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High contrast film?

Necator

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Aug 31, 2008
Messages
138
Location
Broendby, De
Format
Multi Format
Hi,
A couple of months ago I began developing my own B&W film. I do not have a darkroom, so I use a changing bag and the (at least here) controversial approach of scanning my negatives, and adjusting them in Lightroom before I order prints online.

It is thus pretty easy to adjust the contrast, but I would like to do it right (ie contrast should be where I want it on the negative). Is that achieved through film selection, development technique, choice of developer or a combination?

I have shot mostly Fomapan 100, developed in Rodinal 1+25 or 1+50, and used the development times from the massive dev chart. So far the contrast has been lower than I was aiming for.

What are your thoughts?

Henrik
 
I had the same issue (there was a url link here which no longer exists)
 

The answer is all of the above. Some films (e.g. KB25) are more contrasty than others. Some developers produce more (or less) contrast than others. Developing longer produces increased contrast - shorter produces less contrast. More vigorous agitation produces more vigorous development, and hence contrast. There are many books that discuss the Zone System, which treats this issue rigorously. In general, you need to experiment or make tests until you get a satisfactory combination. If you use roll film, you try to get things so that most negatives (scenes with average lighting and average subject contrast) need minimum or no adjustment (or print on grade 2 or 3 paper). Of course, some negatives will not fit into that category. They will have harsh or overly flat lighting or some extreme of subject contrast. Those will be difficult, but you can usually get an acceptable print if they are exposed correctly. If you use sheet film, you can use the full Zone System approach, but many use the same technique as roll film users.
 
Kodak Plus-X has great contrast.
 
I use Kodak Tri-X at 400 ISO and XTOL full strength and follow the directions. It comes out bang on every time. Not high contrast unless the scene is high contrast. Do you want high contrast from a low contrast scene?

Steve
 
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I actually like relatively low contrast in my negatives for scanning: it's easier to increase contrast in software than to decrease contrast...
If contrast is WAY too low, you should look at both the contrast of the scene you photograph (a low contrast scene will not give high contrast negatives) as well as development time: thin&low contrast negatives can be improved by increasing development time...
 
Contrast of the negative is controlled by development. The longer you develop, the higher the contrast.

Changes in development affect the effective speed of the film. So as you shorten development, you have to increase exposure.

Rodinal is a "speed losing" developer. To develop to "box speed" on most films, you have to develop it to moderately high contrast (contrast index of like 0.65 to 0.7 or more). So either lower your developing time and EI, or use a developer than maintains film speed (say D-76 or HC-110), or is "speed enhancing" (say, XTOL, DD-X, or Microphen).

Note that for a scanner, the "challenge" isn't the contrast, per-se. It's how dense the highlights of the negative are, at a certain point it can't see through the dense negative, or gets noisy. But, that's pretty much free with reducing development time and EI.
 
Thank you all for your input. Mark, thank you for mentioning Ansel Adams "The Negative", I have now ordered it from my local library, should be an interesting read.

Looks like I should experiment with longer development times (longer than the ones listed in the massive dev chart). I was not aware that Rodinal was a speed losing developer, that could explain my flat looking negatives. I have considered getting some HC-110, not as a replacement for Rodinal, but rather as supplement. It is also said to be better at handling Tri-X and Tmax type films.

Just out of curiosity. I have noticed that the development times (massive dev chart) for Fomapan 100 in Rodinal are a lot shorter than for e.g. Agfa APX100 or Ilford FP+. Are films really that different? For APX100, the development time is almost twice as the one for Fomapan 100.
 
Actually, developing Rollei Retro 100 ("rebranded" APX-100) at box speed is very well possible in Rodinal, I wouldn't worry too much about that. I use 12.5 minutes at 20C and get perfect negatives (On a sunny day I shot a yellow wall which was in shade with Zone 0-X exposure and got great results). If I test a film or a shutter, I always use the same wall at my home, on a sunny day around noon when the wall is in shade, to minimize variability.
 

It could be that the Fomapan is a film made with less hardened gelatin relative to the other more modern yet still traditional (i.e. non-tabular) silver films.

Hardened gelatin offers a much slower expansion and diffusion rate to the devloping agent when the developer is poured over the film.

Hardened gelatines on the other hand are much more resistant to protecting the image forming silver from damage, or being harmed by higher temperature development.
 
avandesande said:
My experience with fomapan was that it was a very 'flat' film.
Click to expand...
Please, explain. Fomapan 200 is highly valued by alt process printers who need a film that can produce significant contrast. I have no problem with getting proper contrast and density off my negatives to yield excellent platinum and gum bichromate prints, and salt, albumen and carbon are not out of the question either. This is accomplished with "expansion" development (i.e. extending the development time without changing the exposure). If you are finding the film to be too "flat", then perhaps you should change your development time.
 

By your hypothesis, then, Fomapan should have more contrast, not less, as from your explanation we deduce that the more hardened gelatin in other films will impede development.
 
I just love shooting film, and love this site . I started out by wondering how I could increase contrast on my negatives, and before I know it, I'm learning about the Zone System, reading Wikipedia articles on film development and silver halides to understand the differences between expansion and push processing. I was able to put the pieces together, although it did not prevent me from dreaming about Zone systems and development the whole night
 
Necator, I can happily advice the book "The Negative" from Ansel Adams. It helped me tremendously last year when I started up developing my own B&W negs, made me understand things much better
 
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