And in the light of morning and a few cups of coffee I realize that I
didn't forget to open up since I was shooting in manual mode and all
exposures (which were correct) were taken at the same shutter speed. It
was just dumb luck that I nailed the focus while focusing at f/8.
I've also realized that maybe I tried to set myself a too difficult goal
for aging eyes. I was trying to shoot everything at f/2 from
approximately 1 meter (just outside the 85/2's min. focusing distance of
0.85 meter). The DOF for 85mm at one meter and f/2 is only about 16mm.
Big, big premium on focusing being absolutely spot on.
I also realized that I don't have to involve the MF Zuikos since I can
use the AF Tokina and get direct MF/AF comparisons. And for testing the
effect of focusing with slower lenses I can just close the aperture down
and focus while holding the DOF button down. It also has the advantage
of everything shot with the same lens.
I have to think about this some more. What makes a reasonable test of
MF focusing capability?
Chuck Norcutt
Chuck Norcutt wrote:
> As I'm re-reading my own note I noticed that the best possible
> explanation for the sharpest focusing occurring at f/8 is that I
> probably forgot to open up again to shoot at f/2 after focusing. The
> shot was most likely taken at f/8 with lots of DOF.
>
> Oh, well. Not very good science here.
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