Best Selenium Toner?

[fschifano]

We've been there with this thread already. Selenium toner has some sort of thiosulfate in it. Usually, the thiosulfate is ammonium thiosulfate and it smells like ammonia. Straight up, KRST concentrate stinks a bit if you stick your nose in the bottle; and unless you're a masochist, you don't do that more than once. Once you have it diluted down to working strength, it hardly smells at all. There's only a very faint whiff of ammonia and it's not all that unpleasant. Now if the Rollie branded concentrate doesn't stink they're probably selling you a less concentrated concentrate, or it doesn't have the thiosulfate, or both. You want to pay more for the "prestige" of the Rollie brand. Knock yourself out!

 

[Vlad Soare]

Rollei's toner doesn't have the slightest smell. I don't know about KRST, as I've never used it, but I have used Moersch MT-1, which releases ammonia and stinks like hell in all dilutions I've used it in (up to 1+30, that is).
The Rollei doesn't even stink in concentrated form. It's most probably a different formula, rather than a matter of dilution.

The T-55 direct selenium toner has no thiosulfates, but does have ammonium chloride, which could be a source of ammonia, given that the solution is probably basic because of the sulfite. On the same web site there are two other selenium toner formulae, none of which has any thiosulfates or ammonium compounds. But these are selenium/sulfide combinations, not straight selenium.

I'd like to find a formula for a straight selenium toner with no ammonium compounds. I couldn't find one yet.

I don't quite understand the part about silver replaced by selenium. Selenium should combine with silver to form silver selenide, Ag2Se. And if some of the silver didn't combine with selenium, then it should remain in the emulsion as metallic silver, just like it was before. What am I missing? :confused:

 

[fschifano]

Apparently at least some of the silver is dissolved and not completely replaced. What else would account for the black colored sludge that's found at the bottom of a used container of Se toner working solution?

 

[RalphLambrecht]

Apparently at least some of the silver is dissolved and not not completely replaced. What else would account for the black colored sludge that's found at the bottom of a used container of Se toner working solution?

Frank

I have no idea but selenium itself looks like that too:

http://en.wikipedia.org/wiki/Selenium

 

[pgomena]

I'm not a chemist, but Ian's statement that selenium replaces silver doesn't ring true for me. If it is a 1:1 replacement for silver, why would intensifying a negative with selenium work? My fuzzy trove of accumulated photo trivia favors the silver-selenide theory of combining the chemical elements. I seem to remember reading that the selenium "coats" the metallic silver and protects it from atmospheric contaminants. This would logically result in the increase of contrast seen in both prints and selenium-intensified negatives. Why the solution contains thiosulphate, I have no clue. I always mixed mine with HCA and used it repeatedly until the bacteria took over. I'll probably use them separately in the future.

We need PE to intervene here and set us all straight!

Peter Gomena

 

[Keith Tapscott.]

Archival protection does not come without color change, I'm afraid, unless you are using silver stabilizers such as Sistan.

However, some toning is always better than none. Rule of thumb is: if you can't see a color shift, you don't have protection.

Sulfide offers more archival protection than selenium even if briefly toned, and you can keep the color change with MGIV-FB so minimal that you need a direct side-by-side comparison to see it.

Using sulfide and selenium in sequence is also a nice option and provides attractive split-toning effects.

It is keeping the colour change as minimal as practical that I would prefer. MGIV FB is my main paper.

Can a sulfide toner be added along with selenium toner in the same working strength solution or do they need to be done separately?

After toning and washing, would it be worthwhile using Sistan as a final rinse before drying?

 

[Jeff Bannow]

Archival protection does not come without color change, I'm afraid, unless you are using silver stabilizers such as Sistan.

Ditto. A lot of people don't seem to understand this point - selenium toner is no magic potion. If the print doesn't change color, it isn't doing anything.

 

[RalphLambrecht]

... We need PE to intervene here and set us all straight! ...

I hope so too, because I'm really interested in finding out why some selenium toners contain aluminum thiosulfate (not all by the way). Unfortunately, Ian did not respond when his first answer was questioned.

