[vanwonky (Dave)]

I will go the reducer / flattener path when I have taken more images and know what I need exactly I think.

Since the diagonal allowed me to come to focus is it just simple maths to work out what length extension I need i.e - the 2" diagonal gives me 110mm + what I had the drawtube extended out to which I need to check again but was about 20mm. So the drawtube will do 80 on its own (max) + a 50mm extension will get there maybe.

I guess I wouldn't want to leave it too exact and have some play so a bit more wouldn't hurt but am I right in thinking to much could cause vignetting?
Cheers
Dave

EDIT: the drawtube was only out 7mm when I used the diagonal so 117mm-ish needed to reach focus.