Evaluate this advice

[traveler_101]

I've been shooting film and developing the negatives for just about three years. I'm still trying for some time to get my head around what ISO to shoot different films at in order to get certain effects, especially to increase contrast or to deal with shooting in bright sun which gives a washed out look at times or to shoot in darker conditions. Seeing also that people regularly "rate" films at x/2 when the stated ISO is x has intrigued and confused me. I should say also that I don't wet print (unfortunately)--just scan negatives on a Epson flatbed with as little processing as possible. Some time ago in response to a question about when to "push" and "pull" film, someone (on a different forum) sent me the following advice. Is he on the right track? Thanks in advance.

"Pulling film is normally defined as developing less. It has nothing to do with the exposure. For all practical intents and purposes, exposure and development have nothing to do with each other. (There is some very small effect, but it is too little to be concerned with.) The amount of exposure controls how much shadow detail one has; the amount of development controls how dense the highlights are and how much contrast there is. Period. When there is a high range between shadow and highlight, less development is used to keep the highlights from blowing out (becoming unprintable while keeping the full range). Pushing and pulling, in terms of changing ISO's, doesn't actually exist in real life. It's just a matter of managing the contrast ratio, after the fact, or as part of a zone system calculation."

 

[Ranchu]

That's true, as I understand the topic. If you look at film/development curves that show curves for different development times, all that changes is the contrast...with the shadows staying put, the highlights going up further and further as development time increases. The exposure you choose slides the scene up and down on that developed contrast curve.

What pushing does is underexpose the film and then overdevelop it so the increased contrast from the overdevelopment brings the midtones up, so the picture looks OK. At the same time the midtone density goes up, the highlight density does too, which limits how far you can push, as the highlight density can become difficult to print or scan.

 

[Roger Hicks]

The advice is far better than most you will get, but usable speed does vary, especially with heavily curtailed development: this is where I disagree with "There is some very small effect, but it is too little to be concerned with". My own view is that it is noticeable, though not very important. The word "pulling" is indeed all but meaningless, though: it is just underdevelopment.

There are however times when you may be willing to put up with less shadow detail and higher contrast in return for more density in the mid-tones, i.e. pushing.

In neither case are you affecting the true ISO speed

You may or may not find this useful: http://www.rogerandfrances.com/subscription/ps neg density.html

Ranchu's "Exposure slides the scene up and down on that developed contrast curve" is an excellent way of describing the overall effect. Those who overexpose and underdevelop (mistakenly calling it "pulling") are merely sliding the exposure further to the right on a less steep curve.

Cheers,

R.

 

[Ko.Fe.]

I've been shooting film and developing the negatives for just about three years. I'm still trying for some time to get my head around what ISO to shoot different films at in order to get certain effects, especially to increase contrast or to deal with shooting in bright sun which gives a washed out look at times or to shoot in darker conditions. Seeing also that people regularly "rate" films at x/2 when the stated ISO is x has intrigued and confused me. I should say also that I don't wet print (unfortunately)--just scan negatives on a Epson flatbed with as little processing as possible. Some time ago in response to a question about when to "push" and "pull" film, someone (on a different forum) sent me the following advice. Is he on the right track? Thanks in advance.
...

Sorry, I can't evaluate something which I couldn't understand. ISO and zone system, what a...

But I would like to help you with different approach.

Where are multiple issues described in your initial post.

Print or scan it doesn't really matter. Negative is intermediate form to get final result. Analog print or digital scan, both required processing. So, doing minimal processing of scan for final image is... wrong!
I have V500 and scan b/w as b/w color 48-bit tiff, this file format allows me to adjust and fine tune the image.
If you have good negative it is only intermediate form, you are getting final contrast of the image in the darkroom by changing of filters or by the Lightroom application by adjusting not only contrast, but color temperature as well, for example.

If you want more details in the dark you must have correct exposure.
You are achieving it by calculating of duration for selected aperture and ISO of your film.

ISO of your film is very personal thing 🙂
I went through some current films recently and where are some good ones like T-MAX, HP5+, TRI-X. In terms how good results from them with box label ISO and developer you are using. But some films aren't so accurate with declared ISO. Maybe just in particular personal case. And at least with particular developers.
For example, I struggle to get rich tones with Kentmere 400 @400 in x-tol. But once I lowered it to @200 - what a lovely film for scans!

Back to dark, bright thing. In general you are not going to get better results with "pushing in the dark". We rate 400 @1600 only because we can't use tripod 😉

Shooting in bright sun is less difficult and much more easier comparing to digital, IMO, in terms of how good the final result is for tones and contrast.
All you have to do is to have correct exposure.
Measure the light right, skip this "zone" thing for now. I highly recommend light meter free app on the mobile phone. It is WYSIWYG on the negative.
Or use cameras with TTL measurement. I use XA and FTb, have Bessa-R and OM-10 before. All of them are measuring it right in the bright light.
Make sure you have good lens and hood in it, you are using something like Leica. If you shoot into the sun, you'll get "washed out results" just because of how it works with the optics.

