[Aavso-photometry] Screen for "dome" flat?

[Tim Crawford]

Jim,

I purchase white "boards" at a local artist shop; they usually have them constructed of several different materials and sizes (think big).

Then I bounce a 40 watt GE "Reveal" light bulb off of the white board(s) while the scope is  pointed at the "boards."  Your distance is going to be a matter of experimentation.   I have the bulb installed in a reflector and added a rheostat switch to the line so I can control the brightness of the bulb
as differing levels are required depending upon the filter.

Simple and seems to be reasonably effective.

I will confess that for awhile I "foolishly" (IMO) used an opaque screen over the corrector plate until a friend asked me why in the world I would introduce something in to the optical path that is not there when I am imaging.... Never used it again.

ad Astra

Tim Crawford CTX
Arch Cape Observatory

http://homepage.mac.com/windwalker1/ACObserv.htm