Ben,
It means it has a wider (widest possible) aperture which allows more light
through the lens. For a given exposure requirement, this means you can use
a shorter (faster) shutter speed.
I believe it's a vestige of the early view cameras in the 19th Century when
you really didn't have shutters. The glass plate emulsions were so slow
that one would use a lens cap for a shutter, uncovering the lens for a
number of seconds (or even minutes), and then covering it again. Thus a
"faster" lens meant the exposure occurred faster with the lens wide
open. Lower f-number means wider aperture means lens is faster. Aperture
diaphragms didn't exist then either. One would insert a plate with a round
hole in it . . . called a Waterhouse Stop . . . into the lens to stop it
down. The photographer would measure the diameter of the hole and divide
it by the length of the lens to get the f-stop number!
-- John
At 10:01 2/1/01, Ben Ashton wrote:
im new to photography and have started out on an om10. Can you tell me what
you mean when you say the lens is faster. Cheers,
Ben Ashton
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