Re: physiology vs. sensitometry

Steve Avery (stevea@sedal.usyd.edu.AU)
Wed, 12 Jun 1996 13:33:01 +1000

The following mail bounced (originally from MJC5@EMAIL.PSU.EDU)...

(Mike, I changed your subscription address as it appears your domain
name has changed...)

----------------------<included message follows>----------------------

Mike writes: >we are trying to recreate that mental image."
>
Terry replys:I know what you say is theoretically correct and I had always
believed it myself but it is a misconception.

and:

>so I asked Richard if he perceived the scene in the way that I did. He did. The
>only way one could see the detail under the arch was to walk under the arch and
>allow the eyes to adjust to the dimmer light there.

It sounds like the highlights of the scene exceeded your eyes
ability to open its pupil while trying to scan the darker parts. The
contrast range must have been indeed large. It also sounds like a very
exciting place to make images at.

>So when printing that scene to express the full range of perceived tones from
>the point at which the camera was placed, the detail under the tower should NOT
>have been included.

agreed!

>I seem to be defending a truism here against attack from all sides.

As should be the fate of all good truisms! I can duplicate the
visualiztion method you are using by looking at the scene without shifting
my eyes to "scan" the scene. Kind of like making a quick snapshot as
opposed to a slow scan that I normally use.

I think I'm going to experiment with this a bit. Thank you.

- Mike -

mjc5@psu.edu