vicmortelmans
Well-known
I was contemplating the zone system again and I was wondering how many zones are covered by reflective capacity of object (thus: excluding shadow effect) and how many by shadow effect.
I did the experiment and took two sheets of colored paper: one white and one black, and positioned them in identical light conditions. (Spot-)metering the white paper gives a read-out that is ~4 stops higher than the black paper.
Also consider the fact that some object in direct sunlight is ~3 stops brighter than the same object in shadow (or back-lit) (sunny 16 vs. shady 5.6).
If you add the two, one can see that a scene containing objects with black and white surfaces, that are partly lit by sunlight and partly in shadow, spans a range of 7 stops in total, from a black surface in shadow to a white surface directly lit.
Adam's zone system provides room for 11 zones: 0-X. Zones 0 and X are just collectors for everything that's out of range (no detail), and zones I and IX is for the first faint discernable detail. Leaving zones II to VIII for the actual image information... hey, that's 7 zones in total! Seems to match perfectly to the number of stops the a scene will typically span!
Groeten,
Vic
I did the experiment and took two sheets of colored paper: one white and one black, and positioned them in identical light conditions. (Spot-)metering the white paper gives a read-out that is ~4 stops higher than the black paper.
Also consider the fact that some object in direct sunlight is ~3 stops brighter than the same object in shadow (or back-lit) (sunny 16 vs. shady 5.6).
If you add the two, one can see that a scene containing objects with black and white surfaces, that are partly lit by sunlight and partly in shadow, spans a range of 7 stops in total, from a black surface in shadow to a white surface directly lit.
Adam's zone system provides room for 11 zones: 0-X. Zones 0 and X are just collectors for everything that's out of range (no detail), and zones I and IX is for the first faint discernable detail. Leaving zones II to VIII for the actual image information... hey, that's 7 zones in total! Seems to match perfectly to the number of stops the a scene will typically span!
Groeten,
Vic
vicmortelmans
Well-known
I only considered outdoor lighting by the sun.
If you consider indoor conditions, things are different.
Objects lit by a single light bulb loose 2 stops in brightness, when the distance from the bulb is doubled. So take e.g. two objects in a room, one at 25cm from the light source and one at 2m from the light source, the first will be 6 (!) stops brighter than the latter. If the objects themselves have a contrasty texture of 4 stops, this scene will span 9 zones and will be hard to catch for normal film. This doesn't even take into account shadow effect, as shadows from a single light source are pitch dark and will stretch far beyond the 3 stops of 'sunny shadow'.
Similar when using flash: the object at 1m from the camera will be 2 stops brighter than the object at 2m from the camera. But in this case, the shadow effect is eliminated, as all shadows fall behind the subject.
Groeten,
Vic
If you consider indoor conditions, things are different.
Objects lit by a single light bulb loose 2 stops in brightness, when the distance from the bulb is doubled. So take e.g. two objects in a room, one at 25cm from the light source and one at 2m from the light source, the first will be 6 (!) stops brighter than the latter. If the objects themselves have a contrasty texture of 4 stops, this scene will span 9 zones and will be hard to catch for normal film. This doesn't even take into account shadow effect, as shadows from a single light source are pitch dark and will stretch far beyond the 3 stops of 'sunny shadow'.
Similar when using flash: the object at 1m from the camera will be 2 stops brighter than the object at 2m from the camera. But in this case, the shadow effect is eliminated, as all shadows fall behind the subject.
Groeten,
Vic
vicmortelmans
Well-known
and of course, even outdoors, you can have deeper shadows than 3 stops, e.g. under a dense tree or a shelter.