Exposure in film photography
Sept 17, 2017 3:02:52 GMT
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Post by Flynn on Sept 17, 2017 3:02:52 GMT
Thanks to everyone who responded. I sincerely appreciate your attention to my question. I was a little surprised at the answer, but I guess it makes sense. I didn't expect exposure in moving film photography to be so similar to still photography. Here's what I understand so far.
Film speed is set. Whatever ASA film speed that is in the camera isn't changing with a sudden change of light (barring a cut to different film stock).
In moving film, shutter speed is also set at 24 fps.
With both of those set, aperture is the only element of the exposure triangle that can respond to change. So, I guess if someone turns on a light in a room, the aperture would have to be manually adjusted to compensate. I would think depth-of-field would also change in such situations, but I guess it's very subtle. Maybe two stops of light wouldn't change DOF that much, a few feet, maybe, depending on the point of focus.
I'm guessing that there's something I'm not thinking of as well, like maybe that motion film cameras are bigger and thus let in more light than a little 35mm still film camera.
This whole question actually got me to thinking about how slow 24 fps actually is. It's not easy to take a still picture at that speed without a tripod, and so it makes me wonder how handheld movie cameras work without getting a lot of camera shake. Probably has to do with the lenses, I guess.
In any case, if there's anything anyone wants to chime in about, please feel free to do so. Otherwise, I'd like to thank everyone for the interest.
Film speed is set. Whatever ASA film speed that is in the camera isn't changing with a sudden change of light (barring a cut to different film stock).
In moving film, shutter speed is also set at 24 fps.
With both of those set, aperture is the only element of the exposure triangle that can respond to change. So, I guess if someone turns on a light in a room, the aperture would have to be manually adjusted to compensate. I would think depth-of-field would also change in such situations, but I guess it's very subtle. Maybe two stops of light wouldn't change DOF that much, a few feet, maybe, depending on the point of focus.
I'm guessing that there's something I'm not thinking of as well, like maybe that motion film cameras are bigger and thus let in more light than a little 35mm still film camera.
This whole question actually got me to thinking about how slow 24 fps actually is. It's not easy to take a still picture at that speed without a tripod, and so it makes me wonder how handheld movie cameras work without getting a lot of camera shake. Probably has to do with the lenses, I guess.
In any case, if there's anything anyone wants to chime in about, please feel free to do so. Otherwise, I'd like to thank everyone for the interest.