Y'know, in the labs I've worked in we always spelled things out. My collaborators and I have always been as clear as possible. "x is a highly variable value" isn't very informative. "x is determined by y, z, ... " is.
I've looked at your profile, see that you say you're "a scientist." That covers many fields with different standards.
As I said, vagueness is a sin. It sometimes, but not always, reveals ignorance (see your question on extension at 1:1, posted earlier today, for an example of a question that reveals lack of knowledge) and attempts to mislead. Telling strangers about whom you know little "I'm a scientist. Shut up." is insulting. Unwise, too.
No one knows everything. Trying to fill in gaps in knowledge and understanding is good. Trying to use credentials earned in one field to gain credibility in another isn't.
Regardless of whether one is in a New-Agey frame of mind. ;-)
I think one does not need to know if the hyperfocal calculation if from the lens, or film because it does not make any difference. Say the hyperfocal distance is 65 feet. So what. No one is going to be measuring that distance. It is just an intellectual curiosity. If you were going to measure a focusing distance, one would just focus the lens.
What might be stochastic (because it is subject to a range of subjective factors) is what people interpret as appearing to be sharp. There is not some binary boundary between sharp and unsharp. A print made a bit too large might still look acceptable to most people, and some critical viewers might not accept any of the usual standards of sharpness (many of which originated in the Zeiss Formula).
And that leads to the practical truth that outside the macro range, it probably doesn't matter whether the measurement is made to the film, lens, or tripod center column for that matter. And focusing at the hyperfocal distance is always outside the macro range.
DOFMaster (with their 8x10 print assumption) claims that the hyperfocal distance for a 47mm Super Angulon on 4x5, at f/16, is 4.7 feet. A couple of inches (i.e., the distance from the film to the lens) one way or the other makes not much difference. At f/32, it's 2.4 feet--still more than an order of magnitude greater than the focal length. The hyperfocal distance they report for a 300mm lens on 8x10, at f/32, is 47 feet. The difference of a foot between the lens and the film is not significant. Stricter standards of sharpness as indicated by selecting smaller circles of confusion just make the hyperfocal distance that much greater with respect to the focal length.
Remember, the thread was about hyperfocal distance, not more generally about depth of field.
Rick "who has spent a big chunk of his career defining variability" Denney
So you don't think that it was worth mentioning the two different practices at all? I often ask myself if there is any real point in answering questions on the internet.
PS The online version of DoFmaster allows you to choose your own max. acceptable CoC if you wish.
But those who said it didn't matter were not without justification for their point of view. Saying it doesn't matter in practical application, however, isn't the same thing as saying nobody is interested in the different approaches.
Yes, as I said, I always cut the circle of confusion value used by DOFMaster in half. In the iPhone version, which I use, I select my desired C of C from the table, rather than choosing a format.
Rick "just trying to keep things in perspective" Denney
But when I make a slip at 1.45am or something you go to say it "reveals ignorance".