How to achieve midtone bump on B&W film / darkroom print?

radiant · Nov 9, 2020

Is it possible to achieve a "midtone" bumping on B&W film & paper?

I mean this kind of transformation:

.. to => ..

ic-racer · Nov 9, 2020

I don't know what you are showing. What are the axes. If this is a print, then burning multigrade paper with blue light (number 5 in the diagram) will darken the shadows like that.

radiant · Nov 9, 2020

Ahm, sorry. Those are normal levels-dialog values: X is original tone and Y is intensity.

I guess contrast is S-curve as what I'm after is just a single point "bow" ?

Raghu Kuvempunagar · Nov 9, 2020

@vedostuu: Not sure if this is what you're looking for but this interview of printer/photographer Sergio Purtell could be of interest to you:

"I think the style of printing for mid-tones was a little bit of that time. I remember that Richard gave me a piece of material used in offset printing that was the equivalent of a double 00 filter that I would use to flash the print as a final touch to fill in any potential too bright highlight. Also I would split filter my prints. I can tell you that all this was incredibly tedious and time consuming, but in the end it would yield these beautifully open prints, with every possible midtown and a touch of black in the shadow areas and compressed highlights."

radiant · Nov 9, 2020

Raghu Kuvempunagar said:
@vedostuu: Not sure if this is what you're looking for but this interview of printer/photographer Sergio Purtell could be of interest to you:

"I think the style of printing for mid-tones was a little bit of that time. I remember that Richard gave me a piece of material used in offset printing that was the equivalent of a double 00 filter that I would use to flash the print as a final touch to fill in any potential too bright highlight. Also I would split filter my prints. I can tell you that all this was incredibly tedious and time consuming, but in the end it would yield these beautifully open prints, with every possible midtown and a touch of black in the shadow areas and compressed highlights."

I'm looking for boosted mid tones while maintaining black black and white white.

Does Sergio basically describing multigrade printing technique? Or am I missing something?

ic-racer · Nov 9, 2020

vedostuu said:
Ahm, sorry. Those are normal levels-dialog values: X is original tone and Y is intensity.

I guess contrast is S-curve as what I'm after is just a single point "bow" ?

So it is a transparency not a print?

radiant · Nov 9, 2020

No. Well yes transparency to print.

I refine more: how to make print with bumped midtones (see example from picture at first post) from B&W negative?

ic-racer · Nov 9, 2020

So, if that is a transparency, when you write "bump" you want it brighter, or less density. In that case you will probably need two masks to control that. More info here:

Doremus Scudder · Nov 9, 2020

In the analog world, there are a couple of ways to manipulate the curve shape of the final print relative to the original scene in the way that you desire (that is, if I'm understanding your explanation correctly).

The first is direct manipulation of the curve on the negative by using (a) a film with a pronounced shoulder and/or (b) compensating development or (c) SLIMT techniques to achieve a steeper contrast curve (C.I. or contrast index) in the mid-tone area of the negative.

Then, when printing (analog) one can choose a paper with a long toe and/or use flashing or split-printing techniques (e.g., printing contrasty and then burning highlights with a low-contrast filter, etc.) to achieve more mid-tone contrast.

Masking is another (more advanced) technique to manipulate the contrast curve in the final print.

These are thngs analog photographers have been doing for decades (if not a century).

Best,

Doremus

grain elevator · Nov 9, 2020

Printing at a hard grade (for the steep part of the curve) and flashing the paper (to round off the shoulder) might do it?

radiant · Nov 10, 2020

grain elevator said:
Printing at a hard grade (for the steep part of the curve) and flashing the paper (to round off the shoulder) might do it?

Doesn't this lower the contrast?

I wish I had some "simulation" tool to comprehend the effect Maybe I just try it out!

radiant · Nov 10, 2020

Doremus Scudder said:
In the analog world, there are a couple of ways to manipulate the curve shape of the final print relative to the original scene in the way that you desire (that is, if I'm understanding your explanation correctly).

The first is direct manipulation of the curve on the negative by using (a) a film with a pronounced shoulder and/or (b) compensating development or (c) SLIMT techniques to achieve a steeper contrast curve (C.I. or contrast index) in the mid-tone area of the negative.

Then, when printing (analog) one can choose a paper with a long toe and/or use flashing or split-printing techniques (e.g., printing contrasty and then burning highlights with a low-contrast filter, etc.) to achieve more mid-tone contrast.

Masking is another (more advanced) technique to manipulate the contrast curve in the final print.

These are thngs analog photographers have been doing for decades (if not a century).

Best,

Doremus

Can you give examples of films with pronounced shoulder or paper with long toe?

