At 08:49 AM 2/23/2004, you wrote:
>In testing TMAX 100 film I have come across a curious phenomenon. It is
>the fact that when reading UV density with my densitometer (which reads in
>a fairly narrow band around 373nm) there appears to be a base UV blocker
>of a little more than log 1.0.
>
>I am wondering if any on the list are currently using TMAX 100 for
>alternative printing in which exposures are by UV light, and if so have
>you noticed any difference in printing times between TMAX 100 and other films.
>
>So far TMAX 100 is the only film I have tested that has this kind of UV
>blocking in the base.
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.
Bruce E. Kahn, Ph.D.
Imaging and Photographic Technology,
Materials Science and Engineering
Rochester Institute of Technology
70 Lomb Memorial Dr.
Rochester, NY 14623-5604
bkahn@mail.rit.edu
(585) 475-7219
http://www.rit.edu/~bekpph/
Received on Mon Feb 23 21:15:53 2004
This archive was generated by hypermail 2.1.8 : 03/02/04-11:35:09 AM Z CST
