[LargeFormat] Aero-ektar question

[Joseph O'Neil]

>   I've heard variable reports about the performance of these
>lenses. Some report problems with chromatic aberration. The
>published data indicate the chromatic should be well
>corrected in the visible range, I don't know why some lenses
>seem not to perform well.

-snip-
Hi Richard;
         Thanks much.  I have heard of variable reports too, and i figure 
it is for one of two reasons:
         1) Rough handling.  I mena, these things were designed to be used 
in a war after all.   For example, an airpalne takes a flak hit, it might 
not be hard enough to knock even a single lens a wee bit out of collimation 
inside the whole optical assembly.  Or maybe jsut a gorund crew member 
repairing a plane and beign a little rough around the lens?
         2) Not sure which ones, but WW2 was where real use of near 
infra-red films for aerial recon started to come into use.  At the very 
least, red sensitive films.    I cannot prove, but I would wager you got 
the odd lens custom designed to be corrected into the IR range.  If so, the 
expense would be at the blue end of the spectrum.
just my thoughts
joe




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