If you are using external meter, learn how to measure it right in different situations. You don't need fancy, bloody expensive meters if you understand the exposure. And don't measure all of those "zones". Measure where it is most important part of the picture and darkest, lightest parts.


In short terms:

Take it under correct exposure, use filters to have more even negative and process the TIFF scan file for fine-tuned results.

Use PUSH if you can't use tripod, use PULL if you aren't satisfied with negative at claimed by manufacturer ISO.

Take it easy! Sunny 16 actually works!

 

[Roger Hicks]

A further thought on scanning: overdevelopment may very well make the highlights of the negative too dense for the scanner to penetrate, resulting in "blown" (clear white) highlights in the final image. This is why underdevelopment is safer than overdevelopment for scanning.

Modest overexposure (maybe a stop) will also give more differentiation in the shadows (the thinnest part of the negative), as you are no longer relying on the "toe" of the curve where quite considerable increases in exposure result only in modest increases in density.

Gross overexposure (more than about 2 stops) may also give excessively dense negatives and blown highlights, even with normal development.

ISO speeds are for the most part absolutely reproducible, but they do vary in different developers: the box speed is normally in a middle-of-the-road developer such as ID-11 or D-76. A film that is ISO 400 in one of these may rise to ISO 650 or better in a speed increasing developer or fall to 250 or less in a fine-grain developer. Also, an ISO speed is a reproducible scientific criterion: the EI you choose is a personal artistic choice, based on your equipment and your technique. If you don't mind a long read, try http://www.rogerandfrances.com/subscription/ps iso speeds.html The following quote is taken from it:

Even if they are imperfect, ISO speeds are a lot better than the Bad Old Days when speeds were set by the marketing department, not by scientific test. They are also a lot better than the maunderings of those who say "Of course, in the real world..." In their particular real world, maybe; but each photographers effectively inhabits his or her own particular world, shooting different subjects with different cameras and different metering techniques.

Cheers,

R.

 

[Godfrey]

...

"Pulling film is normally defined as developing less. It has nothing to do with the exposure. For all practical intents and purposes, exposure and development have nothing to do with each other. (There is some very small effect, but it is too little to be concerned with.) The amount of exposure controls how much shadow detail one has; the amount of development controls how dense the highlights are and how much contrast there is. Period. When there is a high range between shadow and highlight, less development is used to keep the highlights from blowing out (becoming unprintable while keeping the full range). Pushing and pulling, in terms of changing ISO's, doesn't actually exist in real life. It's just a matter of managing the contrast ratio, after the fact, or as part of a zone system calculation."

This is a good rule of thumb, but it's not the whole story.

For negative film, "expose for the shadows, develop for the highlights" is a better and mostly-equivalent rule of thumb purely because it's simpler and easier to remember. It doesn't tell the whole story either.

- Exposure, based on the film's native sensitivity curve, establishes how much density and dynamic range you'll get with "standard" development. If you use the manufacturers' guidelines for sensitivity and development, you'll get a "standard" negative with the dynamic range and reference density* as listed in the film data sheets. The manufacturers' specs are intended to place optimum exposure and processing such that the largest portion of the film response is in the linear portion of the output density curve, from fully exposed to clear (that is, from white point to black point).

* Reference density: Density is the amount of light absorption that a processed piece of exposed film exhibits. Every film has a data sheet that lists how much density is expected with a standard amount of exposure and standard development. Photo labs use this reference density and pre-exposed (by the manufacturers) clips of the film along with a densitometer to calibrate and control their processing machines.

- Changing ISO shifts the density you'll get with standard development along the output density curve. It modifies the dynamic range, essentially, due to development changes from standard necessary to regain density at the reference points.

- In development, the overall developer-time-temperature combination sets the baseline for how much exposure will build density to a reference X. In other words, you expose a particular film with sensitivity rated N at the reference exposure for middle tone and use the standard development process, the overall developer-time-temperature combination should result in an output density that matches the reference density.

- BUT when you're push or pull processing, or using non-standard developers, or non-standard time and temperature, or non-standard agitation technique, you shift the density build-up along the curve.

Example:

Let's say that a film is rated ISO 200 in D76, standard dilution at 68° for five minutes with standard agitation. Presuming exposure of a reference grayscale chart, this should place the output densities from white point to black point in the linear portion of the processing curve.

Now, the situation you're shooting is contrasty so you'd like to flatten the contrast a bit. How do you do that? Density is (to first order) built by time in development, so you overexpose the film and modify the processing curve. Rate the film at ISO 100 for exposure and either dilute the developer, reduce the processing time, reduce the processing temperature, or some combination of all three. This allows the low values to be fully developed without blocking up the high values. You've lost some dynamic range, but you've placed the exposure into the right part of the processing curve to fit your subject's needs.

Consider the opposite situation: you have a flat scene that is going to need some additional contrast to make it shine. Presuming that ultimate shadow detail isn't essential, underexpose and overdevelop to achieve the goal—you rate the film at ISO 400, and increase the processing time, increase the processing temperature, or some combination of the two (it's usually hard to increase the developer concentration and get predictable results). The output densities should show a reduced dynamic range from shifting the exposure up the processing curve, but that's exactly what you wanted to match the flat-lit scene.

