Converting "angle of view" versus "focal"

[Corrado Silveri]

Just a quick help,
I'm trying to find a quick resource to convert the angle of view of some focal (for 35mm still photography) to the equivalent on the Red 4k format.

Anybody have a quick link or a good formula?

Thks in advance,
Corrado.

[Erik Widding]

Just a quick help,
I'm trying to find a quick resource to convert the angle of view of some focal (for 35mm still photography) to the equivalent on the Red 4k format.

Anybody have a quick link or a good formula?

Just basic trigonometry.:nerd:
The following equations assume a 36mm wide frame for the original angle of view. Where:

A = horizontal angle of view (degrees)
W = width of new sensor (mm)


For a lens with no distortion (flat field corrected, and/or longer focal length):

2 * arctan( tan(A/2) * W/36 )


For a lens with tons of distortion (fish-eye):

A * W/36


A wide angle lens, that has some distortion, will be somewhere in the middle of the two numbers.

[chuck colburn]

Look at the second and third tables listed here.

http://www.panavision.com/tools.php

[Corrado Silveri]

Wow,
thanks guys.

:biggrin: