Are 35mm legacy lenses 'slower' on m4/3?

Started Sep 22, 2009 | Discussions thread
ForumParentFirstPreviousNextNext unread
Flat view
MYKC
New MemberPosts: 8
Like?
Are 35mm legacy lenses 'slower' on m4/3?
Sep 22, 2009

One of the attractions of the m4/3 format is the possibility of using a wide range of older lenses originally designed for 35mm film cameras. This forum contains many examples of the impressive results obtained using such lenses, and users often refer to advantages of using 'fast' old lenses which have an effective focal length of double the 35mm equivalent because of the 'crop factor' of the smaller m4/3 sensor. My question is this: if most of the light gathered by legacy lenses is wasted because the sensor only occupies a fraction of the image circle, is the lens not 'slower' than the f-number suggests? In other words, the actual focal length of the lens is the same, but the effective diameter is smaller, so the effective f number is larger. IF my analysis is correct, the legacy lenses are not quite such good bargains. I can't get my head around this issue, and would appreciate any thoughts from the experts on the forum. Cheers,
Mike.

ForumParentFirstPreviousNextNext unread
Flat view
Post (hide subjects)Posted by
No.New
ForumParentFirstPreviousNextNext unread
Keyboard shortcuts:
FForum PPrevious NNext WNext unread UUpvote SSubscribe RReply QQuote BBookmark post MMy threads
Color scheme? Blue / Yellow