Shifting

Discussion in 'Classic Manual Cameras' started by craigd, Jan 30, 2011.

  1. I've been interested in tilt/shift lenses for a long time, but the budget has never been there to acquire one. Recently, however, I realized that the old Nikkor 35mm shift (no tilt) lenses are surprisingly affordable even compared to the Nikkor 28mm shift lenses. While the tilting ability would be nice too, shifting is useful by itself (the two are really unrelated functions, it's just convenient to package them together), so I decided to take the plunge.
    Shift lenses are often referred to as "perspective correction" lenses, which I find misleading. It is a fair description of the reason people want them, but it is not actually a description of what the lens does (in the same sense that a "zoom lens" is a lens that zooms). In reality, a shift lens is simply a lens that casts a larger than normal image circle and allows you to choose (by rotating and shifting the lens) what part of the image circle you want in your picture. It is not correcting perspective at all (which would imply that the lens was somehow doing something by itself to correct it without the camera being moved); it just liberates the frame from being centered around the lens axis. To keep your verticals vertical, the camera still has to be level. The shift effect can be simulated quite effectively by shooting a much wider non-shift lens and then cropping to a rectangle that was not centered in the original image, though of course you lose resolution doing it that way. (Tilt, on the other hand, cannot be simulated by a conventional lens.)
    In the course of some research online I learned that the 35mm PC-Nikkors basically come in three types. The early f/3.5 version, introduced in the early '60s, is not as desirable as the later f/2.8 versions because of an unfortunate lack of foresight in the physical design of the lens: the part of the lens that shifts extends far enough back that it can bump into a Photomic finder, whereas in the f/2.8 versions, the part that shifts is far enough forward to clear the finder. There are two f/2.8 versions, the first (introduced in 1968) with a chrome knob for controlling shift, the second (introduced in 1981) with a black knob. The black-knob version is said to have an improved optical formula that produces sharper images with less vignetting.
    So I ordered a black-knob PC-Nikkor 35mm f/2.8 from Adorama. When it arrived, I put it on a Nikon F2, loaded the camera with Velvia 100, and headed out to experiment.
    1. Nikon F2 with PC-Nikkor 35mm f/2.8
    [​IMG]
    Since it seems to be mostly 24mm and even 17mm tilt/shift lenses that get the most attention today, I wanted to see if 35mm would be wide enough. What I found is that it's fine, at least for the kind of architectural pictures I like. I don't really care for architectural shots in which angles are grossly distorted, which is what happens when you shoot buildings with any kind of ultra-wide lens.
    It is often said of shift lenses that they must be shot tripod-mounted. I can certainly agree that a tripod would make it easier to keep the camera level, but it really isn't that hard to get good results while shooting hand-held. Just keep your eye on the verticals!
    2. City Hall, Mountain View, California
    [​IMG]
    3. Center for the Performing Arts, Mountain View, California (City Hall on the right)
    [​IMG]
    4. High School Way, Mountain View (which has no high school anywhere near it)
    [​IMG]
    There is, of course, more that can be done with a shift lens than this. Galen Rowell once created a very dramatic image of a skyscraper by shooting from a helicopter with the lens shifted the "wrong" way. These shots represent only a first acquaintance with the lens and the pleasure found in obtaining the desired results from using it in the "proper" way (albeit sans tripod).
     
  2. Nice work, Craig. Having spent much of my photographic life playing around with large format cameras, I miss the lens movements when I pick up a 35mm camera. I guess that's one of the reasons my colleagues in the '60's referred to them disparagingly as "hobby cameras"...
    Lens shift in 35mm format certainly goes some way to correcting the problem of distorted perspective. I was tempted to go the tilt/shift way a while ago, but the expense and the anticipated infrequency of use deterred me. I still have the odd 5x4 camera, if I feel the need. In the meantime, Photoshop provides all the perspective control I need, and it's pretty much the equivalent of easel / lens board movement in enlarging. I would like a "tilt" ability for DOF control, mainly to increase DOF as intended, though most users use the facility in reverse, to minimise DOF. Oh well... That's a very handsome outfit, and the saturation and crispness of the images is terrific. Thank you for a stimulating post.
     
