methods for more contrast???

[markbarendt]

I'm too late, since Ralph already gave you the answer.
So perhaps a question in return: why do you assume straight curves of infinitessimal length?

I don't assume that.

What I do assume is that; a given film, in a given process, will provide give us an essentially fixed contrast/characteristic curve.

As long as film and process choice remains fixed, so does the predictability of contrast available along that curve.

Compressing highlights or shadows using exposure is as old as photography is. Have we already forgotten? Wow!

No I haven't forgotten, but that's just a placement choice and I do believe that it is truly problematic to "place" important subjects off the straight line.

 

[Q.G.]

Well, yes and no, Mark.
The decision to increase contrast is a decision to lose detail somewhere. If it were problematic, we wouldn't decide we want to increase contrast to begin with.

What and where we drop can be controlled shifting the scene up on the shoulder (if there is one) or down the toe. That last bit is what underexposing does.
By developing longer, the bits that are still recorded are shifted further up the scale again, stretching the range.

 

[eddym]

straight curves of infinitessimal length?

Isn't that a contradiction? Something that is infinitesimal probably cannot be seen.
Perhaps you meant, "infinite"?
:confused:

 

[markbarendt]

Well, yes and no, Mark.
The decision to increase contrast is a decision to lose detail somewhere. If it were problematic, we wouldn't decide we want to increase contrast to begin with.

Agreed, first decide what's important in the scene, then look at the scene and measure the SBR if we please to decide what film and process combo we think will give it proper contrast and to place exposure to clip/compress where we want.

What and where we drop can be controlled shifting the scene up on the shoulder (if there is one) or down the toe. That last bit is what underexposing does.
By developing longer, the bits that are still recorded are shifted further up the scale again, stretching the range.

I don't think underexposure is a good term here.

If we start with a EI 400 film (if developed normally) and change the process to say +2 development, EI 640 becomes a really good estimation of the "proper" exposure based on speed point.

So once we decide that the important bits of our scene will fit nicely on the curve of a +2 negative then our job at the camera is simply placement (and of course composition). i.e. getting the important bits placed on the curve.

To underexpose, IMO, you would need to shoot that EI640 speed point combo at say 800 or 1600 or 3200.

Underexposure, shooting past the tested speed point, would reduce the density of the negative and less density means...? :confused:

 

[Q.G.]

Isn't that a contradiction? Something that is infinitesimal probably cannot be seen.
Perhaps you meant, "infinite"?
:confused:

I did, yes.
Thanks for the correction.

 

[Q.G.]

[...]
I don't think underexposure is a good term here.

If we start with a EI 400 film (if developed normally) and change the process to say +2 development, EI 640 becomes a really good estimation of the "proper" exposure based on speed point.

So once we decide that the important bits of our scene will fit nicely on the curve of a +2 negative then our job at the camera is simply placement (and of course composition). i.e. getting the important bits placed on the curve.

To underexpose, IMO, you would need to shoot that EI640 speed point combo at say 800 or 1600 or 3200.

Underexposure, shooting past the tested speed point, would reduce the density of the negative and less density means...? :confused:

I think we're now only discussing semantics.
I say "underexpose", you say "shooting past the tested speed point" or talk about a different "IE".

Underexposure would indeed lead to less density. Less density means we can still print most of the scene, except the part of the scene for which less density equals no density.
It will also lead to a compression of tones in that part of the scene shifted off the straight part.

If we combine that underexposure (something that already changed contrast) with prolonged development, densities are restored, but the effect of underexposure on what parts of the scene are captured, and how, is not.

 

[markbarendt]

I think we're now only discussing semantics.
I say "underexpose", you say "shooting past the tested speed point" or talk about a different "IE".

Underexposure would indeed lead to less density.

And that is the reason the speed point is important to know and why using the speed point as our reference point for proper exposure is not just semantics.

Less density means we can still print most of the scene, except the part of the scene for which less density equals no density.
It will also lead to a compression of tones in that part of the scene shifted off the straight part.

Sure, but it's not necessarily making our lives easier.

And sure you should get stronger/more blacks in the print, but the compression of tones, as the curve flattens on toe or shoulder, resulting in a reduction in the separation/contrast.

Still and yet that choice to underexpose is just a placement choice.

If we combine that underexposure (something that already changed contrast) with prolonged development, densities are restored, but the effect of underexposure on what parts of the scene are captured, and how, is not.

