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dazedgonebye
28-Apr-2009, 16:57
Hi,
Starting a new thread because I need help.

I'm trying to get the 75mm lens mounted to the Gran View I bought. The problem is that it will not focus more than about 8 inches away from the front of the camera.
I removed the lens from the mount and I find that I can get infinity with the lens well back in the mount. The shutter is about half way in to the throat of the lens cone.
No amount of mounting error could cause this...we're talking a good half inch off.

I tried mounting a 90mm lens, thinking that perhaps the cone was not made for 75mm after all, and it is not long enough to focus the 90mm lens. I have to hold it and the mount well away from the cone before I can focus.

So, I'm not sure what to think.

Any ideas?

dazedgonebye
28-Apr-2009, 16:59
One additional bit of information.

The flange distance measures about 70mm at its minimum and 78mm at its maximum.

Why the heck would the lens need to be closer than 70mm?

Gem Singer
28-Apr-2009, 17:15
Perhaps it was made for a 65mm lens?

dazedgonebye
28-Apr-2009, 17:29
Perhaps it was made for a 65mm lens?
If that were so, wouldnt te 75mm lens need to be further away from the film plane instead of closer?

EdWorkman
28-Apr-2009, 17:29
From the previous thread:
two helices
#1 sets the lens at the proper distance for its focal length and is locked off.
#2 varies the focus of the lens.
Does that fit into this query?
Can you shift the base point of the lens, as for "helix #1", or is the plate you made in place of the first helix? Can you show us a pic of the lens with mount?

dazedgonebye
28-Apr-2009, 17:44
The helical is as you describe, but the lens wont focus no matter how close in it is adjusted....by 10mm or more.

Gene McCluney
28-Apr-2009, 17:51
The problem is that every different "brand" of 75mm lens will have a different point at which it focuses. If you did not mount the particular brand (Schneider, Rodenstock, Nikkor, Fuji, etc) of 75mm then you may be out of luck. Do you know what "brand" the camera helix was designed for? I was afraid you might run into this problem with an inexpensive "off brand" of plastic helicoid focusing camera.

On a bellows equipped view camera it doesn't matter as the bellows has almost infinite adjustment.

dazedgonebye
28-Apr-2009, 17:55
No idea of the intended lens except to say that it is copal 1 and its intended for a flange distance of between 70 and 78mm flange distance.

Gene McCluney
28-Apr-2009, 18:00
The "theoretical" flange distance for a 75mm lens at infinity should be 75mm, but in practice different lens designs place the infinity distance sometimes differently. If you can get a sharp image across the whole frame at SOME point of distance between the camera and the lens, then the lens is OK, just not suited for your special application.

jb7
28-Apr-2009, 18:05
My 65mm /8 Super Angulon has a flange to focal plane distance of 70.5mm at infinity-
looks like the cone might be for a 65mm...

dazedgonebye
28-Apr-2009, 18:05
the schnider site says something like 82mm flange distance. why would this lens need to be closer than 70mm?
Im missing something.

Gene McCluney
28-Apr-2009, 18:18
The "wayback machine" storage of the Grandview website is quite interesting.

http://web.archive.org/web/200404141.../sbreview.html

Seems the camera could be had with 65mm, 75mm and 90mm cones. Just because the seller on ebay "said" it came with a 75mm cone, are you FOR SURE that is what you got? Does the cone actually have some engraved stamping on it or something to give you a positive identification that it is for 75mm lens? One thing I am getting from reading the old website, and Roger Hicks review of the camera, was that it was designed really for the less expensive lenses (if that makes a difference) such as the f8 lenses, not the f5.6 lenses. Don't know if it makes any difference. Unless the flange distance is different between the f8 and f5.6 lenses.

Gene McCluney
28-Apr-2009, 18:20
the schnider site says something like 82mm flange distance. why would this lens need to be closer than 70mm?
Im missing something.

Ah, but your cone may not actually deliver you 70mm. Did you actually measure the distance from the hole where the shutter mounts to the ground glass?

Gene McCluney
28-Apr-2009, 18:22
You may actually have the 90mm cone, which would put your lens too far out, just as you describe.

dazedgonebye
28-Apr-2009, 18:23
Ah, but your cone may not actually deliver you 70mm. Did you actually measure the distance from the hole where the shutter mounts to the ground glass?

yes I did. Thats where I got the 70mm number.

Gene McCluney
28-Apr-2009, 18:33
Well, I don't think there is any thing you can do to get your existing fine lens to work.

Gene McCluney
28-Apr-2009, 18:34
I will say that I've got a 90mm Angulon, and a 90mm Super-Angulon, and they both focus infinity at different distances from the ground glass.

dazedgonebye
28-Apr-2009, 19:10
Ok, from the top.

With the helical set to infinity, I get a flange distance of 70-78mm.
The lens will not focus until I get it closer than 70mm.

Shouldn't I conclude that something is wrong with the lens? Surely a 75mm lens, would have a flange distance of more than 70mm? This one seems to need something closer to 65mm.

Gene McCluney
28-Apr-2009, 19:13
Ok, from the top.

With the helical set to infinity, I get a flange distance of 70-78mm.
The lens will not focus until I get it closer than 70mm.

Shouldn't I conclude that something is wrong with the lens? Surely a 75mm lens, would have a flange distance of more than 70mm? This one seems to need something closer to 65mm.

Impossible to say unless one has another identical lens to test. Maybe someone who has the Schnieder Super-Angulon 75mm f5.6 can measure the flange distance on theirs and report back. You did say you could get it to focus, just not at 70mm distance, so I'm thinking the lens is OK.

dazedgonebye
28-Apr-2009, 20:43
Additional information.

I contacted the seller to see if he had any history with this lens. He's telling me that it's possible that he mixed the rear element with one of two other lenses when the shutter was getting a CLA.
He's sending the other elements so I can try to match things up.

I'm thinking that could explain things. Let's hope.

dazedgonebye
1-May-2009, 14:31
Wooo Whoooo!

I received the correct rear element today and it's looking good. I can get infinity and am working on setting up the focus now.