Help Toyo View D45M Focus problems

[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.



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.







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.