I read years ago that TMX had a range of at least 22 stops in the lab. This was before widespread use of scanning, so it was beyond any printing technique of the day to make use of this huge amount of data. It was just a laboratory exercise.
I'm curious however about how to measure what film actually does. The thing about film and developers is that slope of the response curve. I can manipulate that slope at will using the normal tools of developer, dilution, temperature, and time. Such that an SBR of 18 stops can be crammed into a density range on film of maybe 1.5 (I have no idea what your Dmax actually is, so I'm just using 1.5 as an example).
The question is, did I actually preserve the full separation between the stops of SBR? Or, how much separation in density do I need between the stops of SBR to record it correctly? Does it have to be a log density of 0.3? Is 0.1 enough? IDK. I never purposefully pursued answers to these questions as I don't seem to be attracted to subjects of such high SBR.
OTOH, I have done some experiments in trying to optimize my film, exposure, and development for (drum) scanning. What I found is that reduced Dmax was better for scanning. To a point. As I reduced Dmax I got to a point there I was squeezing tonal detail too much and wasn't able to fully replicate it in scanning. IOW you can shoe horn too much SBR into a restricted density range and lose some of it in the process.
Then came the printing. The restricted range of light reflecting off a paper print is the limiting factor in all this. And that depends mightily on the amount of light available to reflect off the print.
Where I'm going with this ramble is that really large SBRs get compressed mightily in the final print. In part because of the limited dynamic range of the print -- the laws of physics are the laws of physics and all that. But mostly because we want a decent looking print, which means mid-tone contrast. Which in turn means compression of the shadows and the highlights -- or clipping of some of the shadows and/or highlights. So even though we can record and process so that we preserve all the SBR of the scene on the negative, we can't necessarily show it all on the print. Or even want to show it all on the print.
But that would be where light boxes and display transparencies come in I suppose.
Still, good work. TMY-2 is my only B&W film these days. And this is partly why.
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