Video: 'Why We Still Love Film' by NBC

Discussion in 'Film and Processing' started by Karim Ghantous, Jan 11, 2020.

  1. Flare would tend to limit the low end of the characteristic curve, with relatively little effect on the dynamic range. Most of the dynamic range of B&W film is in the upper reaches of density. That said, it is the abscissa, exposure, not the ordinate, density, which is a measure of dynamic range.

    Published curves for Tri-X start near zero and stop at a density of about 3.0, at an exposure range of 3.5 log(lux-s), the latter corresponding to a dynamic capture range of 12 stops. At that point, the response is almost linear, which means the shoulder of the curve is unknown. When completely fogged, Tri-X reaches a density of at least 5.0, which represents 17 stops off the film. In order to have a capture range of 18 stops, you would need an exposure range of 6 log(lux-s), which is not unreasonable, if not actually practical. Processing which reduces the slope (gamma) is practical, however, and would have a profound effect on dynamic range.
     
  2. I learned about processing various b&w films when large DR is needed from a workshop with Bruce Barnbaum. He spoke at length on the topic when we discussed how he captured a range of 15-16 stops when photographing in Antelope Canyon back in the 80's and 90's. Issues where how to meter and expose the film...and then process to capture the range. One is definitely not limited by lens flare, etc in this regard. His work, experience, and final output where proof of that.
     
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  3. Getting it on film is one thing. Putting the results on paper, which has a dynamic range of 6 stops or so, is an art.
     
  4. Or more so a craft (which shouldn’t be underrated). Art is doing it with some sort of passion and/or expressiveness, one or two stops beyond dynamic range. :)
     
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  5. This does not agree at all with my experience and I have been passionate about the whole process for over fifteen years. I see the respective characteristics, as previously mentioned, as do other experienced people I've associated with.
     
    Dave Luttmann likes this.
  6. Wow, when trying to correct that spelling mistake, I get this: "Your content cannot be submitted. This is likely because your content is spam-like or contains inappropriate elements. Please change your content or try again later. If you still have problems, please contact an administrator". "Interesting" place.
     
  7. Kodak's pro films have more than 12 stops of DR. Most of those are in the highlight range, but still, we're talking about more than 12.

    I see nothing wrong with scanning film. I do have a problem with people who sell art prints made from negatives but printed digitally. That is unacceptable to me.
    You read into my statement something which was not there. I said that one day, digital could be a superior medium. That does not entail that digital is inferior. As you ought to know, film and digital have advantages over each other. Digital is catching up, though, and it will be interesting to see what happens.
     
    Dave Luttmann likes this.
  8. Dave, fyi here's something I've posted here a couple of times. It was published in the Kodak "Tech Bits" publication back when T-max films were relatively new.

    [​IMG]
     
  9. <continued (I wasn't actually ready to post)>

    Last time I posted this here's one of the responses:
    Apparently he doesn't know what it is, and presumably others don't either, so here's some preemptive info: first an example cover, posted on an RIT address:
    [​IMG]

    I had never heard of it until it started showing up in my work mailbox, and have no idea how I got on the mailing list, but presumably it was due to someone at Kodak. It's (was?) slanted towards industry, not the general public, and always had interesting technical articles.

    Anyway, this particular article was by Gordon Brown, a member of some Kodak scientific staff. (I listed the issue number in the image of the curves; as a note the lab work was credited to Silvia Zawadzki, a name that ought to be known to fans of Xtol developer. )Here's how he started out:

    I take it that the graph is self-explanatory to the people who are interested in it. But in a nutshell it shows that the film/developer combination can give a luminance recording range of 20 f-stops, that is, a million to one. Being a sensitometric test, the film really has this.
     
    Last edited: Jan 14, 2020
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  10. The Gordon Brown article is clear that this extreme luminance-recording range (aka dynamic range) is not really useful in general photography; rather that there are a limited number of special purpose uses.

    Note that other Tech Bits issues had articles by astronomer David Malin [sp?] regarding masking methods that he had pioneered in astronomy. Many of his well-known astronomical images had wide dynamic ranges, not suitable for normal printing. But with a broad unsharp mask all sorts of otherwise unseen detail comes out. (Look for Malin's before and after examples, if there are still any left on the internet.) The same general techniques would seem to be useful in any negative with an extreme density range.
     
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  11. Thanks Bill. That goes along with how Bruce Barnbaum worked with the films as well. Pretty obvious film excels in this regard in a way no current DSLR can. Not sure why this becomes such a contentious topic when the evidence has been around for decades and many of us actually do it.
     
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