Theory of Contrast, Pulling and Pushing in Black and White Development

[JPSuisse]

Hi all

After my first trials developing film, I’m still really wondering about contrast. I’m trying to make negatives that are a little more “contrasty.” Many people here do like flat negatives for various reasons. I scan my negatives, but I hate post-processing. I find it easier to just scan a relatively “contrasty” negative and do less post-processing. Of course, I’ve got a Nikon 5000 that can handle “contrasty” negatives pretty well. The flat negatives I got from the labs were just not good enough.

I’m thinking now that:

1.) Shooting at a lower EI than the box ISO, i.e. pulling, means logically less development times, which means lower contrast generally.

2.) Shooting at a higher EI that the box ISO, i.e. pushing, means logically more development times, which means higher contrast generally.

Given this situation, theoretically speaking, should I even be shooting at a lower EI than box speed? Or, can I just increase the development time to get back the contrast that I am losing by developing a little less. And anyway, all these recommendations I hear about shooting at a lower EI than box, what good are they?

Well, any thoughts on this would be appreciated.

JP

 

[Roger Hicks]

Development is overwhelmingly the main controller of contrast.

Increase development -- at any EI -- and you'll get more contrast.

Most people who shoot at lower than box speed are doing so to compensate for the fact that they are not metering appropriately, i.e. using a true spot meter and metering the darkest area in which they want detail.

See http://www.rogerandfrances.com/subscription/ps neg development 1.html for more information.

Cheers,

R.

 

[titrisol]

What Roger said, increase your dev time by 10% at a time until you get what you want.

 

[Vince Lupo]

I'm not totally up on scanning contrasty negs, but I know that printing contrasty negs in a darkroom can be a bit of trouble. The old adage 'expose for the shadows, develop for the highlights' is one reason why people expose their film at 1/2 the rated ISO. By doing that, you bring in that extra shadow detail that you wouldn't otherwise get by exposing at the rated ISO, and you'd then cut the development by as much as 1/3 to keep your highlight detail in check (of course, this varies from personal 'system' to personal 'system' - camera, meter, film, developer, etc). Additionally, it also depends on whether you will be using a condenser or diffusion enlarger (you'd want more contrast for diffusion enlargers, less for condenser). For printing, I personally like flatter negs -- it is much easier to add contrast to a flat neg than it is to try and remove contrast from a contrasty neg. Here again, I can't really speak to how this all computes for a scanner, but I would imagine that a scanner can't scan what isn't there (i.e. shadow or highlight detail that's all blocked up or not there).

 

[Calzone]

I'm not totally up on scanning contrasty negs, but I know that printing contrasty negs in a darkroom can be a bit of trouble. The old adage 'expose for the shadows, develop for the highlights' is one reason why people expose their film at 1/2 the rated ISO. By doing that, you bring in that extra shadow detail that you wouldn't otherwise get by exposing at the rated ISO, and you'd then cut the development by as much as 1/3 to keep your highlight detail in check (of course, this varies from personal 'system' to personal 'system' - camera, meter, film, developer, etc). Additionally, it also depends on whether you will be using a condenser or diffusion enlarger (you'd want more contrast for diffusion enlargers, less for condenser). For printing, I personally like flatter negs -- it is much easier to add contrast to a flat neg than it is to try and remove contrast from a contrasty neg. Here again, I can't really speak to how this all computes for a scanner, but I would imagine that a scanner can't scan what isn't there (i.e. shadow or highlight detail that's all blocked up or not there).

Vince, thanks for your post, as it provides a foundation and an opportunity to expand upon.

I assume the variable contrast enlargers I use are diffusion enlargers that benefit from more contrast as stated above. Being a lazy slacker, and also because a college professor in art school taught me to produce consistent negatives that straight print on number two graded paper without variable contrast filters, I sought out higher contrast negatives via exposure and developement.

My solution was to shoot HP5 at ASA 650, a little more than half a stop, and develope with Ilford Microphen using three to one dillution for fine grain via extended developement time. In a round about way, I was learning about Ansel Adam's ideas and concepts about exposure and negatives. This zone system is very interactive and produces great variation, and all this learning was sticking with one film HP5.

I became very consistant in both my exposures and negatives. BTW a meter reading from the back of my hand is the same off a grey card. If you are racially fair skinned a meter reading is likely to be off (overexposed) by two stops.

I also would recommend that pulling film one stop is great for making negatives "more creamy," and this can be usefull for taking portraits, when shooting under harsh lighting, or shooting under extreame contrast like at night. For HP5 shot at ASA 400 or 200 I recommend Ilford ID-11 or D-76. Use one-to-one dilution if you like finer grain and slightly less contrast.

Less is more in a creative way. HP5 can provide three film speeds and a lot of contrast control with only two developers. I assume similar results could be obtained with Tri-X. My world is rather limited to mostly HP5, but I love the results.

