SLIMT - Minus Development

I just did an APUG Title search for SLIMT (Selective Latent Image Manipulation Technique) and was amazed that there was no thread about this method to give minus development to negatives.

In a nut shell, you can keep your shadow contrast and bring the high tones under control...and get ready for this...while you develop your minus negatives with your normal negatives. Really!

For David Kachel's original article go here:

(there was a url link here which no longer exists)

Murray

Does anybody else use SLIMT? I use a slight variation (10 cc instead of 8 cc) on the method given in Lynn Radeka's Masking Kit.

Murray

I've used it on a few negatives, and have had good success with it. I concurr with what you say above about increasing the strength of the dilution to obtain a true N- reduction in contrast. The dilutions mentioned by Lynn do seem a bit weak to obtain the stated reductions. I wonder what type of enlarger he's using, and if that has any impact on the required dilutions?

I use hangers and tanks to develop my 4x5 negs, so while the ability to develop all my negs together isn't that important (you can always pull some early to do N-1), it makes developing film easier since you don't have to keep track of which negs to pull early.

The only thing that concerned me was the pre-soak that the negatives would get before hitting the developer. I had never done a pre-soak before, so I was unsure of what the effect would be on my developing times. So far, I have not made any adjustments...

I use it for both film and papers. It is just as applicable to usage for printing color negatives.

For those that want to try SLIMT, here is how: (there was a url link here which no longer exists)

Murray

MurrayMinchin said:

Does anybody else use SLIMT?

Click to expand...

I intend to work with SLIMT. I shoot 120 with a mix of SBR on
each roll. My interest is using it for contrast control when printing.
It is my understanding that contrast reduction is it's only use. Is
that true?

I've been working with Beer's contrast control developer but
wonder if I've just been spinning my wheels. The SLIMT method
looks to be so fool proof, so quick, so easy.

Also, why use the method when developing film when control is
so possible when printing?

I've opted for Graded Paper and the very well lit, not dark
darkroom they allow. Whole print contrast control methods are
an ongoing interest. Dan

Hi Dan,

It sounds like you're asking about the Sterry Method of controlling print contrast? SLIMT is for negatives. Since I use sheet instead of roll film, why not expose and develop each negative to suite each subject? I chose the variable contrast / masking route to control print contrast, so I don't know how to answer your question.

David Kachel wrote an article entitled, "Variable Contrast from Graded Papers" where he describes his method using potassium ferricyanide, instead of Sterry's potassium dichromate: Dead Link Removed There should be quite a few things to Google up on how to do the Sterry Method.

Sorry I can't be more help, but at least it gives you two paths to start down.

Murray

dancqu said:

I intend to work with SLIMT. I shoot 120 with a mix of SBR on
each roll. My interest is using it for contrast control when printing.
It is my understanding that contrast reduction is it's only use. Is
that true?

I've been working with Beer's contrast control developer but
wonder if I've just been spinning my wheels. The SLIMT method
looks to be so fool proof, so quick, so easy.

Also, why use the method when developing film when control is
so possible when printing?

I've opted for Graded Paper and the very well lit, not dark
darkroom they allow. Whole print contrast control methods are
an ongoing interest. Dan

Click to expand...

The bleaching of the latent image acts more or less in proportion to the amount of silver, so on negatives it reduces highlight density more than shadow, and the opposite for positives. So, yes, it reduces contrast. Intensifying the latent image would raise the contrast provided the intensified image is silver or another metal that acts as a catalyst for development as silver does.

I have tried the SLIMT for printing as described by Kachel, and while it works, I could not see the difference from a flashing technique I call "while flashing" in which I set the amount of flashing illumination with the enlarger on. I have an easel densitometer by which I can set the brightest area to print black and adjust the flashing illumination to make the highlights, say Zone VIII, to be just barely darker than white. There is this difference: with SLIMT I lose the ability to set exposure with my meter.

gainer said:

The bleaching of the latent image acts more or less in proportion to the amount of silver, so on negatives it reduces highlight density more than shadow, and the opposite for positives.

Click to expand...

That's a good point...same effect, opposite results.

We are going to get WAY confused though if we don't seperate the two processes by name...isn't it SLIMT for negatives and the Sterry Method (or Kachel's New Sterry Method) for prints? I know Kachel lists papers near the end of his SLIMT article, but then he calls it the New Sterry Method in the paper article.

Murray

MurrayMinchin said:

That's a good point...same effect, opposite results.

