The alternative to the ultra-fast long telephoto?
In article , Alfred
Molon wrote:
Specifically, when Autofocus capability is disabled when a certain
f/stop value is exceeded.
Why?
because it no longer works properly, or is too slow to be useful.
If memory serves, the common "upper limit"
value had been f/5.6, with some exceptions at f/8 (such as offered
only on higher end bodies, and/or only at the center focus point).
I have the Olympus 75-300 which is F6.7 at the tele end, but autofocus
works also at the tele end.
not very well, it doesn't.
|