Calzone

 

[Roger Hicks]

A very thorough explanation of this can be had by studying the Zone System as explained in the book, The Negative, by Ansel Adams.

It is the second of three books by Adams, the first is The Camera and the third is The Print. Taken as a whole they comprise a pretty good self paced course in photography.

If you can stand them. I find them needlessly complicated and jargon-ridden. The Zone System is, after all, a subset of sensitometry, over-simplified in some areas and over-complicated in others.

When I first came to them, I didn't understand them, and I was unimpressed. When, some years later, I could understand them, I didn't need them, so I was still unimpressed. In the meantime I had read many books I found easier to understand, and more comprehensive.

I know this is heresy and that many love them. On the other hand, it's worth pointing out to others that they are not for everyone, and there is no need to feel inadequate if you can't bring yourself to join in the adulation.

@Calzone: incidentally, HP5 in Microphen has a true ISO of about 650, so 400 would be a pull (or overexposure). Source: Ilford.

Cheers,

R.

 

[Vince Lupo]

A more easily digestible Zone System book might be 'The New Zone System Manual' by Minor White, Richard Zakia and Peter Lorenz.

 

[Roger Hicks]

A more easily digestible Zone System book might be 'The New Zone System Manual' by Minor White, Richard Zakia and Peter Lorenz.

Hate to appear grumpy, but I though that was even worse, though not as bad as Salzer's A Zone System for All Formats (I've read or tried to read most of 'em). Haist; Glafkides; Coote; Neblette; Dunne and Wakefield; Clerc; I'd back any of 'em against anything on the Zone System.

I'm told that 'Beyond The Zone System' is a lot better but I've never felt the need to buy a copy.

Cheers,

R.

 

[Calzone]

Roger,

Thanks for pointing out HP5's true rated film speed and clarifying that higher film speed is where the extra contrast comes from, but some of Ilford's technical literature causes some confusion as they state ambiguously both 400 and 650 as the film speed.

An example is in a data book that lists developement times, using differant developers. There are no times for ASA 650, but times of 200, 400, 800, 1600, and 3200 are given instead of multiples of 650. This is also true for the instructions that are for their own developers also.

Back in the late seventies, the spec sheet clearly recommended 650 as the film speed. I happened to learn photography in the late 70's and I was fortunate to learn a lot about this great film that has a lot of exposure lattitude.

Any idea why all this confusion exists?

Calzone

 

[Roger Hicks]

Roger,

Thanks for pointing out HP5's true rated film speed and clarifying that higher film speed is where the extra contrast comes from, but some of Ilford's technical literature causes some confusion as they state ambiguously both 400 and 650 as the film speed.

An example is in a data book that lists developement times, using differant developers. There are no times for ASA 650, but times of 200, 400, 800, 1600, and 3200 are given instead of multiples of 650. This is also true for the instructions that are for their own developers also.

Back in the late seventies, the spec sheet clearly recommended 650 as the film speed. I happened to learn photography in the late 70's and I was fortunate to learn a lot about this great film that has a lot of exposure lattitude.

Any idea why all this confusion exists?

Calzone

No, the higher speed doesn't come from more contrast. Under true ISO conditions (constant speed point and contrast), HP5 Plus is 400-ish in D76/ID-11, 650-ish in Microphen and D-76 and 250-ish in Perceptol.

Cheers,

R.

 

[Vince Lupo]

Hate to appear grumpy, but I though that was even worse, though not as bad as Salzer's A Zone System for All Formats (I've read or tried to read most of 'em). Haist; Glafkides; Coote; Neblette; Dunne and Wakefield; Clerc; I'd back any of 'em against anything on the Zone System.

I'm told that 'Beyond The Zone System' is a lot better but I've never felt the need to buy a copy.

Cheers,

R.

No you're not being grumpy - I just thought this one was more of like a 'Reader's Digest' version of the Zone System. Plus, these three guys certainly have a ton of experience, and I found it to be a fairly helpful resource in grad school. I don't think you necessarily need to follow their guidelines to the letter, but they do present ideas that help you understand the effects of 'previsualization', film exposure and development.

 

[Calzone]

No, the higher speed doesn't come from more contrast. Under true ISO conditions (constant speed point and contrast), HP5 Plus is 400-ish in D76/ID-11, 650-ish in Microphen and D-76 and 250-ish in Perceptol.

Cheers,

R.

Roger,

What I was trying to say was higher contrast came from the increased film speed.

Thanks for the info on Perceptol. I need to try it out.

Calzone

 

[charjohncarter]

For me the most important thing is to have all the information that I want and need on the negative. So I shoot below the box speed because I'm mostly not that competent at metering. And then I increase development time so I get close to midtones and highlights that I want. I have a few preset curves in Gimp2 to further tweak my results because I use roll film, so each roll has many lighting situations. By doing this I get all the shadows I need, my midtones are develop to, and I control my agitation for the highlights.

