Hello
I am a student Photography at a Belgian art academy (7th year) and quite new to this community. For my last 3 years of specialisation I am busy making my own 4x5 field camera in Mahogany wood to make portraits. So far everything fits well. I must admid I spent since August more hours than first expected to build this camera (total now 80 hours). The camera is almost ready. I am now building a wooden frame that will fit on the back of the camera with the Fresnel and ground glass. I also have a plastic Ilford 4x5 film holder. I know there are some standard distances from the top of the holder to the mid (film) support and now comes my question : I need to respect the same distance so that the focuspoint on my groundglass matches perfectly (tenth's of a mm tolerance ?) with the plastic holder which will put once the focus is correct between back and groundglass holder. As my Fresnel + groundglas are +/- 2.7 mm thick I would like to know the exact focus point I need to respect :
is it :
- entrance at the Fresnellens at same side as the lens in front
- the transistion between Fresnel and groundglass
- the groundglass at my eye side ?
If the question is not clear - please ask me I will make if necessary a drawing to explain.
Every help is welcome.
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