Richard Lahrson (tripspud@hooked.net)
Mon, 22 Feb 1999 17:59:16 -0800
Sandy King wrote:
>
> Richard Knoppow wrote:
>
> > A caveat. The Weston Analyser uses a Selenium cell. They can have the
> >same problem with getting non-linear that the similar cells used in
> >exposure meters have. When this happens the meter reads right for low and
> >medium light levels but low for higher levels. So any device using a Se
> >cell should be checked to make sure the cell hasn't become degraded. If you
> >pay anything substantial for one you should have the right of return.
> >----
>
> Do Selenium cells degrade from use or does this occur over time
> irrespective of amount of use?
>
> Sandy King
Greetings everybody on Alt Process!
Let's assume, for my argument, that the cell is reads low at high
densities, as Richard says. If you are checking against a step wedge,
you will, at least, be aware of the amount the cell is off, and hopefully
be able to adjust hegative readings accordingly.
Though, of course, one would prefer one right on. Mine is.
Rich Lahrson
tripspud@hooked.net
This archive was generated by hypermail 2.0b3 on Sat Nov 06 1999 - 10:06:53