I seem to remember from discussions with Ryuji Suzuki that selenium toning progresses much faster when abundant thiosulfate ions are present, but I found no literature reference to verify that yet.

I'm also wondering if it has anything to do with the fact that selenium is difficult to solubilize, which is the reason why you'll find sodium sulfite in selenium toners. This is pure speculation on my part. It may have nothing to do with it.

By the way, working strength KRST contains less than 10% thiosulfate. The numbers quoted in previous post refer to the stock solution. Interestingly enough, published Kodak selenium toner formulas T-55 and T-56 do not contain thiosulfate. Ansel Adams' recipe does!

 

[InExperience]

Hi everyone,

I raised this discussion just to ask between these brand which one, by your experience, is the best selenium toner, and why:

• Ilford Harman
• Kodak Rapid
• Bergger

Recently, I have used last one of the list, but I'm no happy of the results.

Thanks

 

[RalphLambrecht]

Hi all ... Any suggestions for a good Selenium toner for a toning beginner to use. I want to get that "wet Print" look and some extended archival qualities if possible. Not really wanting to get colour if it's possible to avoid it. I would prefer to continue to use Ilford MGIV FB Glossy and Ilford MG paper developer. Thanks ...
Greg

Kodak RST is te only selenium toner I've ever used but, give up your hopes for extended archival stability. You only get that from direct ssulphide toning. Selenium toning needs full toning to extend print life; brief direct sulphide toning will do the same with only an unrecognizable color shift. Toning is done primarily for aesthetic reasons and only secondarily for archival reasons.

 

[pentaxuser]

Hi everyone,

I raised this discussion just to ask between these brand which one, by your experience, is the best selenium toner, and why:

• Ilford Harman
• Kodak Rapid
• Bergger

Recently, I have used last one of the list, but I'm no happy of the results.

Thanks

To that list don't you need to add Rollei RSE selenium toner? Amazingly I was the only one nearly 10 years ago who picked up the point made by Vlad Soare that this is odourless. I even got the poster to confirm this in case I had misunderstood. Still no comment from anyone else at the time and eventually the thread "died" until revived a couple of days ago

This seemed to me to be a major advantage to those whose noses react to what is a pungent smell. In the intervening period of over 9 years I wondered if this was another product that has vanished but, no, Macodirect still sell it.

Strangely enough Macodirect make no mention of it being odourless or even saying that it is "low odour" Could it be that Vlad just had no sense of smell but just didn't realise this? However that would appear to be ruled out on the basis that he mentioned in #27 that he had used Moersch and that had a very pungent smell.

S o anyone else used this Rollei RSE and if so did you find it odourless?

Just in case anyone is thinking of suggesting that I contact Vlad again and ask if he remains of the same opinion( a risky strategy as we know on Photrio ) Vlad has not been seen since 2017

pentaxuser

 

[InExperience]

Thank you for your replies. Then, I will switch to Kodak RST.

 

[Tina Kino]

Would someone be able to comment on the Bellini product (Seltone)?

I'd like to try either this or the Kodak one (or Moersch), and am unsure in regards to the differences between them, apart from the fact that the Kodak concentrate apparently has a super long shelf life..

 

[Raghu Kuvempunagar]

MSDS of this product available at Fotoimpex website lists only Sodium Selenite. It appears that it doesn't contain Ammonium Thiosulphate, at least in substantial amount, like Kodak Selenium toner. It still needs a halide solvent to work effectively and if I were to guess, it might contain small amount of Ammonium Thiocyanate. Of course only Bellini can confirm.

 

[JensH]

My vote for Kodak RST...
By the way, is the concentration of Se the same today like 30 years ago?

 

[Tina Kino]

My vote for Kodak RST...

..for any particular reason?

 

[JensH]

..for any particular reason?

Works well at several dilutions from 1:40 to 1:3, so you can easily control the effect from light change (to remove a green cast) to split toning to full brown or purplish color.
Stock solution keeps very well. And 22 Euro for nearly one liter seems fair.

 

[Tina Kino]

Sounds good @JensH - thank you for elaborating!

