Fingerprint in CCD center after turning on cameras

[noralinn]

I took some test images with M1 and noticed the "fingerprint issue" in the first two images taken with M1C3. In the third on it's gone.

I think we were suspecting static electricity or condensation, but never figured it out.

With fingerprint:
LAST.01.01.03_20240211.133853.241_clear_020+00_001_001_001_sci_raw_Image_1.fits
LAST.01.01.03_20240211.133920.322_clear_020+00_001_001_001_sci_raw_Image_1.fits

Fingerprint is gone
LAST.01.01.03_20240211.134153.583_clear_020+00_001_001_001_sci_raw_Image_1.fits