Help Toyo View D45M Focus problems

[photojpg]

Hello all,
I am new to LF photograhy but have been taking and printing my own photos for quite a few years. I recently purchased a Toyo D45M. The problem I am having is that the focus is shifted, I focus on an object and on the GG it looks great, but when I look at my negatives what I focused on is soft and things a few feet back from it are very sharp. I have checked the fresnel lens and GG and it looks like it is installed correctly from info I found online from Toyo. This model camera seems to have come with the fresnel lens installed from the factory, all the D45m's I see have one. What could be the problem, I am at a loss? Any help is appreciated.

[Tin Can]

Consider 5 things.
Format
Lens FL
Where to focus
DOF desired
Aperture desired

This free tool is useful

http://www.dofmaster.com/dofjs.html

After that you have movements.

[photojpg]

I know where I am focusing and about DOF etc. the focus is never on the object I focus on for example a still life of a camera on a shelf, the camera turns out soft and and behind it is sharp. Thank you for the link that tool looks very useful, I will try some of the suggestions there.

[Tin Can]

https://digital-photography-school.c...going-outside/

Maybe the lens, test it all

[Maris Rusis]

If the focus you get on the film is clear for objects further away that the ones you focussed on in camera then the film is closer to the lens than the ground surface of your ground-glass. Two initial possibilities:

The ground-glass might require a fresnel between it and the camera lens. The effect of a fresnel is to shorten the optical distance between the ground-glass and camera lens. If the camera was designed to incorporate such a fresnel and it is missing then the ground-glass is too far from the camera lens and you will get the back-focussing problem you see.

The ground-glass may be in backwards with the ground surface facing away from the camera lens. The size of the focus position error is the thickness of the ground glass and again back-focussing is the unfortunate result.

[photojpg]

Actually the camera has a official Toyo fresnel lens and a ground glass, it came this way from Toyo and everything is installed correctly. the fresnel lens is in front of the GG and everything is facing the proper way. it's a mystery.

[ic-racer]

Since the subject in focus is behind where the ground glass shows, the film is closer to the lens than expected. Rather than moving the film back, try moving the ground glass forward. For example, see what happens when the fresnel lens is removed and the ground glass is moved forward.

[Rod Klukas]

As people have suggested the addition of glass or fresnel, and even filters will move the focus 1/3 the thickness of the added glass.

My suspicion is the fresnel is reversed. The smooth side of the fresnel should be on the lens side and also the ground side of the glass is also correctly placed when the rough or ground side faces the glass.

In terms of a focus aid, if you use one, it should not be higher than 5x in magnification. If higher it begins to magnify the pattern of the GG or even the rings of the fresnel. *x and higher are definitely not good. The Hoodman loops for LCD screens are good at 2-3x.

Finally check the rear group of the lens is crewed all the way into the lens. We focus wide open as is correct. But when we stop down the lens the Red wave lengths move forward and cause softening of the image. This may be somewhat covered by stopping the lens down as can be done with film photography. For normal lenses 135mm and longer you should always stop down at least 2 stops for best quality. For wide angles as this red movement is worse, 3 stops are called for.

Hopefully this may be of help for you.

[photojpg]

Now that I'm home I see how it fits together, the fresnel lens is held in by clips and it is smaller than 4x5, so even though the GG is sandwitched with it the fresnel lens does not effect the spacing of the GG, the GG is flush like it should be with or without the fresnel, the GG still sits in the same place. So I will try some focus tests tonight.

[photojpg]

I'm positive nothing is reversed or put in backwards, it is all facing the correct direction. Yes the fresnel has the shiny side facing the lens like Toyo states.