I'm sure most of you have heard of the "bucket" analogy when it
comes to exposing film correctly (i.e., size of hose = apature, how
long the hose is on = shutter.)
Question: Where / how does film speed sensitivity fit into this?
I guess you mean bucket "diameter" (as someone else suggested).
(Larger "volume" could be established by a "taller" bucket instead.
A taller bucket gives you what -- more dynamic range?)
Maybe buckets can also explain coarse grain on highly sensitive film:
the bigger grains come from the big wide buckets. lol
Since we're talking about film (not digital sensor photosites), think of
just one single bucket (e.g. a 24x36mm rectangular bucket).
The bucket contains a "sponge". The sponge absorbs "rain" (light).
The more-sensitive film contains a more-absorbent sponge.
(A film with greater DR contains a thicker sponge.)
With color film, you've got a multi-layered sponge.
The layers react in different ways to different-colored raindrops. lol
(Of
course raindrops come in different colors, silly!
Where do you think rainbows come from?)
The water evaporates, yet the sponge retains the changes caused
by its absorption of water, i.e., your picture is now represented
within the sponge.
Then you dip the sponge in some magic chemicals, which make the
picture (negative) appear upon the surface of the sponge.
OK OK, this analogy doesn't make complete sense.
Neither do "buckets". Water is water and rain is rain.
Light is light. They're not the same. They don't really
behave the same. Films are not buckets. Films are films.
Cameras are cameras, not rain-gauges.
Analogies can be illustrative, but only up to a point.
Skip the analogies ... just talk about film! Tell me how film really works!
On second thought, don't. I flunked Chem 1A and just about
everything else. ... Besides, this is a digital photography site,
so perhaps our discussion of bucket-film belongs elsewhere.
-- omr
