methods for more contrast???

RalphLambrecht said:

Mark

Development has an effect on film speed. Exposure compensation is therefore required for a contrast change if you want two negatives with similar shadow detail. If you don't have that, you cannot reliably measure the difference in contrast between the two negatives.

A change in development always goes along with a change in exposure.

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True, but the change in shadow placement is minimal to insignificant, a choice to use +1 development may mean that the real film speed changes from 400 to 500. Human metering errors are a bigger problem.

Ditto what Mark and Ralph said. Giving film a +1 development will increase film speed by about 1/3 stop. If you're obsessive about the zone or beyond-the-zone systems, and you have tailored your film exposure/development to exacting paper tonal reproduction scales, you make an allowance for this. If you goof and forget it, no real harm is done.

As to the "logical fallacy" in Thomas' post, I think what Thomas is saying is that two films of differing inherent contrast can be manipulated to produce similar negative contrast by altering developer concentration and/or development time.

If you are testing and comparing your materials, you would start by using the same developer concentration for both films. That is the true test of the materials and process. This would show the inherent differences between the films. The FP4+ would be contrastier than the Tri-X. Subsequent testing would allow you to manipulate the FP4+ curve to more closely match the Tri-X. My hunch would be that the FP4+ would lose some of its speed and mid-tone punch in the process. (Reduced agitation schemes aside.)

You just have to try it and see how it works. Set up a logical test situation with minimal variables and see what happens. The Beyond the Zone System manual or Fred Picker's Zone VI Workshop are good starting references. If you just go about changing exposure and development, you'll chase your tail for months and waste a bunch of film and paper (that's money) in the process.

Peter Gomena

markbarendt said:

True, but the change in shadow placement is minimal to insignificant, a choice to use +1 development may mean that the real film speed changes from 400 to 500. Human metering errors are a bigger problem.

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Who said, we're limited to N+1 development? I test my films from N-2 to N+2 and see more than a stop difference in exposure between these two values. That's hardly insignificant and hopefully beyond anybody's measurement error.

I think it's important to understand that a change in development always goes along with an appreciable change in exposure.

So Ralph, across a 5-stop change in film contrast (development) you are seeing a bit more than a one stop change in film speed, is that right?

That's roughly the same 1/3 stop change in film speed per stop of contrast (development) change that has been alluded to here, it's a maximum error of 2/3's of a stop up or down with regard to the camera exposure setting.

You are correct in that it is good to adjust exposure to match the process plan, one of my points is that just because the SBR indicates +2 development doesn't mean that we should shoot 2 stops underexposed, 1/3 to 2/3 maybe but not 2.

pgomena said:

Ditto what Mark and Ralph said. Giving film a +1 development will increase film speed by about 1/3 stop. If you're obsessive about the zone or beyond-the-zone systems, and you have tailored your film exposure/development to exacting paper tonal reproduction scales, you make an allowance for this. If you goof and forget it, no real harm is done.

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But returning to the point: underexposure with overprocessing is a way to increase contrast.

pgomena said:

As to the "logical fallacy" in Thomas' post, I think what Thomas is saying is that two films of differing inherent contrast can be manipulated to produce similar negative contrast by altering developer concentration and/or development time.

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So far, so good.
But if, like Thomas, you offer this as proof that different films don't have different contrasts...
The way you worded the thing ("two films of differing inherent contrast") makes it easier to see the fallacy in his conclusion, that "it's incorrect to say that one film has more contrast than another".

Q.G. said:

But returning to the point: underexposure with overprocessing is a way to increase contrast.

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Why the insistence on underexposure?

And

How much are you suggesting?

Q.G. - I agree that different films have different inherent contrast. Faster films have a longer tonal range and tend to be less contrasty than slower films. Can slower films be manipulated to mimic the tonal range of faster films? Yes, to some extent. Can you get a lot of contrast out of a fast film? Yes. I've ruined enough film to know. Do I use PanF+ in contrasty light? No. Do I want to try to expand HP5+ to N+2 in very flat lighting? Probably not.