  3. I agree that a shift lens does not "correct" perspective. What it does is help us distort perspective.<br>Take "City Hall", for instance, and see how with straigthened lines, it appears to be wider at the top. Expanding, ready to burst.<br>So the problem with "distorted perspective", Rick, is created by the use of such lenses. Not solved by using such lenses. Perspective left to itself cannot be incorrect. The perspective presented in these pictures however is one you cannot, not ever, encounter in real life.
     
  4. Well, most photographs, in one way or another, show things in a way that is different from how our eyes perceive them. I don't think the goal of photography is to show us things as we see them, and that's just as well, because it's impossible. What is possible, to some extent, is to choose what kind of unreality to have in your pictures.
    I think we are all familiar with the problem of buildings looking like they're falling over backward because they were shot with a wide-angle lens tilted upward. Keeping your lens level and shifting it upward is one way of avoiding that. The result is not a perfect solution but it is, at least when employed well, a less annoying type of distortion.
    I included the last picture (High School Way) as an example of using a shift lens for non-architectural purposes. With a non-shift lens, I would have had to tilt the camera up to frame the shot like that. Because of the camera tilt, the building on the right and the distant tall trees on the left would tilt toward the center, whereas they stand straight in reality.
     
  5. Oh, but i do a agree with your statement that a shift lens does not "correct" perspective, Craig. That was my point.<br><br>You can over-'correct' though, and had you left a little bit of lean, the image would have looked a bit more convincing.
     
  6. Good crisp results, Craig. I have the silver knob one here:
    http://www.photo.net/classic-cameras-forum/00U6uW
    Although it's a bit bulky for everyday shooting, I just love the super smooth Bokeh of that lens and sometimes just use it straight for that feature.
    00Y8Jm-327147584.jpg
     
  7. I must admit I'm pretty ignorant about shift lenses. I've seen how you can adjust on a monorail all sorts of perspective oriented, but I can'T see how the shift lens works. This has gone a waysin helping me understand. The image size is larger and allows the user to select less of the image which is then less likely to distort. Can you see this in the finder? I would of benefitted if I could see the shot without the shift and then with the shift. Lovely pictures none the same Craig and I suspect the 28mm would have distorted the buildings somewhat, that I don't see here!
     
  8. It works how you say it does, Chuck. You keep the camera level, and the verticals will remain parallel. But the the top of the building is cut off. So what you do instead of tilting the camera up (and create converging verticals) is shift the lens up. That brings the top of the building back in the picture (but you lose the foreground), while keeping the camera level, the verticals parallel. And that works because of the big image circle shift lenses produce (if not that bigger image circle, you would shift the image off the film). You can of course see what the camera will capture through the viewfinder, yes.
     
  9. Gorgeous camera Craig. Your F2 seems to have survived the war quite well. I really like the burgundy and white checkerboard underneath it. Having spent much of my early career doing architectural work, I really notice whether lines are straight or not. I understand why you might want to let the perspective show a little, but the editors of the mags I was shooting for would never allow a shot to go through with obvious keystoning.
    The other great feature about the Nikkor lenses is there is really no barrel distortion. So even if you do shoot with some angle showing, it won't be bowed. I used to use the 28mm PC all the time, when not shooting with a SW/CM or view camera. It is a very helpful lens in some situations, but I would have been in heaven with all the software tricks we have today for stitching and PC.
    I think the term I would favor over "correcting" the perspective is "controlling" it. When doing architectural work, you get a real sense of the struggle over perspective, straight lines, lighting, etc. It becomes almost a battle, and you're trying to control the perspective, lines, etc. Nice work, and you've demonstrated how useful the 35mm PC can be.
     
  10. It is funny how there are so many "definitions'' of perspective, even from supposedly authoritative photographers (Moose Peterson and David Noton come to mind among those I have recently read about). Perspective is actually decided by the position of the camera, nothing else. That alone decides how the different objects in the image relate to each other. Therefore it should be clear that perspective control lens does not in any way control or correct perspective. You can get the exact same image by shooting with a wider angle lens and then cropping a part of that image (usually keeping the top part, for rise). How could that change the perspective? Maybe a better term would be to call them parallax control lenses? I happen to have three different PC lenses (28, 35 and 80). Nice tools. And I agree with Q.G. that it is often better to leave just a hint of converging verticals in the image rather than shift it all away. It is most obvious in the first image above, much less so in the other two.
     

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