lenses

[Michele]

Whats the difference in field coverage between 4x5 lenses and those made for SLR's?

[steve simmons]

slr lenses will not have an image circle any larger than the film size. View Camera lenses will have an image circle that is larger to accommodate movements.

steve simmons
view camera magazine

[Scott Rosenberg]

hi michelle... there's a very helpful article about lensesw for large format photography here. of particular note is the section on image circle.

[Ralph Barker]

Just to clarify, 35mm SLR lenses, along with those designed for 35mm rangefinders and medium format cameras, may have image circles somewhat larger than the format they were designed for, but that isn't generally a design criteria of primary importance. For example, some Hasselblad lenses have sufficiently larger image circles that they can be used with the ArcBody and FlexBody cameras from Hasselblad. Similarly, some older medium format lenses have been adapted for use on view cameras to provide circular images for artistic reasons. The image outside the area of the format for which the lens was designed is usually of lesser quality, however.

In contrast, many view camera lenses, as has been noted, are designed with larger image circles to allow for view camera movements. How much larger the image circle is depends on the use for which the lens was intended.

[Ernest Purdum]

Michele asked about "4x5 lenses", so we should probably point out that the 127 and 135mm lenses commonly found on Crown or Speed Graphics and similar cameras have little to no excess coverage, since these cameras have minimal movement capability.

[Armin Seeholzer]

Steves comment is not fully correct I have the 28mm shift lens from Nikon wich has also a larger image circle for the shift ability and it is a 35mm lens!

[steve simmons]

Th PC lenses are exceptions but these are specialty lenses used by only a very small number of people.

steve simmons

[Robert A. Zeichner]

It should be pointed out that there have been large format SLR's manufactured in the past and there is even one on the market now from Wisner. Some of these cameras had provsion for rise. I'm certain the image circle of lenses made for these cameras was over the minimum required for the film size. The image circle for lenses designed for hand cameras without any provision for shift, swing or tilt is often best kept to the bare minimum necessary to cover the target with a sharp from corner to corner image and no more. This, because it is necessary to keep reflections within the lens box to a minimum. This is particularly true in reflex motion picture cameras, where it is not possible to paint everything flat black. Many SLR lenses have rear "matte boxes", light baffles that actually cut off projection to prevent flare. These are necessary when doing close up work because the image circle grows as you move the lens further from the film to focus on near objects.