medium format wide angle shift lens

[jlamarca]

There don't seem to be many solutions for shift in medium format. What I want is a wide angle lens (45-55mm) that can do vertical shift and be fitted on the Pentax 67. Pentax sells a 75mm shift lens but that is just a bit too long. I'm doing architectual/urban landscape work

Please correct me if I'm mistaken in my thinking about the way lenses and large format cameras work (since I've never used one). I'm thinking out loud here...

The obvious answer is "get a view camera with a 6x7 back." I would be fine with that, except for the viewfinder. As I understand, with a 6x7 back on a view camera, you can't use the ground glass. You have to use an external viewfinder. I would much rather use the huge, bright viewfinder (waist level or eye level) of a medium format SLR, and TTL metering is nice too. Plus external finders do not show your shift nor focus (a pocket rangefinder is necessary, for the shift you just have to guess).  So, with an SLR, you get to frame the shift, focus and meter all at once. That's a huge advantage for me over a 4x5 camera with 6x7 back.

But while wide shift lenses exist that cover 6x6 or 646 (Hartblei, Zoerk adapters), nothing wide seems to shift and cover 6x7. And I really want to use the 6x7 perspective, and the whole piece of film (no cropping). Yes, there is the Fuji gx680, but it is the size of a car.

The problem, I suppose, is image circle size. So that would mean the solution is use a lens with a big image circle - large format lenses (the super angulon 47mm has 166mm diameter I think). But that creates another problem: how to mount this on an SLR like Pentax 67 in a way that allows focus at infinity.

Perhaps this is impossible, and wide angle large format lenses need to be very close to the film plane to focus, leaving no room for a mirror. But if 45mm shift lenses can mount on a 6x6 SLR, why not on a 6x7? All that's needed is a little bigger image circle, no?

Has anyone dealt with this problem themselves? Or does anyone know a place that does custom lens modifications?

Thanks!

[Anders_HK]

There don't seem to be many solutions for shift in medium format. What I want is a wide angle lens (45-55mm) that can do vertical shift and be fitted on the Pentax 67. Pentax sells a 75mm shift lens but that is just a bit too long. I'm doing architectual/urban landscape work

Please correct me if I'm mistaken in my thinking about the way lenses and large format cameras work (since I've never used one). I'm thinking out loud here...

The obvious answer is "get a view camera with a 6x7 back." I would be fine with that, except for the viewfinder. As I understand, with a 6x7 back on a view camera, you can't use the ground glass. You have to use an external viewfinder. I would much rather use the huge, bright viewfinder (waist level or eye level) of a medium format SLR, and TTL metering is nice too. Plus external finders do not show your shift nor focus (a pocket rangefinder is necessary, for the shift you just have to guess).  So, with an SLR, you get to frame the shift, focus and meter all at once. That's a huge advantage for me over a 4x5 camera with 6x7 back.

But while wide shift lenses exist that cover 6x6 or 646 (Hartblei, Zoerk adapters), nothing wide seems to shift and cover 6x7. And I really want to use the 6x7 perspective, and the whole piece of film (no cropping). Yes, there is the Fuji gx680, but it is the size of a car.

The problem, I suppose, is image circle size. So that would mean the solution is use a lens with a big image circle - large format lenses (the super angulon 47mm has 166mm diameter I think). But that creates another problem: how to mount this on an SLR like Pentax 67 in a way that allows focus at infinity.

Perhaps this is impossible, and wide angle large format lenses need to be very close to the film plane to focus, leaving no room for a mirror. But if 45mm shift lenses can mount on a 6x6 SLR, why not on a 6x7? All that's needed is a little bigger image circle, no?

Has anyone dealt with this problem themselves? Or does anyone know a place that does custom lens modifications?

Thanks!
[a href=\"index.php?act=findpost&pid=208827\"][{POST_SNAPBACK}][/a]

Hi,

My thoughts on shift & panoramic stitching for my digital back has made me interested in Ebony SW45, see www.ebonycamera.com. It has also made me think of trying large format film... all in thoughts at moment!

Per what I read SW45 is designed for wide angle lenses and works also with 35mm lens with recessed lens board.

Regards
Anders

[BernardLanguillier]

The obvious answer is "get a view camera with a 6x7 back." I would be fine with that, except for the viewfinder. As I understand, with a 6x7 back on a view camera, you can't use the ground glass. You have to use an external viewfinder. I would much rather use the huge, bright viewfinder (waist level or eye level) of a medium format SLR, and TTL metering is nice too. Plus external finders do not show your shift nor focus (a pocket rangefinder is necessary, for the shift you just have to guess).  [a href=\"index.php?act=findpost&pid=208827\"][{POST_SNAPBACK}][/a]

On regular view camera, you attach and detach the film back in a matter of less than 30 seconds.

You tipically frame and focus using the ground glass, and replace the GG by the film holder when you are done.

I used to do that often on my Ebony 45SU and the process is really straightforward. I don't think that 30 sec really make a big difference for architecture shots. It takes much longer to frame correctly and check for critical verticality, etc... not to mention lighting that would take 2 order of magnitude longer to set up.

Cheers,
Bernard

[jlamarca]

Ah, OK, I didn't realize you could attach and detach the roll film holder in the middle of a roll. As I said I know very little about LF. I guess there is some kind of cover that slides over the film to protect it from the light when you detach it.

Anyway, would still be curious to hear anyone's take on the modification thing for 6x7 SLR...

[BernardLanguillier]

Ah, OK, I didn't realize you could attach and detach the roll film holder in the middle of a roll. As I said I know very little about LF. I guess there is some kind of cover that slides over the film to protect it from the light when you detach it.
[a href=\"index.php?act=findpost&pid=208837\"][{POST_SNAPBACK}][/a]

Yes, there is indeed a metallic slide that protects the film when the back is not on the camera.

That is at least the way my 2 Horseman backs are designed (6x9 and 6x12).

Cheers,
Bernard

[jlamarca]

After much searching, I'd have to say that GBPhoto is correct. A 50mm or so lens that can make room for the mirror and at the same time have a large enough image circle to shift and still cover 56mm x 70mm is too much to ask.

The folks at Zoerk informed me that they could modify a Mamiya 50mm PC shift lens to fit on a P67 mount. However, this lens is designed for a 645, and the image circle, at 97mm, would cover a 6x7 image but would leave room for only the slightest shift (6mm up), and that's assuming no vignetting - in reality who knows if it could accommodate shift at all.