in the past i have taken flats with my light box which gave me great, evenly illuminated flat images. since setting up the observatory i thought i would take flats before an imaging session during dusk but i have found there is about a 15 min window where i am not shooting many stars and my sensor is not being saturated which makes it difficult to get the flats i need. granted i am shooting at f4 (10") with a 8300 sensor so i might get a bit more range when i am shooting at higher f and a different sensor. regardless, i am thinking that it would be better to get flats that are taken off a consistent and even field.
i just wanted to get a feel for what others use ...
there is this option
http://www.optecinc.com/astronomy/ca.../flatmanxl.htm
a little expensive so i was thinking of making one.
maybe converting one of these
http://www.ebay.com.au/itm/ECO-Light...-/191606944777