From "box speed" this statement makes sense. This is the standard logic for the push/pull world, it's anathema for the expansion/contraction world.

The difference is in the general practical use.

Pushing/Pulling is for getting something usable from something truly under/over exposed, it's normally driven by needing faster or slower shutter speeds than the film in our pocket would normally give us. Ease of printing is a secondary consideration.

Expansion & contraction are for matching SBR to a planned film density range and in turn to a planned paper density range. They make a specific printing result easier.

The difference in use is much more than semantics.

 

[Q.G.]

Sure, but it's not necessarily making our lives easier.

Knowing what it does can indeed make our lives easier, because we then know what to do to get a result we are after, when we are after that result.

And sure you should get stronger/more blacks in the print, but the compression of tones, as the curve flattens on toe or shoulder, resulting in a reduction in the separation/contrast.

Still and yet that choice to underexpose is just a placement choice.

Yes it is.
Placing tones off the curve, make them unprintable, is enhancing contrast.

The compression of tones on the shoulder or toe is not the sum total of what you get. So what happens in those parts alone should not be taken to be the measure for whether this works or not.
So it would have been better if i hadn't mentioned the compression.

From "box speed" this statement makes sense. This is the standard logic for the push/pull world, it's anathema for the expansion/contraction world.

The difference is in the general practical use.

Pushing/Pulling is for getting something usable from something truly under/over exposed, it's normally driven by needing faster or slower shutter speeds than the film in our pocket would normally give us. Ease of printing is a secondary consideration.

Expansion & contraction are for matching SBR to a planned film density range and in turn to a planned paper density range. They make a specific printing result easier.

The difference in use is much more than semantics.

But is it?

Pushing does indeed enhance contrast. Just as expanding.

 

[Stephen Benskin]

Something to consider when dealing with film/developer combinations and their influence on contrast, are the variables the rate of development or development constant and gamma infinitely. Both can be derived from a contrast/time curve like the ones Ralph kindly provided.

Dev Const – High, Gamma Infinity – High -- Contrast builds quickly, proceeds at a high rate and contrast continues to build up to a high value.

Dev Const – High, Gamma Infinity – Low -- Contrast builds quickly, but soon slows reaching its limit at a low value.

Dev Const – Low, Gamma Infinity – High -- Contrast builds slowly and increases at a slow rate, but with time, it is able to build to a high value.

Dev Const – Low, Gamma Infinity – Low -- Contrast builds slowly, increases slowly and levels off at a low value.

Films with high constants reach normal contrast fairly quickly. The developer may have insufficient time to adequately develop the sub latent image in the halide crystal which can result in lower effective film speeds. A 400 ISO film could have an EFS of 100 in a high velocity film/developer situation.

A lower velocity combination would reach normal contrast with sufficient time to allow for more complete development of the shadow values. This will more than likely result in a film with an EFS closer to the ISO.

A film with a high gamma infinity makes for a versatile film. It is able to handle a greater range of pushing. However, when pushing for speed, a low constant/ low gamma infinity film would work best. The longer development times will give greater speed potential and the lower gamma will restrict excessive contrast.

Films with a low constant are good for less precise systems or for an amateur just learning to process film. The allowable error in development is higher than with a high constant film/developer.

 

[markbarendt]

When we print, and we use too "hard" a contrast the print looks ugly, we get a different kind of ugly when we print to "soft".

It's the steepness of the curve that matters here, the rate of change from one tone to the next, not how many tones there are on the negative.

Exposure doesn't change the contrast rate/curve steepness.

Exposure determines placement, which part of the curve we use.

If we plan on a +2 process and shoot the same scene, in the same light, using a 400EI film at ~640 we'll probably get a full curve on the neg, if we shoot the same film at 1600 we are just moving our exposure down the curve some and our exposure may not get up to the shoulder.

The print from the neg shot at 1600 will look darker than the one shot at 640, not more contrasty.

 

[Steve Sherman]

When we print, and we use too "hard" a contrast the print looks ugly, we get a different kind of ugly when we print to "soft".

It's the steepness of the curve that matters here, the rate of change from one tone to the next, not how many tones there are on the negative.

Exposure doesn't change the contrast rate/curve steepness.

Exposure determines placement, which part of the curve we use.

If we plan on a +2 process and shoot the same scene, in the same light, using a 400EI film at ~640 we'll probably get a full curve on the neg, if we shoot the same film at 1600 we are just moving our exposure down the curve some and our exposure may not get up to the shoulder.

