Help me understand f number with constant aperture zoom lenses

Started Jul 25, 2012 | Discussions thread
manmachine242
Regular MemberPosts: 386
Like?
Re: Help me understand f number with constant aperture zoom lenses
In reply to Gweedz, Jul 25, 2012

Gweedz wrote:

My understanding is at 50mm focal length, the aperture is 17.8mm diameter (50/2.8), and at 17mm focal length the aperture is 6mm dia.

No, the 17.8mm is the diameter of the entrance pupil, the projection of the aperture.

-- hide signature --
Reply   Reply with quote   Complain
Keyboard shortcuts:
FForum PPrevious NNext WNext unread UUpvote SSubscribe RReply QQuote BBookmark post MMy threads
Color scheme? Blue / Yellow