 

[Rob-F]

Hi all
" I’m trying to make negatives that are a little more “contrasty.” Many people here do like flat negatives for various reasons. I scan my negatives, but I hate post-processing. I find it easier to just scan a relatively “contrasty” negative and do less post-processing.

"Given this situation, theoretically speaking, should I even be shooting at a lower EI than box speed? Or, can I just increase the development time to get back the contrast that I am losing by developing a little less. And anyway, all these recommendations I hear about shooting at a lower EI than box, what good are they?

Well, any thoughts on this would be appreciated."

JP

No I don't feel you should be shooting lower than the box speed. You probably should start with the box speed, and then try shooting higher than that, with correspondingly longer development for the reason you have correctly stated: it should give you the contrast you are looking for.

For your purposes, the recommendation to shoot lower than box speed is no good at all. That will get you the opposite of what you want.

I would take it a small step at a time, perhaps in 10% steps as suggested above, because too much contrast will block up your highlights, making the scanning results less satisfactory.

 

[Freakscene]

A few comments. Don't compare apples with oranges. Negatives for scanning are not negatives for wet printing. You can make negatives that work well for both, but the ones that are very best for one won't be so suited to the other.

Sensitometry is technical. I found all of Adams' books overly difficult to understand just because he never wrote very clearly. Remember that he was a very good photographer before the 'zone system' had even been given a name. There's no substitute for understanding your materials.

As for exposing a stop more, Carl Weese, here: http://theonlinephotographer.typepad.com/the_online_photographer/2009/05/do-not-fear-the-sun.html
said:
Now for a digression: for as long as I’ve been using black and white films (since the early 1960s) experienced workers knew that to get the best tonality you needed to expose more (at least a stop more) and develop a bit less, than the manufacturer’s recommendation. In effect, the established standardized rating (known first as ASA and then ISO) was really about a one stop push. So Tri-X at its official speed of 400 wasn’t as bad tonally as Tri-X pushed to 800 or 1600, but it wasn't as good as when rated at 200 or 100. At the official rating, shadow values are weak and difficult to print even just two stops under Middle, and as film is pushed/underexposed this keeps getting worse while extended development makes negative highlights denser without necessarily improving their detail. (Thus comes the dictum of David Vestal about how to handle B&W film, "don’t underexpose, don’t overdevelop.") Careful densitometric testing of film speed to the Zone System standard of Zone I at 0.10 above film base plus fog (fb+f) also generally results in a tested speed one or one-and-a-half stops below the manufacturer’s rating. With proper handling, B&W film retains rich detail two stops or a little more below Middle and three, four, or even five stops above (with some darkroom work to retain those highlights.)

That explains the advantages well. if you need more detail read Ctein's Post Exposure, Advanced Techniques for the Photographic Printer, Silverman, Zuckerman and Shell, pg. 74, The Hand Held Exposure Meter Book.

In terms of the zone system, Beyond the Zone System is by far the clearest book I have read. But in small format it's all somewhat irrelevant anyway, since you can't give individual frames on the same roll different development. You can, of course, always carry different cameras for different light.

For 35 mm film in the kind of photography that most people do, you need no more than not much of a system: http://theonlinephotographer.typepad.com/the_online_photographer/a_simple_system.html

Take pictures and think about what you're doing and what you get too. That helps.

Marty

 

[charjohncarter]

A few comments. Don't compare apples with oranges. Negatives for scanning are not negatives for wet printing. You can make negatives that work well for both, but the ones that are very best for one won't be so suited to the other.

Sensitometry is technical. I found all of Adams' books overly difficult to understand just because he never wrote very clearly. Remember that he was a very good photographer before the 'zone system' had even been given a name. There's no substitute for understanding your materials.

As for exposing a stop more, Carl Weese, here: http://theonlinephotographer.typepad.com/the_online_photographer/2009/05/do-not-fear-the-sun.html
said:
Now for a digression: for as long as I’ve been using black and white films (since the early 1960s) experienced workers knew that to get the best tonality you needed to expose more (at least a stop more) and develop a bit less, than the manufacturer’s recommendation. In effect, the established standardized rating (known first as ASA and then ISO) was really about a one stop push. So Tri-X at its official speed of 400 wasn’t as bad tonally as Tri-X pushed to 800 or 1600, but it wasn't as good as when rated at 200 or 100. At the official rating, shadow values are weak and difficult to print even just two stops under Middle, and as film is pushed/underexposed this keeps getting worse while extended development makes negative highlights denser without necessarily improving their detail. (Thus comes the dictum of David Vestal about how to handle B&W film, "don’t underexpose, don’t overdevelop.") Careful densitometric testing of film speed to the Zone System standard of Zone I at 0.10 above film base plus fog (fb+f) also generally results in a tested speed one or one-and-a-half stops below the manufacturer’s rating. With proper handling, B&W film retains rich detail two stops or a little more below Middle and three, four, or even five stops above (with some darkroom work to retain those highlights.)

