• Removed user
    June 1, 2023, 5:44 p.m.

    I am curious as to why or when the order of e.g. "100 ASA" got reversed to "ISO 100".

    Being a stubborn old git, I always write the exposure index number followed by a space then "ISO" ...

    OT, but I always write f/4 as opposed to referencing a Douglas Phantom jet airplane ...

  • edit

    Thread title has been changed from "ISO 100" versus "100 ASA".

  • Members 300 posts
    June 1, 2023, 6:02 p.m.

    Something I also have been thinking. The ISO sign came in film roll packs in 1990 tale as an alternative of ASA. I still wonder the definitions of ISO and ASA are different.
    And I wonder the definition(s) of ISO was also reason to much the confusion about "exposure" or "exposure triangle" in beginners discussions.
    If somebody knows, answer please!

  • Members 1737 posts
    June 1, 2023, 6:11 p.m.

    I can’t see that it makes any difference which comes first. There seems to be no confusion as to the meaning.

  • Members 83 posts
    June 1, 2023, 6:13 p.m.

    en.wikipedia.org/wiki/Film_speed

  • Removed user
    June 1, 2023, 10:41 p.m.

    Obviously everyone knows what it means but that is not my concern.

    OT but, along similar lines, it bothers me when someone who shall be nameless writes "a74" instead of "alpha 7 Mk. IV" ...
    ... or when someone elsewhere writes "SDQ-h", not "sd Quattro H" .. I could go on but Danno is probably circling ... :-)

  • Members 1737 posts
    June 1, 2023, 11:11 p.m.

    You say po-tay-to, and I say po-tah-to.

    www.youtube.com/watch?v=LOILZ_D3aRg

  • Members 511 posts
    June 2, 2023, 12:38 a.m.

    I’m an ASA man, till the day I die.

    K1.jpg

    K2.jpg

    K2.jpg

    JPG, 54.9 KB, uploaded by Greg on June 2, 2023.

    K1.jpg

    JPG, 43.0 KB, uploaded by Greg on June 2, 2023.

  • Members 1737 posts
    June 2, 2023, 12:43 a.m.

    Hope you've been keeping that in your freezer all this time...

  • Removed user
    June 2, 2023, 12:57 a.m.

    I was referring to common usage in the literature.

    I remain curious as to why or when the order of e.g. "100 ASA" got reversed to "ISO 100".

  • Members 1737 posts
    June 2, 2023, 1:05 a.m.

    Note that on the Kodachrome II box it's ASA 25, not 25 ASA. The DIN index is the other way around.

  • Removed user
    June 2, 2023, 1:12 a.m.

    missed that ... thank you!

  • Removed user
    June 2, 2023, 1:15 a.m.

    Cool ...

  • Members 408 posts
    June 2, 2023, 2:09 a.m.

    Hi,

    It's probably due to the way things are said in French vs English. Such as UTC for time when we say UCT....

    Stan

  • Members 535 posts
    June 2, 2023, 11:57 a.m.

    My (faded) memories are of making and hearing references to “ASA 100”. I don’t remember the reverse being a thing — but maybe this was only true of the crowd I ran with.

  • June 2, 2023, 12:30 p.m.

    The ISO standard (12232) mandates that 'ISO' should come first when reporting ISO values. I'm guessing that the order changed when it changed from specifying which of several national standards was being used to an international one under the jurisdiction of ISO. ISO likes to promote itself, so it comes first in all ISO standards.
    So syntactically, the suffix 'ASA' was there to clarify which standard you were talking about. whilst the prefix 'ISO' is there to tell you that it's the real, international thing.

  • June 2, 2023, 12:32 p.m.

    AKA someone who shall be shameless

  • Members 408 posts
    June 2, 2023, 4:34 p.m.

    Hi,

    Ah, yes. Of course the ISO says thou shalt put our name first. :P

    And that, right there, explains it all. ;)

    Stan

  • Members 320 posts
    June 2, 2023, 4:40 p.m.
  • Removed user
    June 2, 2023, 5:44 p.m.

    Stan, the French is TUC fr.wikipedia.org/wiki/Temps_universel_coordonn%C3%A9 ,,,

    ... not popular in England because of the infamous TUC (Trades Unions Congress) - well, not popular with the Tories anyhow.

  • Members 408 posts
    June 2, 2023, 6:16 p.m.

    Hi,

    Might be why it's Universal Time Coordinated. Even the French time signal stations (for the radio frequency calibration standards) says UTC.

    The US ones say Universal Coordinated Time.

    We used to call it GMT, Greenwich Mean Time. But then I'm old! :P

    Stan

  • Members 46 posts
    June 11, 2023, 8:26 p.m.

    The Why is trivially simple: Two different standards organizations wrote the standards. The When was detailed above in the Wikipedia quotation.

  • Members 38 posts
    June 14, 2023, 1:08 a.m.

    The question was more obout the order it is written, as in 100 ASA vs ASA 100.
    I think that the manufacturers always used "ASA 100/ISO 100" but the public often preferred the 100 ASA/ISO version.
    The earliest I can find printed on a film box has that ASA first version and was like that since.
    But I cannot think of many customers saying "I'll have an ASA 100 film" as opposed to "I'll have a 100 ASA film"

  • Members 599 posts
    July 1, 2023, 5:39 p.m.

    Unless they meant "I'll have an ASA 100 film ASAP"