Zone VI 4x5 Camera - Ground Glass Alignment

I've been using the Zone VI 4x5 since I purchased it (new) in 1997. I'm not

sure what "vintage" it is. I've been quite happy with it, and have learned to

work around its weaknesses, which have been discussed elsewhere on this

forum. As Mae West used to say, "It's a poor craftsman who blames his tool."

 

Anyway, I've just learned of a very interesting design issue that I did not

see mentioned on this forum. One of the most difficult things for me is to

compose a photograph without horizontal convergence. This past week I was

photographing inside of a large rectangular room. I had myself positioned

exactly half way along the longer wall (I measured carefully). I had all of

the controls square and centered, and the back perpendicular to the ground.

Using a 58mm lens and the bag bellows, I was photographing the opposite wall.

I panned the camera until the opposite wall was centered in the ground glass,

and discovered that the floor and ceiling lines converged quite noticably. I

checked that the lens was not off-center, and I checked that I was in the

center of the wall. And yes, the room was square. Since I had such a short

lens and the bag bellows, I was unable to slide the lens sideways enough to

correct the problem, so I panned the camera until the convergence disappeared,

and made the exposure. I'll plan on cropping the image to be symetrical.

 

Back in my studio this morning, I got out my dial caliper that reads to 0.01

inch, and began to check the dimensions of the camera. To my great surprise,

I discovered that my ground glass is off-center by 0.14 inch when the back is

in the horizontal position. Looking from the back of the camera with the film

holder oprning facing right, it is off center to the right. If I rotate the

back 180 degrees, it's off center to the left. From previous testing I know

that the visible area of the ground glass closely agrees with the image on the

film, and that the focal plane of the ground glass is also the same as the

film.

 

Has anyone else seen this with the Zone VI camera (or any other LF camera)?

Now I know it's there I can compensate for it, which I'm sure would make Mae

West happy.

Wooden field cameras are typically not made to the same precision as most metal view cameras. Your camera has the important aspects correct: the ground glass shows what you will get on the film, and the ground glass is correctly positioned to get accurate focus.

 

I used a Zone VI Classic for many years. One reason that I switched to a different camera was that it was akward to use with wide angle lenses. I bought mine fairly soon after it was designed and first released -- that was before Schneider designed the 58 mm Super-Angulon-XL. In that era 75 mm seemed really wide for 4x5 -- probably the widest lens in many amateur's kit was 90 mm.

 

The various field cameras sold under the Zone VI name are discussed at http://www.photo.net/bboard/q-and-a-fetch-msg?msg_id=00Cilx

This seems to be more than just a manufacturing tolerance issue. 0.14 inch is more than 1/8 inch. All other aspects of the camera are carefully machined, so I'm really puzzled about this mis-alignment.

Paul -

 

I suggest asking Richard Ritter. Richard worked with Fred Picker to design the Zone VI and may know if the anomaly you have found was intentional or inadvertant.

I have one of Fred Picker's "made in Vermont" Zone VI 4x5 cameras which I have used and

loved since I bought it back in the 1980s. Yes, the tolerances are kind of "loosey-goosey"

so I have limited my subjects to those things which are not greatly affected by the

imprecise tolerances. When I need really close tolerances in a field camera, I rely instead

on a monorail field camera made by Cambo which isn't too heavy.

58mm on a Zone VI! You must like doing this the hard way. That has to be incredibly cramped.

 

I just tried it. Do you find it easier to use the regular bellows at that length? I didn't get as much swing, but about the same amount of tilt. The screws are easier to get at, and the bag doesn't squish out the sides of the rear frame.

Thanks, Louie -- I have just sent an e-mail to Richard.

 

As for Aaron's comment, yes, the camera is quite "tight" with the 58mm lens. I've done some good work with it in the past, but it requires the bag bellows, and also requires that the bed be tilted forward, the back then leveled, and the lens raised pretty much all the way (to center it again) to avoid getting the front of the camera in the photograph. Here's a link to one of my photographs with the 58mm lens:

 

http://www.paulwainwrightphotography.com/p02_07.shtml

Well, I'm glad I chanced upon this thread. I had basically written off any lens 75mm and shorter.