16-13_240s_294mc__Color_G1_OFS22.fit

[vlaiv]

I think you have a light leak.

You should not have such gradient on your dark, and there are hints of dust shadows, although, depending on type of light leak - I would not expect them to look like that.

It looks like it might be front side IR leak perhaps? If scope cover is plastic, and plastic can sometimes be transparent to IR wavelengths. This would also mean that you did not have UV/IR cut filter in place when you took your darks.

In any case - making sure you don't have a light leak would be first priority. I can't explain that brighter patch, but let's see if you have a light leak issue and if solving it solves other issues.

[Anthonyexmouth]

17 minutes ago, vlaiv said:

I think you have a light leak.

You should not have such gradient on your dark, and there are hints of dust shadows, although, depending on type of light leak - I would not expect them to look like that.

It looks like it might be front side IR leak perhaps? If scope cover is plastic, and plastic can sometimes be transparent to IR wavelengths. This would also mean that you did not have UV/IR cut filter in place when you took your darks.

In any case - making sure you don't have a light leak would be first priority. I can't explain that brighter patch, but let's see if you have a light leak issue and if solving it solves other issues.

the l pro filter should have IR cut. hopefully it's light leak. i cut a perfect circle of 70mm celotex to fill the dew shield and then the cap went on top. I'll shoot some more later when its dark and hopefully won't eat into my imaginig time too much. 

thanks for your reply .