Re: FW: UV blocker in TMAX100 base?

Judy,

But on Sandy's original post, the measured density difference (as far as UV
blocking is concerned) is about 1.0. That is 10x exposure time! If the
uncovered part takes 3 minutes to exposure to a certain level, the covered
part would need 30 minutes. That difference would surely shows in the
suggested test.

If the test doesn't show significant difference, however, it means that for
that combination and application, the material doesn't really have much
effect.

Dave S

----- Original Message -----
From: "Judy Seigel" <jseigel@panix.com>
To: <alt-photo-process-l@sask.usask.ca>
Sent: Tuesday, February 24, 2004 5:48 PM
Subject: Re: FW: UV blocker in TMAX100 base?

>
>
> On Tue, 24 Feb 2004, Dave Soemarko wrote:
>
> > To test the actual effect, one could expose a step tablet together with
> > another step tablet covered by a processed, blank-area of TMax film and
see
> > the difference between the exposure need to reach the same density.
>
>
> Actually Dave, testing something like that where the difference might be
> subtle, I wouldn't use 2 step tablets, but cover half the width of one
> step tablet with the material. Step tablets, at least the 2115 I use,
> have variations from strip to strip. Of course sometimes they don't, but
> .... often they do. Using the same strip is easy & (fairly) definitive.
>
> I recently tested saran wrap and a sheet of clear plastic, by the way.
> Both showed same difference...
>
> But speaking of step tablets, Tamara should get one... then she'll know
> what if anything she's doing wrong. For a beginner to judge "dense
> negative," or "deep shadows," or whatever is nearly impossible... In fact
> it's not easy for old timers... development of the film can give
> different colors and the effect very deceptive.
>
> Judy
>
>
Received on Tue Feb 24 21:43:15 2004