What the heck is an f-stop?

Started Apr 25, 2014 | Discussions thread
Shop cameras & lenses ▾
Allan Olesen
Senior MemberPosts: 3,357
Re: What the heck is an f-stop?
In reply to bobn2, Apr 26, 2014

bobn2 wrote:

Allan Olesen wrote:

D Cox wrote:

So the illuminance is directly proportional to the f number.

So if you change the f number with a factor of 2, you also change the illuminance with a factor of 2?

Or do you use an alternative definition of "directly proportional".

The illuminance is inversely proportional to the square of the f-number because it's proportional to the area of the aperture.

I asked a rhetorical question to D Cox.

Reply   Reply with quote   Complain
Post (hide subjects) Posted by
Keyboard shortcuts:
FForum PPrevious NNext WNext unread UUpvote SSubscribe RReply QQuote BBookmark MMy threads
Color scheme? Blue / Yellow