The print from the neg shot at 1600 will look darker than the one shot at 640, not more contrasty.

Please, don't use the term "we" as I for one find your reasoning unusual if not confusing.

 

[markbarendt]

Please, don't use the term "we" as I for one find your reasoning unusual if not confusing.

Fair enough Steve on I vs. we.

As for being unusual, it doesn't bother me to be considered so.

If I'm wrong, I really want to know but the definition of contrast seems to be a moving target and saying film underexposure increases contrast seems to me to be saying "ignore the man behind the curtain" (the film and paper curves).

This doesn't make any sense to me. I know it also confuses others.

A film's response to a given amount of light doesn't change unless the development process changes, does it?

The paper's response curve similarly doesn't vary without some change, does it?

Choosing a film curve and exposure carefully to match the SBR we want, should provide the best separation of tones (contrast) possible on the film, correct?

Underexposure, without any other change, reduces total density/overall negative contrast, right?

An intentional reduction in negative density, without a corresponding change in the printing process, means placing all the subjects in a darker zone of the print and the paper's black point doesn't move, so that's actually a reduction in contrast, right?

Sure, a change in the print exposure or print contrast grade is always an option, but underexposure of the film doesn't increase the contrast of the result, we have to make that choice during printing, right?

What am I missing here?

 

[Steve Sherman]

Fair enough Steve on I vs. we.

Let me first say that my answers are subjective and based on my opinions, that said, for 25+ years my primary focus in photography has been in B&W silver gelatin, silver chloride or Pt. / Pd. printing, both contact and enlarged prints. So, the following commentary is based more on practical experience then to absolute principles and theories which have been generalized and accepted for decades.


A film's response to a given amount of light doesn't change unless the development process changes, does it?

Yes it does, predicated on where the tonalities fall on the curve, if tonalities were to fall entirely on the straight line, then the answer would be no. In my opinion that would be a very rare set of circumstances.

Choosing a film curve and exposure carefully to match the SBR we want, should provide the best separation of tones (contrast) possible on the film, correct?

Agreed, however, my interpretation of a scene (SBR) would be markedly different than Brett Westons, I'd like to think it would come down to personal vision /style, neither of us being right or wrong, just different.

Underexposure, without any other change, reduces total density/overall negative contrast, right?

On the face this statement is true, however, most everyone here has correctly coupled less exposure and more development as a means to effect higher contrast. Personally, I do not use the terms "under or overexposure" as I believe those make reference to a constant and in this context the constant is dictated by one's desired look, rather I use the terms "less or more" pertaining to exposure and development.


An intentional reduction in negative density, without a corresponding change in the printing process, means placing all the subjects in a darker zone of the print and the paper's black point doesn't move, so that's actually a reduction in contrast, right?

Same question and answer as above


Sure, a change in the print exposure or print contrast grade is always an option, but underexposure of the film doesn't increase the contrast of the result, we have to make that choice during printing, right?

Negative exposure / development and paper contrast / processing is a multi faceted relationship that can be significantly shaped to one's personal likes and style, it seems to me that so many posters here site "one line bullets" striving to make their point if not pound their chest a bit. That said, at the core of their statements many are correct, however, in practical application there are so many other variables which impact the OP question of "methods to effect more contrast"

As I've said so many times, the best of the internet can be the worst, so much free information, not always accurate and the OP is left to either decipher what is accurate or accept the best made argument.

Cheers!

 

[markbarendt]

A film's response to a given amount of light doesn't change unless the development process changes, does it?

Yes it does, predicated on where the tonalities fall on the curve, if tonalities were to fall entirely on the straight line, then the answer would be no. In my opinion that would be a very rare set of circumstances.

My point is not that the curve is straight, just that it is predictable; hence a given amount of light will get a predictable response.

Choosing a film curve and exposure carefully to match the SBR we want, should provide the best separation of tones (contrast) possible on the film, correct?

Agreed, however, my interpretation of a scene (SBR) would be markedly different than Brett Westons, I'd like to think it would come down to personal vision /style, neither of us being right or wrong, just different.

Absolutely.

Underexposure, without any other change, reduces total density/overall negative contrast, right?

On the face this statement is true, however, most everyone here has correctly coupled less exposure and more development as a means to effect higher contrast. Personally, I do not use the terms "under or overexposure" as I believe those make reference to a constant and in this context the constant is dictated by one's desired look, rather I use the terms "less or more" pertaining to exposure and development.

