inane prattle

Started Apr 8, 2013 | Discussions thread
Paul De Bra
Paul De Bra Forum Pro • Posts: 12,527
That statement is wrong for a different reason...

It is true that sensors have become better and IBIS is very good as well. But there is another reason for still wanting faster lenses:

- Typically a lens is at its best when stopped down at least 1 stop but in most cases 2 stops.

- With the smaller m43 sensor (relative to 35mm) diffraction sets in earlier. The optimal f-stop for m43 seems to be f/4, with f/5.6 still quite usable but f/8 starting to show diffraction.

These two factors combined mean that unless a lens is already at its best wide open you need at least an f/2.8 lens (1 stop down means f/4 and 2 stops down means f/5.6 so that just does it) and that f/2 is actually a safer bet (with 2 stops down reaching the optimal f/4 stop).

So the only really valid argument that says we don't need faster lenses (except for shallow DoF) would say that we don't need lenses faster than f/2.

If you would translate this story to APS-C it would say that f/4 lenses are acceptable and f/2.8 is better, and for 35mm f/5.6 is acceptable and f/4 is better.

-- hide signature --

Slowly learning to use the Olympus OM-D E-M5.
Public pictures at

 Paul De Bra's gear list:Paul De Bra's gear list
Fujifilm FinePix F200EXR Olympus OM-D E-M5 Olympus E-M5 II Panasonic Lumix G 20mm F1.7 ASPH Olympus M.Zuiko Digital 45mm F1.8 +3 more
Post (hide subjects) Posted by
(unknown member)
Keyboard shortcuts:
FForum PPrevious NNext WNext unread UUpvote SSubscribe RReply QQuote BBookmark MMy threads
Color scheme? Blue / Yellow