P3D Re: Hyperfocal Tables

["Dr. George A. Themelis" <DrT-3d@xxxxxxxxxxxxxxxxxxxxxxxxxxx>]

>Solving for C, the Ilex lenses results in a CoC (C) of 1/1000
>(.001 inch) of an inch. Later with the DW lenses they increased
>the CoC to 1/750 (.00133 inch) of an inch.

YES Gabriel!  You his this on the head!  Sorry I had not read your
posting very carefully.  Clearly, investigative work of first
rate by Gabriel.  Well done!

>I agree that technically, on the considerations for selecting a CoC, but
>I still think it was changed for a non-technical reasons (marketing!).
>I suspect they changed it because of competition from Kodak!

In 1951 there was no Kodak (Kodak showed up in 1954).  Realist was 
still "the only game in (USA) town".  I don't think that marketing 
was behind that.  Some cool thinking perhaps... Do we need 1/1000?
Maybe not.  Then let's relax it.  I personally think that this was 
a reasonable decision.  I also think the change took place when
David White lenses were used.  So it had nothing to do with going
from Ilex lenses to David White.

>A few months after my original post, I did by a copy of the
>newsletters from Dalia and noticed this reference but by then the
>thread was old and didn't bother posting it and besides it didn't
>shed any new insight from what I originally posted.

Yeap!  More good investigative work from your side.

>P.S. It's okay Dr.T, like they say, everything in 3-D has been
>     done and said already, and in this case was probably solved
>     (or actually solved) along time ago, before any of us! ;-)

Could not agree more!

>P.P.S. Please reserve a copy of your new book for me!

Gotcha! :-)

George

PS. 3 am and I am still up finishing my notes for the 3 workshops!  
    Work tomorrow at 7 am.  Not much sleep tomorrow either.  Then 
    leave for Green Bay to be there early afternoon... I will be a 
    wandering ghost... The guy with the black eyes is DrT... 


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