I agree that underexposure is a poor term for a planned event.

The statement is still true, less than full exposure begets less contrast.

In my view the imperative driving the need to change EI, is the need to match the new contrast range's speed point.

As I noted much earlier in the thread, a 1/3 stop, even a 2/3 stop change in the real speed point doesn't always force us to change our exposure, many times it's not even practical. We can simply use a +1 process with normal exposure settings.

Sure, a change in the print exposure or print contrast grade is always an option, but underexposure of the film doesn't increase the contrast of the result, we have to make that choice during printing, right?

Negative exposure / development and paper contrast / processing is a multi faceted relationship that can be significantly shaped to one's personal likes and style, it seems to me that so many posters here site "one line bullets" striving to make their point if not pound their chest a bit. That said, at the core of their statements many are correct, however, in practical application there are so many other variables which impact the OP question of "methods to effect more contrast"

In photography many common tasks get packaged together. “Pushing and pulling”, and “underexpose and overdevelop” are great examples.

These concepts get packaged so tight that their process becomes dogma, many people think they have to be used together.

Dogma is easy, but it's not always right.

 

[Q.G.]

In photography many common tasks get packaged together. “Pushing and pulling”, and “underexpose and overdevelop” are great examples.

These concepts get packaged so tight that their process becomes dogma, many people think they have to be used together.

Dogma is easy, but it's not always right.

Uhm...
Just because you can get a hint of what happens when you underexpose and overdevelop without doing both doesn't mean that what you call "dogma" isn't right.

It, of course, is.
You say that you can overdevelop without needing to adjust exposure, and get higher contrast that way. Good. So overdeveloping can increase contrast.
Once you have run out of the limited margin you have doing that without adjusting exposure, you too will have to do that "dogma" thing.

 

[markbarendt]

We can simply use a +1 process with normal exposure settings.

Opps, didn't proof well enough and used we,sorry Steve.

 

[stradibarrius]

Steve this is a good answer for "ME". When I originally asked the question, I had no idea that it would get such a big and complicated response. The thread has taken on a life of it's own and that is not bad but much of the information is too much for me personally. Steve's response in #88 has information that makes sense to me.
Steve if I understand your response, at a given exposure, the light can have more or less contrast depending on the scene...correct? So a given light value will fall at a different point on the curve based on the contrast of the scene??? Correct?

I have been reading Ralph Gibson and he over exposes and over develops to achieve his interpretation of a high contrast scene. Iknow that many of you that are participateing in this discussion know what you are talking about because I can look at your gallery and see what you produce. I may not really understand your answers because it is beyond my level at this point but it makes me think. Steve's response resonates at this point in my journey.

My most recent book "Darkroom" has many different "Greats", including Gibson. Their individual approach shows that many of them don't seem interested in the "nuts and bolts" only in how to get the results that they see in their eye.

 

[markbarendt]

Once you have run out of the limited margin you have doing that without adjusting exposure, you too will have to do that "dogma" thing.

Development changes; -1, +1, etcetera... are used adjust the length/height of the curve, the contrast.

The choice of development: -1, +1, etcetera... determines how much contrast is possible. The characteristic curve shows this

Exposure choices just place certain subjects at certain points on the film's curve, it doesn't change how much contrast is available.

It is my understanding that the straight line portion of any film provides the most contrast on the curve, this appears to me to be true for both the separation of individual tones and for contrast in total.

Carefully matching the straight line portion of the curve to the SBR should provide the highest possible contrast from any film.

This careful match is what I might call shooting for a "full exposure" because the SBR "fills" the straight line.

Less than full exposure (what I might call an underexposure) results in negatives that don't fill the straight line so they hold fewer tones than that film curve is designed for.

Example;

My Delta 400, in my +1 developing process, with my metering style, will generally give me a full exposure if I shoot at EI500; the shadows fall at the same place as when I shoot Delta 400 at EI400 and develop "normally".

Moving from the "normal" EI400 to the +1 EI500 is not underexposure, it's just matching the film's curve to my metering method.

If I shoot my +1 process Delta 400 at EI640 (instead of it's tested 500) I get less contrast overall, fewer tones on the film, and less shadow detail because I chose to place my exposure lower on the curve.

