Selenium Toning Negatives

[brian steinberger]

I'm curious as to if anyone selenium tones their negatives almost all the time. Besides the fact that it's a great intensifier, what are the archival benefits as compared to not selenium toning negatives?

[paulr]

to get significant archival benefit, you have to selenium tone the negatives thoroughly .. .for all practical purposes you have to do it to complete conversion of silver to silver selenide. this would mean toning all your negs to a high degree of intensification, which doesn't give you much flexibility to selectively intensify your negs and still get consistent protection from oxidation.

selenium is a nice intensifier in general, if you're only looking for N+1 or maybe N+2 results. It's not as dramatic as other intensifiers.

gold and sulfide toners are generally more useful for preservation (a lot of research has been done on microfilm).

but how long do you need to preserve your negatives for? unless you store them in a contaminated environment, they're probably going to outlast you by a long time. archival toning is usually reserved for negatives that are used as archival documents.

[neil poulsen]

There's a few threads in the archives on selenium toning negatives. If you need some punch to highlights, this can do the trick. One can pull about an additional stop, like from N+1 to N=2.

[Brian Ellis]

The only reason to selenium tone negatives that I know of is to increase contrast (overall or locally). Hopefully that isn't something that needs to be done very often, if it did then you'd be better off to rethink your exposure index, processing times, etc. rather than solving the problem by consistently selenium toning your negatives.

I've never heard of any archival benefits from selenium toning negatives. Film is inherently very archival if it's properly processed, washed, stored, etc. I remember John Sexton (who IIRC was working for Ansel Adams when the idea was first tried) saying they had some concerns that it might have adverse archival effects but that so far there haven't been any.

The idea of selenium toning negatives came about at a time when graded papers were much more common than they are today. If you're trying to increase contrast of a print today I think it's normally easier to do that at the printing stage with variable contrast papers in the darkroom (and infinitely easier to do in Photoshop if you print digitally) rather than trying to get the contrast increase by alterning the negative, especially considering that there are some risks of damaging the negative when selenium toning it if you aren't careful.

[paulr]

"I've never heard of any archival benefits from selenium toning negatives."

when toned thoroughly enough it can prevent oxidation and staining. you're right that negatives are stable enough for most people's needs when stored properly. but additional protecction is often warranted for certain kinds of archival documents. there's a bit of research on the topic mentioned in this thread: http://www.largeformatphotography.info/toning-permanence.html

"there are some risks of damaging the negative when selenium toning it if you aren't careful."

i agree with this ... one time i mustn't have been careful, and damaged a batch of negatives. at the time i was using selenium toning for all my n+ negs. others on the board have said they never had problems with selenium, so it must have been some detail that i was sloppy with. but the risk is there.