We are going to get WAY confused though if we don't seperate the two processes by name...isn't it SLIMT for negatives and the Sterry Method (or Kachel's New Sterry Method) for prints? I know Kachel lists papers near the end of his SLIMT article, but then he calls it the New Sterry Method in the paper article.

Murray

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I read Kachel's article years ago in "Darkroom and Creative Camera Techniques" and it was IIRC a very detailed description of the use of extremely dilute ferricyanide solution to reduce the contrast of the latent image in printing papers. I don't recall seeing the name "Sterry" in that article. He did mention the use of other bleaches, and the possibility of using the general method on film, but I have lost the issue and cannot refresh my memory of it.

Whatever we call it, the idea is the proportional bleaching of the latent image. Potassium dichromate is used in intensifying processes, and so could possibly intensify the latent image. I would think that a silver intensifier might work as well, but the problem in printing is not as often to increase contrast as it is to decrease it. An underdeveloped negative can more easily be intensified or printed satisfactorilly on a higher grade of paper than an overdeveloped negative can (safely) be reduced or (satisfactorilly) be printed on softer paper.

With regard to paper, both flashing and bleaching the latent image can retain contrast in the shadows while reducing contrast in the highlights. It is much like the compensating effect sought by many in development of negatives.

The opinions expressed herein are those of their author, of course.

As someone who has used the Sterry process in the past it is ocassionally a useful process.

However you posting this is more about publicity for David Katchel's article, after all you start by saying that after doing a search on this forum there is no trace, then you link to a post here, which just happens to be one of your own posts, so self publicity.

After all you say "was amazed that there was no thread about this method to give minus development to negatives." So strange you can remember what you posted a few days earlier, and even post the link.

I did read the article, and I already knew how the process works but there are no photographs illustrating the effects, which I find qite strange. Some examples would be useful as I'm sure that this process needs a lot more evaluation.

Ian

MurrayMinchin said:

I just did an APUG Title search for SLIMT (Selective Latent Image Manipulation Technique) and was amazed that there was no thread about this method to give minus development to negatives.

In a nut shell, you can keep your shadow contrast and bring the high tones under control...and get ready for this...while you develop your minus negatives with your normal negatives. Really!

For David Kachel's original article go here:

(there was a url link here which no longer exists)

Murray

Click to expand...

Hey Ian...Whoa There Big Fella!

I'm a hack...a nobody...a photographer who was isolated by geography in his own little world until I was given a hand-me-down computer - hence no photographs because there is no scanner, and even the printer doesn't work.

Sorry I'm not up to proper posting etiquette where my amazement of not finding SLIMT on a title search cannot extend past the first post where I mentioned it. I'll try to behave better, as soon as I figure out what the rules are.

Really Ian, what you read is what I am...somebody who has found something that works really well reducing contrast in negatives, and wants others to know about it. I guess I was caught up in the spirit of APUG and wanted to share my good fortune with others. OOPSYDAISY!

I put the link to Kachel's articles because it is the right thing to do. He had the revelation, and went through tons of experimentation and testing to get it right - it would be wrong of me to take the credit as if it was mine. He also has other articles there that would be very interesting to others on APUG as it is all about good old film, paper, and chemicals. (Oh CRAP!!! There I went and did it again!!!!)

Good to see you're keeping your MS/Pederzolli/Ornello radar up...just don't launch any more missles my way please...I'd hate to go down in flames from friendly fire...

Murray

I've used the SLMT method for prints several times. I wrote an article about it 4 or 5 years ago entitled Latent Image Bleaching. It is at http://unblinkingeye.com/Articles/LatentImageBleach/latentimagebleach.html. All my information came from David Kachel's articles, which are now available on his website.

MurrayMinchin said:

Does anybody else use SLIMT? I use a slight variation (10 cc instead of 8 cc) on the method given in Lynn Radeka's Masking Kit.

Murray

Click to expand...

I finally got around to trying SLIMT yesterday on some test negs. I had found that with Delta or other T-grain films, I wasn't getting the results from N-minus development that I wanted.

So I set up a test scene with a more-than-seven zone range of luminance values and exposed four negs identically. I then began SLIMT testing according to Kachel's recommendations.

The effect was very promising. I still have some fine tuning to do to make it utterly predictable, and I think that I will have to increase exposure by about one stop for negs that I intend to do this with. But so far, my rough results are that 20ml working stock solution (see Kachel's article) of Ferricyanide per liter of water at 4 minutes at 72F gives me slightly more than a one-stop reduction with Delta 400 exposed at 200.

Larry