Enlarging lens to paper distance

[Dan Fromm]

Armin, these are crude approximate answers. Nearly 4x with the 150, 5x with the 135. In other words, a print roughly 360 mm x 480 mm or 400 x 600, respectively, if you go full frame from a 90 x 120 negative.

Cheers,

Dan

[Leonard Evens]

For future reference, the rule is the following. Divide the lens to paper distance by the focal length of the enlarging lens and subtract one. That gives you the magnification at that distance. You should probably make your measurement from the lens board rather than from the front element of the lens for most enlarging lenses.

In this case 800/135 - 1 = 4.93 and 800/150 - 1 = 4.33.

A typical 4 x 5 image is about 95 x 120 mm.