Pushing, Pulling and contrast

[Alan Klein]

If I want to change the contrast I'm getting on color film, what would I do when shooting and how to handle when processing?

Negative color film: ??

Positive chrome film: ??

 

[cliveh]

Wait for the lighting contrast to change to what you want before you take the shot.

 

[Gerald C Koch]

Because color film contains a separate layer for each primary color it does not respond well to pushing or pulling. What happens when pulling is that the bottommost color layer gets less than the expected amount of development. This causes a loss in the color response of the film to that color. The reverse happens with pushing. The topmost layer gets more than expected development emphasizing the particular color for this layer. Concisely with either pushing or pulling you get a color shift in the film.

Some positive color films normally exhibit greater contrast than others. I personally do not use slide film so perhaps others can make a suggestion.

 

[Poisson Du Jour]

Negative color film: step overexpose in 0.5 and keep notes. Not a lot of C41 emulsions are of such high contrast to cause difficulty other than baseline adjustments of exposure that are normal for the scene you are shooting and familiar with.

Positive chrome film: Two options: expose the film in conditions it is known to respond best to e.g. Velvia, Provia et al, diffuse conditions, or bracket overexposure in 0.3 increments (by dial or ISO). You must know the dynamic range of the chrome film you are using in order to make a value-based judgement on over- or under-exposure (but especially overexposure). Guessing isn't an option. Use a spot meter or something that can be used to pick over a scene presenting as challenging.

Pushing and/or pulling film essentially compromises the results, especially so with chrome emulsions so the best course of action is to understand, through experimentation, how one particular film responds in several different lighting scenarios, and over- and/or underexpose (e.g. rate at an EI other than box speed). Importantly, keep notes of what you are doing as these will come in handy when the chromes are laid out on the lightbox.

 

[MartinP]

Because color film contains a separate layer for each primary color it does not respond well to pushing or pulling. What happens when pulling is that the bottommost color layer gets less than the expected amount of development. This causes a loss in the color response of the film to that color. The reverse happens with pushing. The topmost layer gets more than expected development emphasizing the particular color for this layer. Concisely with either pushing or pulling you get a color shift in the film.

Some positive color films normally exhibit greater contrast than others. I personally do not use slide film so perhaps others can make a suggestion.

This explanation using the depths of the layers in the film is interesting. The development time for C41 is fairly short, for perfectly good mass-market machine-processing reasons, so would it be possible to dilute the developer in order that the relative differences in 'effective-developer-time' are reduced throughout the depth of the emulsion? Of course, total time would need to be extended and possibly a colour-shift would need to be CC'd. I wonder if that dilution/time idea for contrast-control might also play along with the pre-flash ideas discussed here some months ago . . .

I don't do my own C41 processing at the moment, but this might change.

 

[markbarendt]

This explanation using the depths of the layers in the film is interesting. The development time for C41 is fairly short, for perfectly good mass-market machine-processing reasons, so would it be possible to dilute the developer in order that the relative differences in 'effective-developer-time' are reduced throughout the depth of the emulsion? Of course, total time would need to be extended and possibly a colour-shift would need to be CC'd. I wonder if that dilution/time idea for contrast-control might also play along with the pre-flash ideas discussed here some months ago . . .

I don't do my own C41 processing at the moment, but this might change.

The C-41 process works correctly only when the processing standard for developing is used.

As one strays away from that standard the ability to fix color shifts with filters with the color head goes away too.

At the standard, all three film curves align in a parallel manner and in this state camera exposure has a lot of latitude where color shifts can be fixed across the whole range of exposure. When development strays away from standard the three curves stray away from parallel, when that happens you may be able to correct shifts for the mid tones but the shadows and highlights would be un-fixable and if there was a 1/2 stop difference in exposure between two frames those frames would would require different corrections.

 

[Alan Klein]

OK thanks. I guess its for BW film.

 

[georgegrosu]

Kodak present the varies of color negative films for the time and temperature variation.
http://motion.kodak.com/motion/uploadedFiles/h24_08.pdf
Depending on the brand the color negative film may be some differences compared with data from Kodak.
Is it right what he said Gerald C. Koch item 3.
This explains why the gray scale will look different to over- or under development (light gray - gray medium - black).
If you look at "Effects of Mechanical & Chemical Variations in Process ECN-2" the most important shift occurs in contamination CD2 / CD3.
A you could try a negative processing in positive color developer (CD 2).
http://motion.kodak.com/motion/uploadedFiles/h2409a(1).pdf
It is a cross proccesing.
The colors seem a bit unnatural even more contrast.
For the reversible process color (made by me) I have a solution to decrease the contrast.
The development b/w I do at ~ 26 ° C and the film go alternate developer - water (unstirred) several times .
Highlights are shown much better.
After my taste.
All are trying tests.

George

 

[Xmas]

C41 is passable x2 or /2 ISO.
Soften with large reflector or flash.
E6 stay better then 1/3 stop
Ditto for soften.

Move location to better one if you can.

If the bride is black and her dress is white sweat, incident dome on nose whatever.

 

[M Carter]

I have little experience with C41, lots with E6.

For commercial work, I rarely ran film straight - usually a 1/3 or 1/2 push. This always seemed to pop the contrast a hair and brighten teeth and eyes subtly.

When pushed a stop or more, you'll start to really close up your shadows, which can look dramatic, or bad. We would always have the lab run snip tests - 8" or so of the head or tail, and judge the rest of the roll from those.

BUT - this was shooting in controlled situations, studio or location with scrims, flags, reflectors. So usually not dealing with harsh light. And you needed to do tests to see how a given film reacted since color accuracy was key in most gigs other than pure editorial stuff.

I really, really got into pushing Kodak's 320T film (EPJ, Tungsten) two to three stops (I often shot it at 1600 or higher) and then duping those 35mm slides onto Velvia with an enlarger and a flash head taped into the condenser box (DIY daylight enlarger). Amazing color saturation and pastel-like grain - shadows could be controlled with fill light.