Comment by dahart
2 days ago
Literally the sentence preceding the one you quoted is “What if I told you that analog photographers captured HDR as far back as 1857?”.
2 days ago
Literally the sentence preceding the one you quoted is “What if I told you that analog photographers captured HDR as far back as 1857?”.
And that quote specifically does not "lump HDR capture, HDR formats and HDR display together".
It is directly addressing capture.
Correct. I didn’t say that sentence was the source of the conflation, I said it was the source of the Ansel Adams problem. There are other parts that mix together capture, formats, and display.
Edit: and btw I am objecting to calling film capture “HDR”, I don’t think that helps define HDR nor reflects accurately on the history of the term.
That’s a strange claim because the first digital HDR capture devices were film scanners (for example the Cineon equipment used by the motion picture industry in the 1990s).
Film provided a higher dynamic range than digital sensors, and professionals wanted to capture that for image editing.
Sure, it wasn’t terribly deep HDR by today’s standards. Cineon used 10 bits per channel with the white point at coding value 685 (and a log color space). That’s still a lot more range and superwhite latitude than you got with standard 8-bpc YUV video.
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Yes, Ansel Adams was using a camera to capture a scene that had high dynamic range.
I don't see the confusion here.
HDR is not referring to the scene’s range, and it doesn’t apply to film. It’s referring superficially but specifically to a digital process that improves on 8 bits/channel RGB images. And one of the original intents behind HDR was to capture pixels in absolute physical measurements like radiance, to enable a variety of post-processing workflows that are not available to film.
"High dynamic range" is a phrase that is much older than tone mapping. I see uses of "dynamic range" going back to the 1920s and "high dynamic range" to the 1940s:
https://books.google.com/ngrams/graph?content=dynamic+range%...
You might argue that "HDR" the abbreviation refers to using tone mapping to approximate rendering high dynamic range imagery on lower dynamic range displays. But even then, the sentence in question doesn't use the abbreviation. It is specifically talking about a dynamic range that is high.
Dynamic range is a property of any signal or quantifiable input, including, say sound pressure hitting our ears or photons hitting an eyeball, film, or sensor.
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The digital process of tonemapping, aka. 'what Apple calls Smart HDR processing of SDR photos to increase perceptual dynamic range', can be applied to images of any number of channels of any bit depth — though, if you want to tonemap a HyperCard dithered black-and-white image, you'll probably have to decompile the dithering as part of creating the gradient map. Neither RGB nor 8-bit are necessary to make tonemapping a valuable step in image processing.
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