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Re: [tech-3d] f/stop calculation

  • From: Brian Reynolds <reynolds@xxxxxxxxx>
  • Subject: Re: [tech-3d] f/stop calculation
  • Date: Wed, 19 Apr 2000 14:32:13 -0400
Dennis M. Hanser wrote:
> Anyone have a reasonably accurate and reasonably easy way to 
> calculate the actual physical size of an f/stop?
> In particular I am looking for the sizes in mm for a 100mm flat field 
> lens at f11,  f16,  f32, and f64.
> 

aperture = focal_length / focal_ratio

If the lens has a 100mm focal length then the aperatures are as
follows:

focal_ratio aperture
----------- --------
11          9.0909
16          6.2500
32          3.1250
64          1.5625

-- 
Brian Reynolds                  | "Dee Dee!  Don't touch that button!"
reynolds@xxxxxxxxx              | "Oooh!"
http://www.panix.com/~reynolds  |    -- Dexter and Dee Dee
NAR# 54438                      |       "Dexter's Laboratory"

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