Wes Kroninger |
|
Medium format lens equivalency
I want to know does anyone know the 35mm equivalent of a 55,50,45,35mm lens on a 645 camera. I would like to know the equivalence plus how to figure it out on my own.Thanks
March 10, 2003
|
|
|
John A. Lind |
|
Wes, 55mm MF ~= 34mm in 35mm format
50mm MF ~= 31mm in 35mm format
45mm MF ~= 28mm in 35mm format
35mm MF ~= 22mm in 35mm format These are approximate. Because of the difference in aspect ratio between the two formats, there are several valid methods of equating the two that come up with slightly different answers. 35mm format has a 2:3 aspect ratio. 645 has a 3:4 aspect ratio. The methods I know of equate horizontal angle of view, vertical angle of view, and angle of view across the diagonal. I don't bother with the trigonometry involved to calculate all this. Instead, I worry about getting into the "ballpark" and use a factor of 1.6 to convert between the two. Divide the focal length of a 645 lens by 1.6 to get a nearly equivalent length in 35mm format. Multiply a 35mm format lens focal length by 1.6 to get a nearly equivalent length in 645 format. -- John
March 10, 2003
|
|
|
Tony Peckman |
|
Wes, here's an easy guide from Steve Smith's website. Go to "Focal Length Conversion..." at this site, http://lightingmagic.com/camraqa.htm
March 12, 2003
|
|
|
|
Log in to respond or ask your own question.
|
