alt Hacker News> It seems like a mistake to lump HDR capture, HDR formats and HDR display together, these are very different things.
These are all related things. When you talk about color, you can be talking about color cameras, color image formats, and color screens, but the concept of color transcends the implementation.
> The claim that Ansel Adams used HDR is super likely to cause confusion, and isn’t particularly accurate.
The post never said Adams used HDR. I very carefully chose the words, "capturing dramatic, high dynamic range scenes."
> Previously when you took a photo, if you over-exposed it or under-exposed it, you were stuck with what you got. Capturing HDR gives the photographer one degree of extra freedom, allowing them to adjust exposure after the fact.
This is just factually wrong. Film negatives have 12-stops of useful dynamic range, while photo paper has 8 stops at best. That gave photographers exposure latitude during the print process.
> Ansel Adams wasn’t using HDR in the same sense we’re talking about, he was just really good at capturing the right exposure for his medium without needing to adjust it later.
There's a photo of Ansel Adams in the article, dodging and burning a print. How would you describe that if not adjusting the exposure?
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I agree capture, format and display are closely related. But HDR capture and processing specifically developed outside of HDR display devices, and use of HDR displays changes how HDR images are used compared to LDR displays.
> The post never said Adams used HDR. I very carefully chose the words
Hey I’m sorry for criticizing, but I honestly feel like you’re being slightly misleading here. The sentence “What if I told you that analog photographers captured HDR as far back as 1857?” is explicitly claiming that analog photographers use “HDR” capture, and the Ansel Adams sentence that follows appears to be merely a specific example of your claim. The result of the juxtaposition is that the article did in fact claim Adams used HDR, even if you didn’t quite intend to.
I think you’re either misunderstanding me a little, or maybe unaware of some of the context of HDR and its development as a term of art in the computer graphics community. Film’s 12 stops is not really “high” range by HDR standards, and a little exposure latitude isn’t where “HDR” came from. The more important part of HDR was the intent to push toward absolute physical units like luminance. That doesn’t just enable deferred exposure, it enables physical and perceptual processing in ways that aren’t possible with film. It enables calibrated integration with CG simulation that isn’t possible with film. And it enables a much wider rage of exposure push/pull than you can do when going from 12 stops to 8. And of course non-destructive digital deferred exposure at display time is quite different from a print exposure.
Perhaps it’s useful to reflect on the fact that HDR has a counterpart called LDR that’s referring to 8 bits/channel RGB. With analog photography, there is no LDR, thus zero reason to invent the notion of a ‘higher’ range. Higher than what? High relative to what? Analog cameras have exposure control and thus can capture any range you want. There is no ‘high’ range in analog photos, there’s just range. HDR was invented to push against and evolve beyond the de-facto digital practices of the 70s-90s, it is not a statement about what range can be captured by a camera.
> Film negatives have 12-stops of useful dynamic range
No, that’s not inherently true. AA used 12 zones, that doesn’t mean every negative stock has 12 stops of latitude. Stocks are different, you need to look at the curves.
But yes most modern negatives are very forgiving. FP4 for example has barely any shoulder at all iirc.