Thursday, January 23, 2020

Working in Black and White ~ further refinements

While visiting the Charles Negre photography museum here in Nice, France, I was able to closely inspect various black and white images.  I was paying particular attention to the grain structure as it varies with print tones (a topic for a future post, perhaps?) and how the whites are rendered under various circumstances.

In an earlier post I suggested a conversion process from digital color into black and white that involved rising the mid-tones to match silver halide black and white printing.

Recently I suggested a Rawtherapee filter that helps separate subtle colors in a way that could be pleasing to the eye.  It's worth noting that black and white filters vary from software package to software package.  I feel it's worth testing whichever software package is used (ie: Lightroom, Photoshop, Darktable, the Gimp, etc) for oneself to find the filter that gives the most pleasing effect.

In this post I would like to illustrate the overall effects of these two steps as they relate to the gray scale.  I would also like to suggest a way to "manage" the creaminess of the highlights so that they very closely match those of film printed to black and white paper.

The base for this post is a simple gray scale step wedge (top image). 

By rising the center of the "curve" it is easy to see how the mid-tones rise and how the steps between the shades of gray on the white end of the scale "flatten out" (center image).

After returning home from the Charles Negre museum I considered how a digital file can be converted to black and white and nearly perfectly match how silver halide film/print combinations behave, specifically in the highlights.  I think I have a suitable answer.

After applying a yellow-green filter and after rising the mid-tones by rising the center of the image "curve" the effect of "creaminess" in the highlights can be enhanced by lowering the "brightness."  This "narrows" the gaps between the various shades of white and lowers the absolute/pure white so that it begins to take on a pale gray tone.

The following might illustrate what I mean.

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