Differences in format perspectives???

[stradibarrius]

If a photograph was taken with a 4x5 camera and then the exact same photograph, with equivalent focal length lens, was taken with a 35mm camera would there be a difference in the look or perspective of the image from the two cameras?

If the answer is yes would there also be a difference between the 35mm and a 6x7 image?

[Greg Davis]

Yes, there is a slight difference. The 35mm frame would look slightly wider than the 4x5 if doing a horizontal image with the same items arranged on the top and bottom edges. The 35mm frame is slightly longer and would include more info from left to right. 6x7 is the same shape as 4x5, or very close to it, so they would look nearly identical. I set up a 35mm camera with a 50mm lens next to a 4x5 with 150mm lens for a demo with my students to demonstrate the idea of different focal lengths on different formats to achieve the same view. The 150mm lens was slightly wider in perspective because the actual equivalent should be 165mm in relation to a 50mm lens on a 35mm frame.

[keithwms]

If the images are taken with a lens producing the same field of view? Notwithstanding tonality, resolution and effects due to lens design and aspect ratio and such, there will be no difference.

[Denis K]

The perspective of an object in a photograph is only dependant on the position of the camera, not the size of the negative or the focol length of a lens. However, the field of view of the picture IS dependant on the film size and focal length. In other words, for a 35mm picture to contain the same subject space as a 4x5 picture, the focol length of the lens must be different.

[stradibarrius]

Denis, you are correct and I should have said FOV rather than perspective. I know that a 50mm in 35 format is not the same as 50mm in a 4x5 format. In 6x7 format a 100mm is roughly equivalent to a 50mm in 35 format. I am not sure what the "normal" focal length is in 4x5, 165mm?, when compared to 35 format????
But to get back to the question, if the shots were taken with from the same tripod giving the same "perspective" would the 50mm lens in the 35mm format give the same FOV as the 165mm lens in the 4x5 format. I think you are telling me the answer is yes????

[keithwms]

Yes, except for the difference in aspect ratios.... FOV is often defined along the diagonal of the frame.

[Greg Davis]

Yes, except for the difference in aspect ratios....

That difference in aspect ratio would translate to more stuff on the left and right edges of the frame on 35mm film (or top and bottom if you do a vertical shot). This is because the 35mm frame is a slightly longer rectangle than 4x5 film.

[ic-racer]

35mm and 6x9 have a very similar aspect ratio. A good rule of thumb for equalizing DOF between formats (for lenses of the same angle of view on the film) is to keep the absolute aperture (in millimeters, not f-stops) similar.