Rapid selenium toner on film

[lsaavedra]

Which are the beneficts of using rapid selenium toner on film? Kodak

says on his technical publication that it may cause a slight contrast

increase but nothing else. I'm not interested in raise the contrast

of my negs but I could live wit it if I get some protection effect or

increased durability as in prints. Thanks in advance

[simon_park3]

hi - it acts in direct proportion to the amount of silver on your neg

- so hightlight (dense) areas will go a lot more dense - raising

them up a 'zone' or two. Midtones will be slightly stronger and

shadow areas will not benefit. this may make your neg slightly

easier to print if it's thin. With a dense neg it could just mean

unprintable highlights...if your just after better neg archivability go

for a weaker dilution but for longer(as with prints) but to be

honest properly fixed/washed negs will last for 50 years - do you

want your negs to live for ever?!

[pat_wilson1]

50 years? They'll last a lot longer than that!

 

Not to hijack the thread, but anyone try selenium on PMK negs? Does it damage the stain?

[dk_thompson]

A better way to do this would be to use a sulfide toner or a polysulfide toner, if protection is what you're after. If selenium is used--you need to use fairly strong dilutions of it, which will cause an increase in contrast, and has been proven to be not as effective as the sulfide toners. This is pretty much the way it's done in archival programs and microfilm reformatting--with brown toner or a proprietary polysulfide toners.

 

Fwiw though--how long your negs lasts depends on several factors, not the least of which the type of base material and the relative humidity and temp they're stored at. Unless you're using polyester based films, 50 yrs is a good rough estimate for acetate based b&w films in a "normal", albeit cool/dry type room. BUT--the image itself can still suffer from poor storage materials or atmospheric pollutants.

 

So in an ideal world--you'd tone the neg and store it in a controlled, cool/cold/low rh environment for it's entire life. BTW--50 yrs would be for an acetate b&w neg stored at 68 degrees F and 45% RH or less. If the humidity increases, the life expectancy drops --same with higher temps. You can roughly double the life for each ten degree drop of temp. But humidity is a bigger factor in b&w, and you need to keep it as low as realistically possible. Polyester based films fare much better at normal room temps. So, just like prints they need to be toned for extreme long term use, and just like prints again, sulfide toners work best.

 

Hope this helps & makes sense. my opinions only and not those of my employers.

[andrew_oneill]

I've used selenium toner to intensify negatives that were developed in pyro developers including pyrocat-HD. Doesn't affect the stain at all from what I could tell.

[doremus_scudder1]

I have tried to locally intensify pyro-developed negs with selenium toner 1:2 and did notice a difference in the stain. The selenium definitely removed the stain on the areas I tried to intensify with the result that the removed stain about equalled the amount of intensification, effectively yielding zero change.

 

I have heard that an after-bath might restore the stain (or even treatment in spent developer) but have not tried it yet.

 

Hope this helps.

[gauthier]

For conservation purposes, I would agree with DK Thompson that sepia (sulfide) is the way to go. For negative intensification purpose (useful, for instance, if a neg is weak or if you want to make a normal neg more useful for alt processes) about 5 minutes in a 1:2 selenium bath will do the trick.

 

Also note that you can combine both. Sepia tone first, then use the strong 1:2 selenium bath for intensification.

[amul]

I thought the whole point of selenium 1:20 was that it's an archival process that worked with both prints and negs. I've also read in various sources that you can mix selenium with permawash and use them in the same step.

[dk_thompson]

they did recommend selenium for a long time--still do in some publications--but as far as preservation goes, most places use brown toner or IPI silverlock for microfilm. here's a link or two if you're interested:

 

http://www.oclc.org/preservation/microfilming/duplication/silverlock.htm

 

 

http://palimpsest.stanford.edu/byform/mailing-lists/cdl/1993/0376.html

 

http://palimpsest.stanford.edu/byorg/abbey/an/an12/an12-5/an12-507.html

 

 

FWIW--I used selenium for several years as a post-treatment on Kodak's SO-132 duplicating film. This particular film had some longevity problems that caused alot of archives to quit using it altogether back in the mid 80s, coupled with it's incompatibility with duping older glass plates. The film could stain and shift in density over the longterm--and Kodak came out with several versions of it, but in the final processing sequence, it was pretty much mandatory to tone it with brown toner or selenium. And, if selenium was used, you did a prewash, then toner, and did a full 20-30 minute final wash and no hypo clear was used in this sequence. The negs I've made, at their oldest, would be about ten years old now. I work in a lab/studio in a historical museum with ties to an archive nearby. From that collection, there are negs made on this film dating back to the 50s and they haven't fared too well. I believe they quit using the film back in the late 70s. Moot point now, it was discontinued 2 years ago. but microfilm is *the standard* for records storage and reformatting in archives, so these studies are pretty relative when you talk about longevity of b&w film.

 

Hope this helps, as always:Opinions expressed in this message may not represent the policy of my agency.