Bill Burk
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- Feb 9, 2010
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Bill, please let me claryfy I never thought Lachlan was arguing with me, and I appreciate his posting veré and hace learned from him for years... And it was more than 20 years ago when I first taught someone the clear differences between ISO and EI... Quite simple definitions... And I'm not being pedantic... I just don' believe in ISO because It stopped being a standard, it's not a unified concept... They started saying 200 and D-76, then they all had a chat 60 years ago and decided to say 400... Then Kodak made TMax but for Xtol and other speed enhancing developers... Then Foma say Foma400 for a film closer to 100... So what's ISO? Nothing... One of a thousand posible tests in one of a thousand developers. ISO is not real... Film's not static: it's like a rubberband...
AND it requires what It requires: different amounts of exposure and development for different amounts of contrast in our scenes.
I talk about stablishing real film speed, something common ISO just don't reflect... A different thing would be if manufacturera had to say both ISO for sun and ISO for shades in D-76 for optimal G3 printing... Then I would believe in ISO. Long ago, ISO has been just marketing.
OK. I believe in ISO because it’s scientific.
The 1962 speed change is a fun story. So is flare, K, Zone System. Weston speeds and Hurter and Driffield inertia speeds.
I bought a book by Ron Callender a couple years ago, it was fun getting a post from the UK including a postcard of Ron’s personal photography... you can read his writing here... https://books.google.com/books?id=PJ8DHBay4_EC&printsec=frontcover#v=onepage&q&f=false
I am happy we moved away from “super fast”, “ultra fast” - those really we’re marketing terms.
Ah well, wait until you start rating film by the 0.3 gradient or Delta-X parameter. Then you will find the ISO was right all along. Looking just at the 0.1 speed point doesn’t always “tell the whole story”.