ISO as a factor in exposure?
I don't hear anyone in apug saying so but folks in the D forum consider ISO as one factor in exposure. They talked about the exposure triangle. But however, one control the amount of exposure by changing the subject brightness (if that is possible), changing the aperture or changing the shutter speed. The ISO doesn't change the amount of exposure the film gets.
The ISO does not change how much exposure the film gets, but it changes how much exposure the film needs.
I certainly consider ISO a factor. I like very slow film for some things, as I like long exposures, with blurred crashing waves, that kind of thing.
I'd love to see a forgiving C41 film like Portra 400, but with an ISO of 25 or something, would be really interesting to use. I could get an ND filter I guess.
In one respect it is. But since the ISO is selected in advance by your choice of film it is a passive part of exposure. In a way it becomes the platform off which your other exposure decisions are based. Obviously it is more dynamic in the d***l camp.
But, if you shoot large format, you can easily use ISO just as dynamically.
It is part of the triangle. ISO or EI determine the amount of exposure as stated above. Then, given that, the other sides can be determined based on desired outcomes. Change 1, and the others must change to keep the same image properties.
In the digital world, you can adjust the light sensitivity by changing a setting on the camera.
In the film world, in some cases, we can switch film backs.
“Photography is a complex and fluid medium, and its many factors are not applied in simple sequence. Rather, the process may be likened to the art of the juggler in keeping many balls in the air at one time!”
Ansel Adams, from the introduction to The Negative - The New Ansel Adams Photography Series / Book 2
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Or just keepclicking away until the film advances no more, rewind and then load in a different ISO.
Originally Posted by MattKing
The Zone System and its kin use sort of the same point of view, in which the (effective) speed of the recording medium becomes the third variable. Where the Zone System folks say "N+1", the digital shooters are saying "increase the ISO setting", but it comes to much the same thing: a stop less exposure.
San Diego, CA, USA
The lady of the house has to be a pretty swell sort of person to put up with the annoyance of a photographer.
-The Little Technical Library, _Developing, Printing, And Enlarging_
By the way, ISO stands for American Standards Association. HNY
Anybody shot with a disposable?
Essentially what changes/adjusts with each shot in these cameras is the EI. The only way to adjust exposure with these cameras is by switching films or adjusting your print process.
I shoot this way with my Holga, drop in a roll of Portra 400 or 800, go shoot, and then adjust the enlarger to suit the frame. Works surprisingly well.
Mark Barendt, Ignacio, CO
"We do not see things the way they are. We see things the way we are." Anaïs Nin
And ASA stands for the International Standards Organization.
Or is that the other way around...