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.com/an-exercise-for-you-to-practice-depth-of-field-without-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.

[photojpg]

I will photograph something flat and see how that looks.

[photojpg]

187485187486187487187488

Here are some photos of the setup.

[Ernest MacMillan]

This question is complicated by the fact that Toyo produced two almost identical ground glass frames with different registration distances for the ground glass. If that is not enough, the Fresnel lens may be clipped onto the ground glass in both frames, but will need spacers that were once available in a kit for the sandwich to focus correctly in one of the frame designs, but needed no such spacer in the other design. I found this out the hard way. And dealers/owners switch them. I am sure you have enough to worry about, but I thought I would share my experience anyways. The ground glass frame of the 45C did not come equipped with a Fresnel, the special kit of Fresnel plus spacers was 180-803.

[photojpg]

I know it's been a little frustrating, all the D45M models I see online have the same exact setup as mine. I took a photo with just the ground glass and will develop it tomorrow and see if that makes a difference. It actually is easier to focus without the fresnel installed and not noticably any dimmer.

[ic-racer]

all the D45M models I see online have the same exact setup as mine.


You are way ahead of the game since you have detected the problem in the first post. Don't group yourself with the less astute.
Even in the old days when one could sent a LF camera for repair, it would unlikely come back so it focuses the way you want with your film and film holders. No one except you know how you position the image plane when you focus, or how your film holders hold the film.

Obviously, unless the film holder is damaged or improperly made, the T-distance can never be greater, but it can easily be less if the film is bulging or is not pressed against the back of the holder. This condition of improper film placement, of course, places the focal point farther back in the scene, than expected.

[Doremus Scudder]

photojpg,

You have correctly diagnosed your problem: a misalignment of ground glass/Fresnel screen. Don't get hung up on your preconceived notion that everything is exactly as it should be; it's not.

As others have said, if the focus on the film is more distant than the focus on the ground glass, then the film is closer to the lens than the ground glass (or, maybe more helpful, the ground glass is farther back from the lens than the film). This would mean that you would have to find a way to set the ground glass further into the camera back, not an easy task on a metal camera unless you're a machinist. If that is the case, then likely the Fresnel screen is simply not supposed to be where it is. Your experiment with ground glass alone should tell the tale.

If the focus on the film is closer than that on the ground glass, you have the opposite problem: the ground glass is too close to the film. This is much easier to deal with by simply making shims and installing them till you get the right spacing (you can often estimate closely how much shimming you need by returning to the test subject with your notes and the test negative in hand and then focusing on both places and noting the difference).

A good test is to photograph a ruler at an oblique angle to the camera, focusing on a middle value (e.g., the six-inch mark) and then shooting wide open. Develop the neg and see where the focus really is and adjust accordingly. To control, shoot a wide-open shot of a distant jagged horizon line, and see if it is in sharp focus.

FWIW, I do this with my cameras fairly regularly when I'm printing. I'll take the camera outside, photograph the horizon, walk into the darkroom and develop the neg in the print developer for three minutes or so. Stop, fix for a few seconds and inspect the wet neg with a loupe. If all is well, the neg goes into the trash and I resume printing.

Best,

Doremus

[photojpg]

Thank you to everyone for your suggestions and help. I removed the fresnel lens which does not effect the distance of the GG and exposed some photos last night. I photographed some flat objects close and others I out behind it at different intervals. I just developed those negs (my first try at tray developing with pmk) and so far they are very very sharp where I focused and the distant objects are blurry like they should be. I can only assume that the fresnel lens was causing it to focus incorrectly, the image is easier to focus without it. There must have been something wrong with the fresnel. I have ordered a fresnel GG combo screen and will see if that works as well, hopefully it is brighter and focuses correctly. If not I will just use my GG I have now. I still have to take some regular outdoor photos and see how they come out. It is raining here now so hopefully tomorrow, thanks again!

[Doremus Scudder]

A Fresnel screen between ground glass and lens will refract, i.e., change the apparent focusing distance, one third of its thickness. If you're getting good focus without the Fresnel in place, then it likely shouldn't have gone in that position, or the whole sandwich needed to be displaced by the proper amount. Would shims help?

