Trouble Focusing

[spacegoose]

I recently had a session with my 8x10 Deardorff and couldn't find my loupe - so I used a larger one I normally use for examining negatives.

The back I use has a Fresnel. I haven't used the camera much but I found focusing (wide open) to be more difficult than I remember. I am also using a lens not as fast as I've used in the past.

I'm not sure if my difficulty is because I wasn't using my normal smaller loupe, or because of the different slower lens, or what; or does one have an easier time focusing on a ground glass vs Fresnel?

The difficulty I experienced was, under the loupe, I had difficulty seeing the point I wanted to focus on, it would just turn black sometimes. I believe I had to be at _just_ the right angle or the image would disappear.


Thanks for any info!

sg

[Mike1234]

Upgrade to a Maxwell screen and use +6 reading glasses instead of a loupe.

[Steve Hamley]

If the loupe is designed to view negatives, the focal plane is at the front edge of the loupe. Your image-forming surface on the GG is probably 1/8 or more in front of that, and if the fresnel is frosted with a cover glass, more like 1/4".

Cheers, Steve

[spacegoose]

Reading glasses sound like a great idea I hadn't thought of. Thanks! I'll try with my existing Beattie to start. Spoke with a very helpful/knowledgeable Bill Maxwell just a moment ago about a screen (he recommended the Ultra Brilliant for my mostly indoor formal portraiture) - I'll have to postpone until more funds become available Bill mentioned something about the perpendicularity of the light or glass and the base of my loupe as a possible explanation for my recent focusing trouble, though I didn't mention the other factors (loupe, lens).

[spacegoose]

Thanks for the info Steve - I sort of understand: the loupe I used was the culprit - any way to make the explanation more understandable to me, seems to have messed up the focal planes (or just make sure to look to the front of the larger loupe)? In any event despite the difficulty I had, I was able to see images become in focus (though it was quite a pain) - I haven't processed my film - do you expect it was _really_ in focus, or not?