Pyro stain fading under UV
In the past I have used PMK with 8x10 Tri-X film to do my platinum printing. I find that the pyro stain facilitates in the creation of the platinum image. Once I inadvertantly put the vinyl border masking material on the base side of the negative and after an extended exposure I noticed lines on my negative where the masking material was in place. Has anyone else who may be reading this post had this experience? Lately I've taken to shooting with the Toyo CF 4x5 (about 1/3 lighter in weight than my 8x10) and then making enlarged negatives with APHS film (as described by Bob Herbst on his web site). This way I will be protecting my precious original negatives from damaging UV light. I would be very interested in anyone's thoughts on this.
Re: Pyro stain fading under UV
I have observed the same effect. However, unless you plan on making editions of 50 or a 100 prints, I doubt whether it is really worth worrying about. Concievably, you might have to goose the contrast mixture for later prints from the same negative, I guess. It is much more likely that you could lose a negative to an incompletely dried piece of sensitized paper, IMO.
Re: Pyro stain fading under UV
If memory serves Kerik Kouklis made the same observation many years ago on the alt-photo-process list.
Like Clay, I have also observed the same effect. Based on data from a couple of rudimentary experiments my belief is that most of the loss of transmission density ocurrs during the first ten or twenty exposures to UV light, assuming exposure times of 5-10 minutes, and the total effect is quite small. So I agree with Clay that it is probably not something one should worry about.
Sandy King
Quote:
Originally Posted by
clay harmon
I have observed the same effect. However, unless you plan on making editions of 50 or a 100 prints, I doubt whether it is really worth worrying about. Concievably, you might have to goose the contrast mixture for later prints from the same negative, I guess. It is much more likely that you could lose a negative to an incompletely dried piece of sensitized paper, IMO.
Re: Pyro stain fading under UV
Yes, I noticed that effect several years ago. I agree that the change has little effect on the printability of a negative.