 

[mshchem]

I've been using the Kodak product for 30 years. I think Ilford's version is similar. Mixed solutions have excellent shelf life. I have concentrate (glass) bottles of the Kodak product that was given to me by folks clearing out darkrooms, 50 years old still fine.

 

[Bill Burk]

Has anyone tried the Ilford Selenium Toner yet?

I just got a bottle so will have some experience with it shortly. Ilford recommends 1:20 for protective toning without color change, which is how I use KRST so I expect it to “all be the same”. I would get what’s available.

 

[Bill Burk]

I'm not a chemist, but Ian's statement that selenium replaces silver doesn't ring true for me. If it is a 1:1 replacement for silver, why would intensifying a negative with selenium work? My fuzzy trove of accumulated photo trivia favors the silver-selenide theory of combining the chemical elements. I seem to remember reading that the selenium "coats" the metallic silver and protects it from atmospheric contaminants. This would logically result in the increase of contrast seen in both prints and selenium-intensified negatives. Why the solution contains thiosulphate, I have no clue. I always mixed mine with HCA and used it repeatedly until the bacteria took over. I'll probably use them separately in the future.

We need PE to intervene here and set us all straight!

Peter Gomena

I understand it converts silver to silver selenide. And not “all” of it, just a thin layer at the surface (when toned 1:20). I think the Suzuki paper explains that you end up with two images, two different metals, so that if environmental conditions cause one image to fade (probably the silver), there’s a chance the other image (silver selenide) might not. So in that sense protective toning is like insurance..

 

[Bill Burk]

..for any particular reason?

Widely supported in literature.

 

[john_s]

I understand it converts silver to silver selenide. And not “all” of it, just a thin layer at the surface (when toned 1:20). I think the Suzuki paper explains that you end up with two images, two different metals, so that if environmental conditions cause one image to fade (probably the silver), there’s a chance the other image (silver selenide) might not. So in that sense protective toning is like insurance..

During a Tim Rudman course, he produced a print that had been fully selenium toned, then the silver (all of it, I think) bleached out leaving a brilliant orange/brown image. It was beautiful and it took our breath away.

 

[RalphLambrecht]

How can you tell when the HCA solution is becoming exhausted?

I use it only once a session.

 

[koraks]

I think the Suzuki paper explains that you end up with two images, two different metals, so that if environmental conditions cause one image to fade (probably the silver), there’s a chance the other image (silver selenide) might not. So in that sense protective toning is like insurance..

Which is a really weird reasoning if you look at what it means in practice. Imagine the silver-based image would bleach, what you're left with is a lower-density image (after all, the silver is partly gone) and one with a significantly shifted hue (due to the color of the finely divided silver selenide; see @john_s's post above). I.e. you get a faded, severely color-shifted print. Not much of an insurance...unless the only objective is to maintain a somewhat recognizable image, and not so much a print that still 'works' as such.

The rationale I think is supposed to be that the thin layer of silver selenide is supposed to be at the surface of the silver strands that make up the image, and that this is supposed to avoid deterioration of the silver beneath it. This leaves a range of questions unanswered - i.e. to what extent the silver selenide will indeed form a thin layer of sufficient integrity, and against which forms of deterioration of the actual silver this is supposed to protect. As to the latter, mechanisms like bleaching, sulfur-toning and 'silvering out' are rather different in terms of their mechanisms and hence, protecting against these effects involves a range of strategies, although there can be overlap between them such as avoiding excessive moisture.

I don't doubt mild Se-toning works to an extent, but I have severe doubts as to the true efficacy that people attribute to very mild toning regimes.

Btw, note that sulfur works in the same way and is in fact chemically/physically similar to selenium in how it binds to the silver. Just a whole lot less obnoxious! The presence of thiosulfate in a selenium toner may very well constitute part of its protective effect due to disintegration of the thiosulfate over time, which acts as a very mild & slow toner. Similar to basically not washing your FB prints too thoroughly...

PS I use the Adox Se toner. AFAIK it's similar or virtually identical to the Kodak product. In any case, it seems to behave exactly like it.