Litho film - not entirely monochromatic?

A long time ago there was a blog post on F295 (RIP) -- it was of a snow scene made on ortho litho film. Even though it's orthochromatic film, it produces a high contrast monochrome negative. Yet, in this one picture, the densest areas (sky and snow) had blue tones. I had my doubts since the author said it was a negative scan and that there were only minor adjustments made "in post." Even so, my own scans of my own exposures backed this up. But I couldn't say for sure whether it was the film or some phenomenon of scanning and/or digital workflow.

During the holiday break, I finally got around to making some optical prints from these negatives on to RA4 (color) paper. I made one "straight" print meaning I set the filtration to produce gray. On a couple others, I tweaked the filtration slightly off of this "center." One of these, at first glance, looks like a color print, with shades of green, yellow and blue. The others are more subtle -- the grayscale print shows some blue in the sky, but it's not profound. Still it's there.

First, how do you describe black and white film that behaves or responds in this manner (is there a word for this)? Second, how do you explain it? I'm intrigued by the possibilities but might like a better understanding of what's happening.

I've printed regular B&W film in a colour darkroom and tweaked the filters to add all sorts of colours. That doesn't mean the film has colour but it's being introduced by the colour process.

Ditto Michael W

I'm not talking about tweaking the filters to produce color; I'm talking about the film producing different colors under a single filtration. Traditional black and white film doesn't do this.

bvy said:

I'm not talking about tweaking the filters to produce color; I'm talking about the film producing different colors under a single filtration. Traditional black and white film doesn't do this.

Click to expand...

If you have different colors - this means that your RA-4 process is not correctly calibrated. If you have only one color shift - it's perhaps influence from film developer. It's possible to get different colors on traditional b/w film emulsion using only different concentration of common developing agents - metol and hq. And it doesn't matter - lith emulsion or not, but the tone color can be different for different emulsion. These techniques were widely used at the beginning of XX century - for toning diapositives during development process, which were made by contact printing on usual negative glass plates. They even sometimes can have two colors - one in shadows, another in lights, but in this case developer concentration was not enough and effect was achived by additional toning.

dE fENDER said:

If you have different colors - this means that your RA-4 process is not correctly calibrated. If you have only one color shift - it's perhaps influence from film developer. It's possible to get different colors on traditional b/w film emulsion using only different concentration of common developing agents - metol and hq. And it doesn't matter - lith emulsion or not, but the tone color can be different for different emulsion. These techniques were widely used at the beginning of XX century - for toning diapositives during development process, which were made by contact printing on usual negative glass plates. They even sometimes can have two colors - one in shadows, another in lights, but in this case developer concentration was not enough and effect was achived by additional toning.

Click to expand...

Thanks for the feedback, but I'm pretty sure my RA-4 process is fine. I've made color prints from black and white film before and not seen anything like this (I get a range of tones but of a single hue). Also, if it were my process, I wouldn't expect to see the tones show up the same way every time (using the same exposure and filtration settings). Also worth noting is that I see the same thing when I make a raw scan of the negative (i.e. all adjustments are turned off) -- the image is grayscale with blue appearing in overexposed areas (skies, snow).

Here's an example. The filtration is deliberately set toward yellow, but you'll notice greenish or cyan tones in the sky.

I think you are missing the point bvy.

Black and white films may have certain color casts because of any number of reasons like using a Pyro developer or improper washing or poor fixing or nose oil or ...

If the negative has a color cast it would produce odd results on color paper. That doesn't mean in any way shape or manner that it has carried over a color purposefully from the scene to the paper.

markbarendt said:

Black and white films may have certain color casts because of any number of reasons like using a Pyro developer or improper washing or poor fixing or nose oil or ...

If the negative has a color cast it would produce odd results on color paper. That doesn't mean in any way shape or manner that it has carried over a color purposefully from the scene to the paper.

Click to expand...

You hit a few points. I do believe the colors are in the negative, but do not believe they correspond to the colors in the scene (except maybe coincidentally). Also, the f295 post that I mentioned in my OP attributed this phenomenon to the developer. I had forgotten that point. He was using a homemade developer. I achieved the same results with Ilford PQ at 1+14. Maybe that's all it is.