Flat Fields

[Eternal]

My understanding is that flat fields are needed in order to reduce vignetting and need to be taken under the same conditions that the actual photograph are taken under. If this is correct, what is the best way to do this? I've read somewhere that one method is to simply stretch a white t-shirt over the front of the telescope, are there any better methods out there?

TIA

[[1ponders]]

G'day Eternal. The best explanation I can give is this one by Eddie Timarchi. (http://www.iceinspace.com.au/index.php?id=63,211,0,0,1,0) ;)

[rogerg]

I'd suggest sarching the forums. I very recently participated in a thread with almost exactly the same question, think it was in the beginners forum.

Roger.