35mm format lens used in Super16 format

Paul Bruening · January 9, 2008

Oi! How many times will we go over this. A 50mm lens is just that: a 50mm lens. Its coverage characteristics have nothing to do with its angle of view.

Some characteristics will be the same. But not all. It can't all be the same. The elements are different. A 50mm for 16mm does not have to cover as large a frame as one made for 35mm still frame. When I say this, I'm not referring to theory. Theory says that a 50mm is a 50mm. But when you look at the actual lenses, when you consider the compromises employed by the designers, they aren't the same. A 50mm for 16mm will vignette on a 35mm still frame. Sure they're both 50mm. But the designer doesn't have to include those bigger elements since the 16mm frame doesn't use the larger area. In practicality, a 50mm isn't always the same. It is probably correct to say that from our perspective, the lens user, there is no significant difference. Maybe, it's only an issue for the designers and engineers.

John Sprung · January 9, 2008

As I understand it, "normal" means that the image most replicates the optical-lensing characteristics of the human eye. No lens does that perfectly, ....

I've heard that a lot, too, and always thought it was a really weird idea. Cinematography and human vision -- at least my vision -- are nowhere near alike.

Cinematography has frame lines and composition. Just looking around the real world, there's stuff in front of me that I can see, and stuff behind me that I can't see. But I'm not aware of the transition between them. There certainly aren't sharp rectangular frame lines. Even if I turn around quick like a dog chasing its tail, I don't see the frame lines, let alone the green EXIT sign.... ;-)

Cinematography uses one lens and gives us a wide variety of DOF choices. The human eye has a more limited range of stops, about f/2 to f/8, controlled by our auto-exposure system, which relies on changing the "speed" of the retina for most of its dynamic range. One eye by itself usually has quite large DOF, but our atteniton is restricted to a much narrower range of distances by the fact that we have two eyes. Hold your hand out in front of you at arm's length, and shift your attention between it and another object maybe 10+ feet away. You'll see one of what you're looking at, and a double image of whatever is at the other distance. Very different from film.

-- J.S.

Erkan Umut · April 4, 2008

I'm not sure what "F/50mm" means, I think you just mean a 50mm lens.

Your rental house was wrong. 12mm and 6mm are different focal lengths. If you want a 6mm view on a Super-16 camera, you use a 6mm lens. If you put on a 12mm lens, you get a 12mm view. It doesn't matter whether it is a Super-16 or 35mm lens -- that only affects lens coverage, i.e. a Super-16 lens image will vignette on 35mm. The focal length is the focal length, only the view changes depending on the format.

So if you want the view of a 12mm lens on a 35mm camera, you'd use a 6mm lens on a 16mm camera. The only difference between a 12mm lens made for 35mm work and a 12mm lens made for 16mm work is not the field of view, it's that the image from the lens made for 16mm might vignette on 35mm because it's not large enough.

Maybe the rental house misunderstood what you were trying to achieve.

Lens for 35mm format - Focal length: 12mm - Angle of View: 90°

Lens for Super16 format - Focal length: 12mm - Angle of View: 64°

When we compared the dimensions of these two formats, we see that the results are similar.

I also noticed that the angle of view of the lenses for Regular 16mm format are about half of the ones for 35mm format in same focal length. It shows that 12mm focal length gives the similar results in both format...