For anyone interested the old Press/View Camera rules of thumb are:
Normal = diagonal of the film. Approximately 43mm on 135 format. 150mm on a press camera.
Wide angle = the short side of the film. Approximately 24mm on 135. 90mm on a press camera.
Wide field = the long side of the negative. Approx 35mm on 135. 127-135 on a press camera.
Portrait = the sum of the short and long sides of the film. Approximately 60mm. Usually 200mm on a press camera (that is almost exactly what you get from a 50mm lens on 135 cropped to an 8x10 print, BTW).
Telephoto = Twice (or more) the long side of the film. Approximately 70mm on 135. 250-380mm on a press camera.
You will note that those are all shorter than we normally think of them in 135 format, though the WA as gotten down to about right in recent years.
Once again manufactures's of P&S digitals started using 35mm equivalent focal length because there are no standards for sensor size which can vary from the equivalent of a Minox to an APS negative size from camera to camera. It is simply a way to compare the zoom lens equivalent between disparitent cameras. It has no optical meaning other than that.
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Paul Stenquist wrote:
On Dec 23, 2003, at 8:19 PM, Shel Belinkoff wrote:
Y'know, it's funny how, when using other formats, rarely is it said that an 80mm
lens for a 6x6 is "equivalent" to a 50mm lens for a 35mm camera. When's the
last time you heard a 4x5 user ask "What's that lens in 35mm terms?"
Hi Shel,
I've heard that a lot, and I frequently use 35mm focal lengths as a mental point of comparison. For example, I know that my 127mm 4x5 lens is somewhere around 45mm in 35 terms and my 105mm 6x7 lens is approximately the same as a "normal" 35mm lens. I work in advertising and I've found that most art directors understand 35mm angle of view, so when working in other formats they frequently ask, "What's that in 35mm?" The same is true on television shoots where 35mm lenses are closer to APS or the current crop of digitals in focal length vs. angle of view (because the neg is actually half of what we call 35mm.) The still camera 35mm focal lengths are a reference point for many working pros and their clients.
Paul
-- graywolf http://graywolfphoto.com
"You might as well accept people as they are, you are not going to be able to change them anyway."