• Welcome to Photrio!
    Registration is fast and free. Join today to unlock search, see fewer ads, and access all forum features.
    Click here to sign up

Selenium intensification of negs

Jarvman

Member
Allowing Ads
Joined
Sep 9, 2006
Messages
791
Location
Cardiff, Uni
Format
Multi Format
I know this is probably a topic that's come up a thousand times before but I'm having trouble trying to print a flat neg even at Gr 5 on Ilford Multigrade! There's plenty of detail on it. It comes up great in lith but its just 'pleh' on B+W paper. I was thinking of intensifying the neg with selenium toner. having never done this before could anyone give me any tips on doing so? It says in 'the negative' to use Kodak Selenium Toner 1:2 with hypo clearing agent. Seems pretty strong. Shall I go ahead and do that? Will try it with something duff first.
 
Yep, you could go ahead with that recipe. There's not much risk of overdoing it, it's going to be a relatively minor change anyway. As with any toning exercise, it's wise to test first on something unimportant and to have an untoned reference to look at as you go.

As an alternative that may give you what you want: you could also make another print but deliberately overexpose it by a stop or so, and bleach it back (farmers). That will introduce contrast... and preserve the pristine state of your neg. I mean, if your neg is nice for lith then why change it if you don't have to....

If grade 5 isn't giving enough pop then I guess you misexposed the shot? Is it too thick or too thin overall? If the former then bleaching the neg may be a better option. The change you get from Se is quite minor, and really only makes much of a difference if the starting neg is well exposed. It's definitely not a way to save a neg, in other words. I mean, best case, it's probably going to give maybe a half grade or so of extra contrast if the neg was properly exposed in the first place. I only tone my negs if they are already really close but just need a tiny bit more.
 
I've read similar instructions. KRST 1:2 or 1:3 for 5-10 minutes. Diluting with hypo clearing agent has me confused, however. I know this has been recommended in the past, but since KRST contains some fixing agents, it might be better to dilute it with water and follow with the hypo clear and a good wash. Certainly no harm will come of it. Be aware that this treatment is recommended for properly exposed but underdeveloped negatives. Most intensification will happen from Zone V upwards. If the negative is flat overall, you'll just get a denser negative. You might test it on another similar negative first. It works and is a good process to use in the right circumstances.

Peter Gomena
 
Thanks both! I'll try it on crummy neg 1:2 with water with a bath of hypo clear before and after and a good wash and see what happens. It's a well exposed neg, there's shadow detail but the highlights are grim. Underdeveloped I assume. Apparently it's good for N+1 contrast. I also thought bleaching back the highlights might be an option. However, I only have the bleach supplied with variable sepia toner. Would this work similarly to farmers or are they 2 very different beasts?
 
However, I only have the bleach supplied with variable sepia toner. Would this work similarly to farmers or are they 2 very different beasts?

Offhand I don't know. The issue is proportional versus nonproportional reduction. You want the latter. Farmers can be used for nonproportional reduction if you mix it accordingly (only use one part IIRC)... and that would bring pop to a print by selectively brightening the highlights. Dunno about your sepia bleach, I recall that it goes aggressively for highlights first, but I don't know offhand whether it more or less proportional than the non-proportional Farmer's mix. You want something really nonproportional!

Anyway, you can of course also selectively bleach, with a brush, certain areas of a print. Maybe that kind of "highlight brilliancing" strategy would work for your print, if whatever reducer you use is too proportional.
 
I went ahead and threw myself into intensifying the neg, just tried printing it then and whaddaya know, it works amazingly! Exactly what I was hoping for. That was 1:1 with water for 10 mins, so I accidentally made it too strong! I'm not very good at following instructions! The neg looks purple as you would expect with selenium but doesn't look denser really so wasn't expecting such a pronounced result. It will benefit even more from a very light bleaching and sepia followed by a selenium.
 
I've had good results in the past with selenium toning negs. Selenium works initially on areas where there is the most exposed silver so this means the shadows on a print and the highlights on the neg. I've found it good for negs exposed in flat / grey lighting where the highlights can be a bit muddy. I normally dilute 1:2 or 3 (KRST) and tone until there's a slight magenta cast ( maybe this colour ups the contrast aswell ?)
I've heard it said that the process can also give the neg a small increase in sharpness (something to do with the selenium affecting the grain structure ??) I guess though this could just be perceived sharpess due to the increase in contrast.

You also get archival negs too !
 
Last edited by a moderator:
I tried it on a couple of negs. Used Steve Anchell Darkroom Cookbook (3rd ed) as guide. He has a chapter on intensifiers/reducers. The steps:
1) soak in water for couple of minutes
2) plain Hypo fixer for 5 mins. This step can be skipped if you are sure your original film fixer had no hardener.
3) Selenium at 1:2 parts water for 3-5 mins in white tray under room light so you can see any changes. The tray should be larger than the neg, otherwise you could get surge patterns from agitation. I used Berg Selenium that doesn't have fixer.
4) rinse for 5-6 mins
Measured the results with a densitomer and got 1.5 stops density increase.
 
Last edited by a moderator:
The 1:1 dilution that you used is what John Sexton recommends. Doing this can get you the equivalent to N+1 development, and also helps make the image more permanent.
 
I'm just now getting back into LF after "many" years but when I shot black and white I used selenium as a normal part of my process. I shot Agfapan films (usually 25 ISO but 100 also) overexpose somewhat, under developed in Rodinal (1:50 or 1:100), then selenium toned (dilution ?). This kept the shadow details open and the highlights unblocked. This works because the toner, as you know, adds contrast by affecting negative highlights more than the shadows. The end result was negatives with a longer straight line on the gamma curve than is otherwise possible which translates into increased accutance. I shot at least three negs of each scene and processed and toned one at a time so I could fine tune the procedure for the image. Yes, shooting three sheets cost a lot but I was extremely selective in what I shot so it didn't make much difference. I printed on Gallery #3 and toned the prints also. This adjusted color and had a similar deepening affect of the shadows on the print. BTW, you probably already know that selenium toner can also be a valuable part of archival processing. It's marvelous stuff, IMHO.
 
Last edited by a moderator: