Correct use of EL Panel for Flats

[Moon]

What is the best way to use EL Panels for flats? Is it ok to mount it in a frame and hang it on the wall of the Observatory?

Or does it need to be mounted in a box and put over the end of the telescope? :question:

[h0ughy]

provided you have the diffuser on it you just put it over the end of the scope - or aim the telescope into the box?