>> |
Anonymous
Yeah thanks, I've read guides, including the wikipedia page. Unless I misunderstood it, it says a 50mm lens and a 200mm lens will have a different area. Hence, my question. If the 200mm lens has a larger area, but the exposure is the same, what happens to the extra light the 200mm lens gathers?
And it does not seem to say anything about the physical size (diameter) of the lens (my first question).
Basically, is the amount of exposure indicated by an F number always the same, regardless of size, format, whatever? If yes, why does the diameter not matter? Or is there one F number for DSLRs, another for compacts, and yet another for miniature spy cameras, etc.
|