Spot on new camera sensor/glass cover

[pkinchington]

I just purchased a new cooled mono camera the QHY163M. I did a test run to see if there were any issues. To my disappointment I see that there is a blemish spot that I have circled - Is this on the cover of the sensor or the sensor itself I cannot see anything when I look at the sensor/glass. Is this a concern and should I return the camera? I have attached three downsampled images which show that the spot must be located on the sensor or sensor glass because the spot has not shifted within the frame.


Regards Kanga

[sunslayr]

Looks like it's on the front AR window as its slightly out of focus. You could probably blow it off with one of those little camera dusters. This (https://www.qhyccd.com/bbs/index.php?topic=6280.0) is a post from qhy on cleaning, I don't think it violates the warranty. Try blowing the outside first though.

Edit: I should also mention you don't need to do this as it will calibrate out with flats.

[pkinchington]

Thanks if it will calibrate out I might leave it. I did try to dislodge it if it was external dust by using a blower brush but to no avail.
Cheers Kanga

[glend]

Clean optics are essential to imaging without Flats. If you can, clean it. I have cleaned AR windows before on ZWO cameras and it is very easy (On those). Post some photos of the camera and we can work it out.