There are a lot of variables at play here. If the OP wants more contrast, increasing development or using a selenium intensification bath to already processed negatives will be a starting place. "Underexposing and overdeveloping" introduces two variables at once and may cause more headaches than it is worth. He needs learn to test his materials properly or he'll run in circles.

Peter Gomena

I remember watching this video clip of Bruce Barnbaum a long time ago, he talked about this sort of thing. It gets more specifically about the things discussed here at 6:20, but the whole thing is great.

http://www.youtube.com/watch?v=rlnt5yFArWo

markbarendt said:

Why the insistence on underexposure?

And

How much are you suggesting?

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So the highlight details may be kept.

Everything is a trade-off though. Some people might not mind losing highlight detail, some might not mind losing shadow detail. You may retain all detail, but that's why you may want to underexpose.

markbarendt said:

So Ralph, across a 5-stop change in film contrast (development) you are seeing a bit more than a one stop change in film speed, is that right? ...

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Correct!

markbarendt said:

... That's roughly the same 1/3 stop change in film speed per stop of contrast (development) change that has been alluded to here...

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Correct!

markbarendt said:

... You are correct in that it is good to adjust exposure to match the process plan ...

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markbarendt said:

... one of my points is that just because the SBR indicates +2 development doesn't mean that we should shoot 2 stops underexposed, 1/3 to 2/3 maybe but not 2.

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That's correct too, but who said one should underexpose by 2 stops for an N+2 development?

markbarendt said:

Why the insistence on underexposure? ...

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So shadow and highlight densities end up as intended.

markbarendt said:

... How much are you suggesting?

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Attached are two examples: (see the lower right-hand graph)

markbarendt said:

Why the insistence on underexposure?

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Because underexposing alone will already increase contrast, letting the lower end of the scale drop off it. There is no bigger contrast than that between something that is on the negative and that which isn't even there.
And what Ralph says. I don't beieve i could improve on what he says, so i leave you with that.

Why do you keep asking about underexposure, as if it has nothing to do with contrast control?

Another way to increase contrast is to make long exposures -- using the reciprocity failure of the film to cause the exposure rate in the shadows to lag behind the exposure rate of the mid tones and highlights (basically underexposing just the shadows) and then developing for the normal time or giving the film extra development.

Feel free to ignore this part:
Just to make things interesting, the terms "under exposing" and "over exposing" are a bit mis-leading as they are often used to designate mistakes made in exposing -- rather than purposefully placing values where one wants them. So in the above situation I am not using the reciprocity failure of FP4+ to underexpose the shadows, but am placing them in a lower zone than a reciprocal short exposure would normally place them.

Now we are talking a common language.

RalphLambrecht said:

That's correct too, but who said one should underexpose by 2 stops for an N+2 development?

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Kodak, Ilford, Fuji... The product manufacturer's directions all indicate this 1:1 ratio and the general public has come to expect this 1:1 ratio not a 1/3:1 ratio.

Here we are, relatively knowledgeable people, arguing about the point at which we need to start adjusting exposure for + or - changes in process, because we have different styles and personal tolerances.

For me, most of the time 1/3, even 2/3 of a stop isn't enough to worry about.

On my RB 1/2 stops are the norm, on my 4x5 where aperture is on an infinite but marginally accurate scale it's a guess anyway, the Petzval lens I use a pair of darkslides as a shutter on is even worse. My cameras like many others, simply don't have the ability to be truly precise. My Holga is essentially a fixed exposure machine, my FM2 can adjust on the fly to 1/3 precision on film speed but the shutter is 1 or none. It's only when I reach for my N90s's that 1/3 becomes truly workable and reliable but my 35mm camera films normally have various changes to subject matter and scene contrast scattered across most rolls.

I'm not abnormal here, these are problems most of us face.

All of these cameras pose problems in precision for the process, silly things anyway.

Even with all these precision issues I do decide here and there to add or reduce exposure and/or play with the contrast target in development for effect.

Given the precision my tools are capable of, adjustment is more art than science. 2/3's of a stop one way or another at the shutter is about as close as I can get and one of big the reasons why I prefer negatives over trannies.

