Please take a look at these two FITs files. One taken right after the other. Notice the black dots on the lower half of the screen. If history is a guide these dots will be all gone within an hour or so. What are they? I thought ice, but that would be strange. It diminishes over time? Perhaps because of heat in the camera? Also, there's a new desiccant plug in the camera so there should be no moisture, ergo no ice. So, this must be something else. Thanks for your help. https://www.dropbox.com/sh/95p81eu9hdoimqs/AADIfs2IR-it_F_Nl0OGGIqya?dl=0
Yes, that would be frost. It will tend to diminish over time because the top of the thermoelectric cooler stack is slightly colder than the front of the CCD sensor. The moisture slowly migrates to the coldest place. Time to recharge your desiccant.
Since we don't have an oven on site we took the plug from a new camera...evidently that plug needs to be recharged too. We'll take them both offsite to complete...
Thanks for the insight. We'll use that after baking the "new" plug. The current plug, from a new camera, has been in for 2 weeks.