A lot of words, I know. To boil it down to a usable rule of thumb:

basic rule: Expose for the shadows, develop for the highlights.
to reduce contrast: Add exposure, reduce development.
to increase contrast: Reduce exposure, increase development.
​

The best way to really get a handle on this is to pick one or two films, one or two developers, fix a couple of standard processing methods for different ISO ratings, do a lot of experiments, and observe the results carefully. With consistency in setting exposure and processing the film, you'll get the hang of it quickly and know what you need to do to get the results you want.

G

 

[Godfrey]

A further thought on scanning: overdevelopment may very well make the highlights of the negative too dense for the scanner to penetrate, resulting in "blown" (clear white) highlights in the final image. This is why underdevelopment is safer than overdevelopment for scanning.
... [/I]

Yes, scanning throws another twist into the game. My standard exposure and processing has all been targeting scanning since the early 1990s.

I rate my film at double the nominal ISO, dilute the developer to allow a longer development time, and minimize agitation. This produces a slightly-thinner-than-reference density negative with plenty of shadow detail and unblocked highlights.

My target in scanning is to capture all the data on the film. Then I apply black point, white point, and curves adjustments to express the tones I'm looking for.

G

 

[Juan Valdenebro]

Hi,
He's a bit wrong...
If you want to control contrast under direct sun, it's true you should underdevelop for keeping the whole scene's tonal range (contrast) inside film's / paper's / scanner's usable ranges without missing information that was present in the real world.
But it's wrong exposure and development are not related... In the particular case just mentioned, a direct sun scene, you'll have parts of your image under direct sunlight, and parts of them in the shades... Unless you want a B&W look close to color slide film (high contrast, blocked shadows), the way to make such weather visible in a natural way in B&W, is doing a short development AND a generous exposure to get enough detail in those parts of your frame where direct sunlight didn't hit.
If you're happy with x development time for overcast days, you can do this: shoot a test roll under direct sun with irrelevant frames including subjects in the sun and in the shades... For every scene expose three times: at box speed, at +1 and at +2. Then develop half the roll with a development time that's 20% shorter than your standard for soft light scenes. And then develop the other half with a development time that's 40% shorter than your standard for normal contrast scenes.
Then, you'll have all you need in your hands: with your camera, your metering, your exposure and your development, you'll be able to see what your scanner can get, and you'll decide what YOU like for direct sun.
You can expect +2 shots from the second half of the roll to be the best ones, with a real warm mood close to human vision.
Cheers,
Juan

 

[traveler_101]

https://www.flickr.com/photos/93975264@N05/15745654998/in/photostream/lightbox/



Are these "blown highlights" on the church to the left and above the door? I over-exposed on purpose (probably by metering the brick pavement) in order to capture the feeling of the late afternoon light hitting the building.

I shoot this TX at box speed and developed in D-76 at suggested time. Is there something wrong with that?

 

[traveler_101]

https://www.flickr.com/photos/93975264@N05/15932341202/in/photostream/lightbox/

This one is very unsatisfying photograph. The tomes are all washed out. I wanted to feel the earth.

I see that I shot this at TX 400 @ 200; probably because I read that one preserves better detail by overexposing. i followed normal development time and routine in D-76.

 

[Corran]

Whoa, that looks way overdeveloped to me, and/or overexposed.

The church looks fine but maybe slightly overdeveloped.

I would pull your development time by 15-30%. The key about development is sticking to a development style/technique and figuring out your best time (and ISO!). While the data sheet might say xyz, your agitation, or any number of things, could cause excess contrast and therefore lessening the development isn't "pulling" so much as dialing in your personal technique.

I find that the adage to shoot at half the ISO given by the manufacturer to be terrible advice. It completely depends on the image, the intended usage (scanning/wet printing), developer, film, etc.

 

[Godfrey]

This one is very unsatisfying photograph. The tomes are all washed out. I wanted to feel the earth.

I see that I shot this at TX 400 @ 200; probably because I read that one preserves better detail by overexposing. i followed normal development time and routine in D-76.

Both of the images you posted seemed overexposed/overdeveloped/scanned with too contrasty a curve to my eye. But without seeing the negatives, I have no idea what you might be able to get out of them with a little bit of adjustment to the scan settings and some good image processing.

G

 

[Ranchu]

way too contrasty, but you are essentially trying to take a picture of a lightbulb set into a black painted wall. There are no midtones in the second picture, you can't generate them in development. If you're using epsonscan make sure you've set 'autoexposure' iin configuration to the lowest level, it just adds an s curve you don't want. I wonder if KM-25 will pop in to tell us how special pros are.

http://www.rangefinderforum.com/forums/showthread.php?t=94126

 

[Ranchu]

I wanted to mention this book, it's the best. I have the second edition...

http://used.addall.com/SuperRare/su...reRareBook&store=Powells&store=Wbm&store=ZVAB

 

[Dwig]

...
ISO of your film is very personal thing...

Since this has been a bit of a technical thread, I have to note that technically this statement is quite incorrect.

The ISO of a particular film can't be changed or altered by any one or any organization other than the ISO, period. Any personal speed rating is your personal Exposure Index (EI).