My machines demand latitude and I don't mind giving it.

Vaughn said:

Feel free to ignore this part:
Just to make things interesting, the terms "under exposing" and "over exposing" are a bit mis-leading as they are often used to designate mistakes made in exposing -- rather than purposefully placing values where one wants them.

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I agree!

The original post did not state how much of an increase in contrast is desired. If a moderate incrase is desired then try Dektol (D-72)diluted 1+9 to 1+19. Many people don't know that D-72 was formulated by Kodak as a universal developer for both papers and films. D-72 is convenient and readily available.

markbarendt said:

... Kodak, Ilford, Fuji... The product manufacturer's directions all indicate this 1:1 ratio and the general public has come to expect this 1:1 ratio not a 1/3:1 ratio. ...

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Where do you get this? I have never heard or seen this and I haven't seen it mentioned in this thread either.

markbarendt said:

Why the insistence on underexposure?

And

How much are you suggesting?

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Don't think of it as under exposure, rather less or more exposure to anchor shadow values and manipulate highlight values so film D has an impact on effecting desired film and resulting print contrast

Gerald C Koch said:

The original post did not state how much of an increase in contrast is desired. If a moderate incrase is desired then try Dektol (D-72)diluted 1+9 to 1+19. Many people don't know that D-72 was formulated by Kodak as a universal developer for both papers and films. D-72 is convenient and readily available.

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D72 was formulated as a Negative developer, only later was it recommended for papers as well. In the 1949 UK "Kodak Chemicals & Formulae" it's only recommended as a rapid negative developer. likewise in the Kodak Research, Harrow (1944), Formulary.

Kodak (UK) recommended D163 rather than 72. seems to have been a difference in approach by Kodak UK and Eastman Kodak.

However the principle of using a developer like this dilute works well, Ilford recommend PQ Universal for slightly higher contrast with their Ortho Plus film but it works equally as well with FP4 and other Ilford films. At least one APUG member uses it for his Platinum/Palladium negatives. Use 1+29 the grain is surprisingly fine.

Ian

RalphLambrecht said:

Where do you get this? I have never heard or seen this and I haven't seen it mentioned in this thread either.

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Yes the 1:1 thing is misinformation. It was still the impression I got when I was learning from the processing charts and indirectly reinforced from info given here on APUG and other sources.

I had to unlearn this.

I think it's normal for newbies to get into pushing before they get into contrast control or shadow placement. The imperative is getting "something workable" not necessarily "something great". Pushing is taught 1:1; If you change exposure by 1-stop you go to the chart and change development by 1-stop. This becomes the baseline experience.

Later on "we" learn that the film speed doesn't really change that much.

When we get further along on our learning curve

Ian Grant said:

...At least one APUG member uses it for his Platinum/Palladium negatives. Use 1+29 the grain is surprisingly fine.

Ian

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I use PQ Universal with FP4+ from 1+29 to 1+9 for pl/pd and for carbon printing negs -- but fortunately grain is not an issue with contact printing. I can't get it to do much (relatively speaking) with HP5+.

Vaughn said:

I use PQ Universal with FP4+ from 1+29 to 1+9 for pl/pd and for carbon printing negs -- but fortunately grain is not an issue with contact printing. I can't get it to do much (relatively speaking) with HP5+.

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You were the at least one

I tested PQ Universal at 1+29 with 35mm FP4 in the mid 1980's and found it gave very similar results to HC110 in terms of fine grain, sharpness & film speed. May & Baker sold their equivalent Suprol to Photofinshers where it was used for both film & print processing.

We used PQ Univeral for 5x4 copy negatives with Ilford commercial Ortho (same as Ortho Plus) or FP4 and it always gave excellent results at 1+19.

Ian

There will be subtle differences between printing on high contrast paper and increasing contrast by increasing negative development time. Try both and see which works best for you.

Ian Grant said:

You were the at least one

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Watch it there -- at 6'4", 240 pounds, no one has ever called me the "least one".

markbarendt said:

... I had to unlearn this. ...

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Apparently, it hasn't left you entirely. Why bring it back into this thread then?