Doremus

[Audii-Dudii]

Thank you to everyone for your suggestions and help. I removed the fresnel lens which does not effect the distance of the GG and exposed some photos last night. I photographed some flat objects close and others I out behind it at different intervals. I just developed those negs (my first try at tray developing with pmk) and so far they are very very sharp where I focused and the distant objects are blurry like they should be. I can only assume that the fresnel lens was causing it to focus incorrectly, the image is easier to focus without it. There must have been something wrong with the fresnel. I have ordered a fresnel GG combo screen and will see if that works as well, hopefully it is brighter and focuses correctly. If not I will just use my GG I have now. I still have to take some regular outdoor photos and see how they come out. It is raining here now so hopefully tomorrow, thanks again!
Although I don't remember the details, I do recall that Toyo used a non-standard setup regarding the orientation of its fresnel lenses and ground-glass.

As such, I suspect your fresnel lens is fine in and of itself, but simply wasn't installed correctly.

[photojpg]

I got instructions from Toyo on the correct order and which way the shiny side faces, it faces the lens which is not Ike other fresnels, its a mystery as to why it works better now. I'm positive it was installed correctly since I followed the directions from Toyo and that is the same may it can when I bought it. I cleaned it the proper way and installed it the way Toyo says in the directions. My camera is very old it was made in 69 or 70, it's the tan one.

[Tin Can]

All I know is there were some years where Fresnel position moved around.

I have two 8X10 Horseman backs that look identical and pure OE.

One has the Fresnel on the lens side and the tuther the eyeball side.

And both seem to work OK for this blind old man.

I do some odd things now to focus anything...

[Ernest MacMillan]

As mentioned before, I have two different frames, of a more modern vintage than the poster. One was obtained with a Toyo 45A2, from a reputable dealer, but without Fresnel. A second was purchased with Fresnel as part of a whole rotating back from another dealer.

187550

The frames appear to the eye to be nearly identical, and the ground glass sandwich is shown above them (glass on bottom, Fresnel on top wrt this picture); the ground glass rides on the milled ridge in either frame whether or not the Fresnel is attached, as the latter is somewhat narrower in width. The Fresnel ridged side faces the etched side of the ground glass, with the smooth side of the glass facing the viewer and the smooth side of the Fresnel facing the lens -exactly as in the poster's setup. When I measured the depths of the ground glass alone in the frames with my homemade depth gauge ($60), I obtained the result that one registered at 0.187 inch deep and the other at 0.208 inch - the first is within ANSI tolerance of 0.190 inch (assuming 0.007 inch film), the other is clearly off 0.018 inch and out of tolerance. The measurement process is illustrated in the next three pictures for one frame. Note that there are four raised bosses on the frame that one must reference from.

187559

187560

187561

I put the ground glass in the frame that was more or less correct and the groundglass/ Fresnel in the slightly deeper frame. I put a 180mm lens, wide open at 5.6, in the camera and focused on a slanted ruler about 5 feet away, locked focus and other controls and switched between the frames examining the same spot on the ruler with a 10x loupe. For whatever it is worth, I could tell no difference in sharp focus between them. So, for me, the Fresnel, mounted with an implied spacer of 0.018 inch, is indistinguishable by me under these conditions from a correctly positioned ground glass. It is even possible that either frame works equally well, but I am satisfied that it is close enough the way I arranged it. Better eyes, or tighter standards, might dictate a less optimistic conclusion. I should add in passing that the Toyo etched screen is a joy to focus on, surpassing my Maxwell screen in ascertaining sharp focus, albeit if not illuminated as well.

[photojpg]

Yeah your frame that sandwiches them together looks different than mine but everything else you stated about how the GG sits on the ridge with or without the fresnel is the same. Tomorrow night I will take a photo with the Fresnel GG 2 in one I ordered. I think it should be brighter but I also hope it is as easy to focus as the GG I have now. I do a lot of photos in old barns with dim lighting so it is pretty hard to see anything on a dim GG I use a bright flashlight to focus but that does not really do much for the edge brightness.

[MikeH]

Maybe you've solved your problem, but ...I took my D45M apart and compared it to your pix. In pix #1, the fresnel is on the top, and in pix #3, it's on the bottom? The only thing I could see: the "4 inch" side of the fresnel should fit flush to the frame, although I don't think you could tighten the 6 screws if it didn't. Otherwise, everything looks fine.