I do have the light shroud. Like you I do my observing from the back yard and it does keep out stray light. It was highly overpriced but there is a cheaper version on the go now. Making your own will work just as well.

http://www.astrozap.com/pages/shrouds.html

Ive never used the cooling fan. My normal set up routine is after I coliminate I go make myself a cup of tea and have a ciggy by which time the mirror is cooled. But TBH I havent noticed any difference when observing right away.

APOD: Yeah dial to zero is off

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