On 24 February 2004 Bruce Kahn wrote:
>
>Sandy, you are correct that T-Max appears to have a UV absorber in it.
>
>I am currently teaching a course on 19th Century photographic
>process. A graduate student noticed some interesting differences
>between different negatives (T-Max and Ilford FP-4). I did some
>quick absorbance measurements for some of the materials that
>students were printing using a spectrophotometer. I have posted
>some of this data at
><http://www.rit.edu/~bekpph/historic/films.jpg>. As you can see,
>T-Max absorbs UV from ~ 320-410 nm. There is a fairly narrow UV
>transmission window at about 320 nm.
>
Certainly nice to have confirmation of of the UV blocker in this film.
My hunch from looking at your data is that this UV blocker would have
more impact on the colloid processes (which are most sensitive to UV
radiation below 400 nm) than it would on the iron processes (which
have a lot of sensitivity above 420 nm). Also, one would expect that
the impact would be greater with UV sources such as BL and BLB tubes
and NuArc platemakers (which put out most of their radiation below
420nm), than with a tube such as as the Super Actinic that peaks at
around 420nm.
Sandy King
Received on Tue Feb 24 11:53:38 2004
This archive was generated by hypermail 2.1.8 : 03/02/04-11:35:09 AM Z CST
