I've not used my camera for a few months. Using it again this week I have a grid pattern on the light frames. I did a four hour imaging session Soul Neb_300sec_1x1__frame12.jpgSoul Neb_300sec_1x1__frame25.jpgSoul Neb_300sec_1x1__frame28.jpgwith the camera cooled to -15C. The pattern was there for 3 hours and then gradually shrank until the frames were clear by about 31/4 hours.
Is this coming from the anti-dew heater which I had checked in the properties? I've never seen it before.
What can I do about it?
Thanks
Chris Marshall