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el french
20-Nov-2008, 23:18
Is it really necessary if the back has tilt/shift? While I don't have a large format camera, I do have a homemade macro bellows for my DSLR that will focus to infinity. http://img.photobucket.com/albums/v649/etfrench/BellowsSideView.jpg It's mounted on a spherical panorama head that allows the camera (back) to rise and fall. I'm considering adding tilt as well. Will a front tilt/shift add anything that can't be done with back tilt/shift?

Eric James
21-Nov-2008, 00:44
Imagine the cone of light emanating from your lens, and the circle of light it projects - rear tilt will not usurp your image circle; front tilt will. Also: unlike front tilt, rear tilt alters the near-far relationship among objects in your composition. This can be used to your advantage in landscapes to emphasize your foreground in a pleasing or dramatic fashion; conversely, foreground distortion can prove disadvantageous when you can't afford to alter the geometry of your subject.

el french
21-Nov-2008, 01:23
If the camera is mounted on a ball head (or pan/tilt head) and the angle of the lens relative to the subject is the same as if it had been tilted relative to the back, would you get the same image?

This seems to be very hard to verbalize :)

I'll try again, does it matter how the angle of the lens relative to the subject is set? Or how the angle of the back relative to lens is set? I'm assuming the rotation points are at the center of the film plane and the center (entrance pupil) of the lens.

C. D. Keth
21-Nov-2008, 01:54
You would be missing the ability to move the plane of focus without changing the subject's geometry.

In practice, though, you can ignore that and do it with the back anyway, which works with a lot of subjects.

You can also use some front rise in combination with rear tilt and panning down on the head to get the same relationship of lens to film as using front tilt. It's just slower.

el french
21-Nov-2008, 19:47
Thanks for the response. That helps.

jeroldharter
21-Nov-2008, 19:52
Don't forget that you have a regular lens for 35 mm cameras on that rig. Those lenses have relatively limited image circles I think so you might need a proper lens if you add significant movements.

Leonard Evens
21-Nov-2008, 20:25
You can do the equivalent of a front tilt by tilting the whole camera, tilting the back and using a rise/fall/shift on the back. Whether or not you can get the exact same thing would depend on how much you tilted and how much rise/fall/shift your camera was capable of.

el french
21-Nov-2008, 22:28
Don't forget that you have a regular lens for 35 mm cameras on that rig. Those lenses have relatively limited image circles I think so you might need a proper lens if you add significant movements.

The camera is an Olympus e330 with sensor that's half of 35mm format, so it has quite a bit of shift available with a 35mm format lens. With a reversed Olympus 35mm lens designed for the camera, I was able to get around 20mm vertical shift in one direction (40mm total) in landscape mode and 8x magnification. It's not set up for shifting horizontally yet. The primary lens for macro work will be a reversed EL-Nikkor 50mm enlarger lens and I expect it should have more range. I also have a Nikkor 50mm (35mm camera) lens that will focus to infinity while on the bellows. I haven't looked a medium or large format lens to see what registration distances are available. As long as it's more than 45mm I should be able to get infinity focus. I'd be happy to get lens recommendations.

I started the bellows part of the project because there isn't any commercially available bellows for Olympus 4/3rds cameras, especially ones that will do infinity focus. It was only after I had it together that I realized it's almost a view camera, so adding more movements just seems natural.



You can do the equivalent of a front tilt by tilting the whole camera, tilting the back and using a rise/fall/shift on the back. Whether or not you can get the exact same thing would depend on how much you tilted and how much rise/fall/shift your camera was capable of.

Adding a single rotating piece will be much easier :) I want to be able to rotate around the entrance pupil (nodal point) for doing panoramas and this will be practically impossible if the lens has movements also.