I'm happy to "underexpose" and give up some shadow detail and overall contrast when I need a faster shutter speed, just to get a workable shot, but the contrast in the negative gets lower.

I'm happier when I can use my +2 process when I need to shoot at EI640 because that is where it tested at.

I don't normally use a +3 process for Delta 400 so if I need to shoot at EI800 or 1600 I just accept that the underexposure will get me thinner and thinner negatives with less and less contrast.

My point is that the most contrast is available at the film's tested speed point, underexposure past that point reduces the films contrast.

 

[Q.G.]

Development changes; -1, +1, etcetera... are used adjust the length/height of the curve, the contrast.

The slope of the curve, yes.
Increased development also increases density, pushing up the scene towards D-max. For every X amount of light the film is exposed to, the photographic effect/density will be higher.
To be able to continue to use extra development as a way to increase contrast, you have to stay away from D-max. So you underexpose.

 

[markbarendt]

Gamma infinity sneaks in there too. There comes a point when the base fog starts keeping up with or overtaking the increase in density.

When you say underexpose, what do you mean? What is the reference point you use to define a normal exposure?

 

[Q.G.]

Still the semantic game then?
You, like anybody else since the days photography was invented, all through the days people studied the behaviour of light sensitive emulsions, turning it into a much too belaboured 'art', do know what is meant.

 

[Steve Sherman]

Steve this is a good answer for "ME". When I originally asked the question, I had no idea that it would get such a big and complicated response. The thread has taken on a life of it's own and that is not bad but much of the information is too much for me personally. Steve's response in #88 has information that makes sense to me.
Steve if I understand your response, at a given exposure, the light can have more or less contrast depending on the scene...correct? So a given light value will fall at a different point on the curve based on the contrast of the scene??? Correct?

I have been reading Ralph Gibson and he over exposes and over develops to achieve his interpretation of a high contrast scene. Iknow that many of you that are participateing in this discussion know what you are talking about because I can look at your gallery and see what you produce. I may not really understand your answers because it is beyond my level at this point but it makes me think. Steve's response resonates at this point in my journey.

My most recent book "Darkroom" has many different "Greats", including Gibson. Their individual approach shows that many of them don't seem interested in the "nuts and bolts" only in how to get the results that they see in their eye.

Yes, I believe the scenario you are imagining is depending on lighting conditions where a given value can fall at different points on the curve predicated on what exposure and development is dictated by scene contrast

As far as the original question is concerned, that is what most gets me involved with these discussions as you say the thread takes on a life of it's own, that is to say it evolves to something completely beyond what the OP was looking for. IMO, many times allowing a forum for photogs to show how much they know, or in some cases how little they know.

Originally Posted by markbarendt
In photography many common tasks get packaged together. “Pushing and pulling”, and “underexpose and overdevelop” are great examples.

These concepts get packaged so tight that their process becomes dogma, many people think they have to be used together.

Dogma is easy, but it's not always right.

The above statement, I know Mark has a good understanding of the process, I believe I know the point he is trying to make, however I am not certain and there in lies the dilemma for others whose understanding maybe more limited.

I don't consider myself a very technical person, rather one who has a working understanding of the films and chemistry I use and how to get the results I want, most of the time. Make no mistake, my waste basket has plenty of prints and negatives in it.

 

[markbarendt]

Sorry for not being so clear, I'll try again but no promises.

My point is "why make it hard?"

If all I want is a little more contrast on film, all I need is a little extra time in the developer.

If the only downside is that I end up 1/3 of a stop overexposed I'm going to be pretty happy and I'll figure out the exposure I like in a roll or two.

When someone has learned enough to be able to ask a good question about the process, the need for generalizations is passing.

 

[Q.G.]

A good question was asked.

Good answers were given too.

I don't understand, though, why you think that those good answers aren't good, because

If all I want is a little more contrast on film, all I need is a little extra time in the developer.

If the only downside is that I end up 1/3 of a stop overexposed I'm going to be pretty happy and I'll figure out the exposure I like in a roll or two.

i.e. eventually ending up doing what you were arguing against.

The fact that you can indeed botch things, because you only want "a little more", and get something you find acceptable doesn't make the non-botch procedure a flawed generalisation (or "dogma" as you called it).

The thing is that some things are both so simple and 'old hat' that the only good answers cannot be anything else but extremely commonplace ("generalizations", you call that).

 

[markbarendt]

Q.G.

Who says they will end up where you or I think they will?