Re: [Leica] Re: Re: Focus thread

[Martin Howard <howard.390@osu.edu>]

Jim Brick jotted down the following:

> Hey... I just work here. I don't make this stuff up!!! But I have to deal
> with it daily.

Jim, many thanks for having the patience to exlain this to a dimwit like
myself!! ;) ;)

I get the bit about why scene is important: If I understand you correctly,
and remember by perceptual psychology classes correctly, what you're saying
is that focus for humans is guided by the fact that we know that we're
looking at a book-case made from plexi-glass: it just happens to be made
from plexi-glass, but we know something about bookcases and therefore
understand that they are convex in certain places, concave in others, and
make (correct) assumptions (based upon the experience of being animate
agents living in a three-dimensional world) that guide the focussing of our
eyes.

Now, I could go into saying that I understand how this explains grave
focussing errors (hunting) on the part of AF systems, but not how you can
get higher lp/mm from MF lenses compared to AF lenses, but I won't... ;)

M.
 
- -- 
Martin Howard                     | "Ice cubes would melt in her mouth.
Visiting Scholar, CSEL, OSU       |  That's how cold she was."
email: howard.390@osu.edu         |        -- Radio ad for new TV show.
www: http://mvhoward.i.am/        +---------------------------------------