Without a heater on a SCT you ll get 0 chance of success if Dew rears its head , there would have to be some impact I guess but depending on your dew control system you can lessen the chances with a adjustable controller like the kendricks or dew-buster . Interesting i was out two times in the last week imaging Mars and the first night i had the scope out in the afternoon to cooldown and the conditions where good in the evening with no dew but I got better results the next night when i got home late from work and virtually set the scope straight away from the garage and had to use my heater
