Martin Aislabie
Subscriber
That's my point Trevor, if the system is set up correctly centre focus should be all that's needed.
Dave/Trevor, my line of thinking is:-
If there is no grain to focus on as we are using 5x4 then focus on other details on the neg.
The other details might not be in the centre of the picture - hence can you still see the corners of the photograph through the Peak device - as that might be where the details to focus are.
I am not trying to check for lens/baseboard alignment or evenness of centre/edge lens focus just trying to maximise the focusing options.
After all investing 100+ UK Pounds on a focus finder that doesn't cut-it or really offers no greater coverage performance would defiantly spoil my day

Martin