it's condensation - which is when the chip cools quickly and the air is warmer around it, which causes moisture to form on the chip.
some things to do:
keep your camera outside so it's about ambient temperature
cool it slowly over time - like 20-30 minutes, and it will lessen the difference in temperature over time and minimize condensation
wait until condensation clears.
have realistic expectations - the 071mc is a huge chip by astro standards, so realistically i see -25 to -30c difference to ambient, and that's tops.
i think most folks who have this problem don't realize it takes time for condensation to clear
good luck
Brian