BTW: I didn't know SLIMT so I checked up on it and it is described

"SLIMT, short for Selective Latent Image Manipulation Techniques, is a technique for pre-bleaching of exposed, but undeveloped, prints and negatives in order to control shadow and highlight contrast in a largely beneficial direction without adversely affecting overall micro-contrast. For prints, one generally manipulates shadow contrast and for negatives one generally manipulates highly contrast."

Andrew O'Neill · Nov 10, 2020

An unsharp mask on your negative will give you a bump in the midtones...as well as sharpness and acuteness.

Doremus Scudder · Nov 10, 2020

grain elevator said:
Printing at a hard grade (for the steep part of the curve) and flashing the paper (to round off the shoulder) might do it?

I didn't mention this specifically, preferring the technique of burning highlights at a lower contrast setting, but yes, indeed, this works well too!

vedostuu said:
Doesn't this lower the contrast?
I wish I had some "simulation" tool to comprehend the effect Maybe I just try it out!

It does indeed lower the contrast of the highlights. The idea is to print at a contrast setting/grade that is "too contrasty" for the negative and then use flashing (or burning at a lower contrast setting) to get some detail in the highlights, albeit at a lower contrast gradient than the midtones. The result is contrastier middle values and less-contrasty highlights. Exactly the effect you seem to be after.

vedostuu said:
Can you give examples of films with pronounced shoulder or paper with long toe?

The current crop of tabular-grain films all have pretty straight shoulders well up to close to the top of the curve. Older-style films like the now-defunct BPF-200 had a pronounced shouldering. There are likely several "old-style" films out there that will exhibit similar shoulder curves too. Much of the curve shape depends on the developer. I can't help much with specifics here, preferring negatives with lots of contrast in the highlights too, which I can then subdue at the printing stage if needed.

BTW: I didn't know SLIMT so I checked up on it and it is described.
"SLIMT, short for Selective Latent Image Manipulation Techniques, is a technique for pre-bleaching of exposed, but undeveloped, prints and negatives in order to control shadow and highlight contrast in a largely beneficial direction without adversely affecting overall micro-contrast. For prints, one generally manipulates shadow contrast and for negatives one generally manipulates highly contrast."

SLIMT for negatives (not prints) and compensating development techniques both have a similar result, albeit using different mechanisms: to reduce contrast in the highlight portion of the negative. This changes the characteristic contrast curve of the negative to one similar to the one in your "midtone bump" histogram above; i.e., steeper in the middle and then tapering off with the highlights. FWIW, I use SLIMT techniques for extreme contractions since effective film-speed loss is less than with reduced development and the midtones retain much of their "normal" contrast.

Best,

Doremus

Bill Burk · Nov 10, 2020

HC-110 and Tri-X

Bill Burk · Nov 11, 2020

The bump I have seen on some curves with HC-110 is so slight I don’t think it can be put to pictorial use.

Craig75 · Nov 11, 2020

Is it not just a case of printing shadows and mids at one contrast and highlights at a softer contrast.

radiant · Nov 11, 2020

Craig75 said:
Is it not just a case of printing shadows and mids at one contrast and highlights at a softer contrast.

I think you are saying here "print with higher contrast" which is same as S-curve. Or how do you limit certain contrast to shadows/mid tones only?

bernard_L · Nov 11, 2020

vedostuu said:
Can you give examples of films with pronounced shoulder or paper with long toe?

Neopan 400 in D-76 1+1. A hint of a shoulder in the mid-tone region ; just right IMO to deliver slightly "airy" mids. Nice film if you can get some.
APX-100 (old, true one) in Rodinal. More pronounced shoulder; too strong effect IMO for the average outdoors scene, kills the contrast of light tones; great for, e.g. indoors scene where you want to also show the outdoors through a window without increasing too much the range of densities on the negative.

Craig75 · Nov 11, 2020

vedostuu said:
I think you are saying here "print with higher contrast" which is same as S-curve. Or how do you limit certain contrast to shadows/mid tones only?

If you turn the contrast up and/or develop longer you can separate and burn in the highlights separately on a softer grade. It might need some good skills though to burn in complicated highlights.

Dave Krueger · Nov 11, 2020

vedostuu said:
Is it possible to achieve a "midtone" bumping on B&W film & paper?

I mean this kind of transformation:

View attachment 258953

.. to => ..

View attachment 258954

I think ic-racer hit the nail on the head in post #8. Basically, masks are made to manipulate analog tone curves. You can find some example of what contrast masks can do here: https://www.maskingkits.com/maskingexamples.htm

It's not as easy as pulling a tone curve up with a mouse click, but it can be fun and, from what I've heard, it becomes easier the more you do it. I have the Radeka masking kit and have done it, but I don't shoot enough large or medium format film to become adept at it. It's not something that works very well with small negatives because of the precision required.

How to achieve midtone bump on B&W film / darkroom print?

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