That explains the advantages well. if you need more detail read Ctein's Post Exposure, Advanced Techniques for the Photographic Printer, Silverman, Zuckerman and Shell, pg. 74, The Hand Held Exposure Meter Book.

In terms of the zone system, Beyond the Zone System is by far the clearest book I have read. But in small format it's all somewhat irrelevant anyway, since you can't give individual frames on the same roll different development. You can, of course, always carry different cameras for different light.

For 35 mm film in the kind of photography that most people do, you need no more than not much of a system: http://theonlinephotographer.typepad.com/the_online_photographer/a_simple_system.html

Take pictures and think about what you're doing and what you get too. That helps.

Marty

A very nice essay, but then I agree with everything you and your sources have said. I guess someplace in my mind I can see a case for pushing film, but I've never done it. What I'm not able to understand is why people push film when photographing scenes that do not require pushing. I know roll film; then get two cameras. Isn't it true that a properly balanced negative, if treated roughly in post-processing can also produce the same no shadows high contrast effect without pushing? And at least you still have a good negative if you decide later that the pushing fade is over.

 

[Arjay]

Thank you for this fascinating thread - being back to film after a long digital intermission makes me see exposure and developing with new eyes. However, here's a remark that caught my interest:

Negatives for scanning are not negatives for wet printing. You can make negatives that work well for both, but the ones that are very best for one won't be so suited to the other.

I don't intend to highjack this thread, but this topic is interesting for everyone who uses a hybrid workflow. I haven't found any hints for exposure/developing with reference to subsequent scanning.

Can anyone offer some links to other places that elaborate in greater detail about this topic, please?

 

[SebC]

Arjay,

I'm pretty new to developing and scanning, but I've found that consumer scanners struggle with very dense negatives - but you can always pull something pretty decent out of a negative that's a bit thin (but you do seem to lose midtones and detail over those that are properly exposed and developed).

 

[mfogiel]

My take on this is the following:
When you scan, what you really want, is not only to have the highlights and the shadows, but also all the gradual tonal passages in between. This is primarily, why it makes sense to overexpose slightly and keep your development time short, and/or ose a compensating developer on top of this. This way you get a negative which will scan ok as negative without clipping anything, and the histogram will fill completely your little chart in the scanner with a fairly full and gently rounded curve. This is a raw material, from which, mainly with just a slight contrast increasing pull of the curves in the midtones, you get a splendid tonally image. If your film is overexposed and overdeveloped, you risk some serious highlight compression, if it is strongly underdeveloped, the shadows will be compressed. I will post some examples now:

Slight overexposure, overdevelopment - Super Angulon 21/3.4, Rollei Retro 100. Tanol Speed

Underexposure and normal development - Nokton 50/1.1, HP5+, Prescysol EF

Slight overexposure and slightly shorter development - Summicron DR, Tri X, Prescysol EF

For a quick fix with minimal post processing, I would suggest Tri X @320 and Rodinal 1+50 or 100, this gives me an output that basically does not require any adjustments:

Summilux 50 pre ASPH, Tri X, Rodinal 1+50

 

[JPSuisse]

My take on this is the following:
When you scan, what you really want, is not only to have the highlights and the shadows, but also all the gradual tonal passages in between. ... This way you get a negative which will scan ok as negative without clipping anything, and the histogram will fill completely and have a gently rounded curve. This is a raw material from which, mainly, with just a slight contrast increasing you get a splendid tonally image..."

Hi all

I'm really enjoying reading the comments on this, and mfogiel, I really like your pictures AND comments AGAIN. Your quote above is exactly what I am trying to get!

Basically, my next experiment this weekend, will either be Tri-X at 320 and Neopan 1600 at, say 600 to 800. Then, I'm going to develop a more normal time.

@ SebC: I suspect one of the big unsaid things on this forum is that people who prefer thinner negatives just don't have a scanner with a high dynamic range. My Nikon 5000 handles contrastier negatives quite well.

@ Arjay: We amateurs ;-) are now moving ahead on this topic, it would be fun to see your images too. Next week I'll post both RAW and developed scans of my next experiment.

Anyway, once I get my negatives about what I like for scanning, I'm going to go back into a darkroom and try doing some printing on a grade 2 - 3 paper just to see, how my negatives are for printing. I am looking for a good compromise on scanning and wet printing. Because, to be honest, the digital is great for internet and sharing on the computer. But, in the end, the best prints for say hanging up in the office, house, etc. come out of the darkroom.

Thanks for all your guys' comments and cheers,

JP