Matching stereo lenses

[P3D John Bercovitz <bercov@xxxxxxxxxx>]

As a counterexample, I went to an authorized Canon repair station 
to buy a pair of Canon FD 50 mm f/1.8 lens from them.  They had a 
good ton of them on hand taken from dead cameras they'd bought for 
parts.  Some were old-FD and some were new-FD style.  Their ages 
spanned maybe 15 years.  I tested all of them by shooting a grid.  
(I stuck a tag on the grid which gave the SN of the lens I was 
shooting.)  After I got done measuring all the grids on the film 
I'd shot, I found the range of focal lengths was on the order of 
1%.  I picked a pair that were within a couple of tenths of a 
percent but I picked them on the basis of cosmetics since there 
were a lot in that group.  I believe that Kingslake says that the 
lenses need to match within one percent in which case it doesn't 
matter which two Canon FD 50/1.8s you grab; they'll all work.
 
Sicks munce ugo Eye cudn't spel "injuneer" & nau Aye r wun.
 
John B


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