P3D At least one dot

[Tom Deering <tmd@xxxxxxxxxxx>]

>Of course, these three red dots SHOULD NOT BE USED TODAY!  (Is
>that clear Chuck? :-))  But you can put your own dots depending
>on what film speed you use.  I use ASA 100 film almost
>exclusively.  The dots for me would be at 1/100 shutter speed,
>f16 and 15 feet (the hyperfocal distance for f16 is around 8
>feet but that's too close for normal stereo photography, i.e.
>with infinity included in the picture.)

If you wanted to do it mathematically, you could paint the dot at 
13.8 feet.  That would make the 6.9 foot near-point as sharp as 
infinity.

>Another alternative of course would be to carry your digital
>spot meter and your programmable calculator or laptop, but
>that's an entirely different approach to this subject...

Of course, a light meter is standard gear for serious photographers, 
but the laptop is impractical.  Perhaps you could use the spreadsheet 
at home, as I did just now to calculate the optimal focus above.  Or 
you could guess.

On the other hand, if you had your light meter, you might not be 
shooting slide film at *noon*, considering those inky shadows and 
overexposed highlights.

Tom Deering

http://www.deering.org