View Full Version : Aperture scale -- different elements.

3-Jun-2007, 02:12
I have an alphax #4 with 241mm Raptar f4.5 elements and 305 mm f6.3 raptar elements that all fit the #4

The aperture scale is marked --

4.5, 5.6, 8, 11, 16, 22, 32

this is for the 241mm.

If I put the 305mm elements in the shutter the maximum aperture is f6.3 falling at the f4.5 mark on the lens aperture scale. So ---

What are the aperture settings for the 305mm? If 4.5 is the 6.3 setting what would 5.6 and the others equal.

Thanks for your help

Ole Tjugen
3-Jun-2007, 03:43
6.3/4.5 = 1.4.

Multiply all stops by 1.4 to get the answer. Hint: 1.4 = one stop.

3-Jun-2007, 17:28
So obvious when you know how :) Thanks Ole.