Seafood Carry-Out
Used the ef300 F4L IS USM with the X2 III extender on the 5D3, found that AF with the extender is *glacially* slow, completely useless for trying to catch smaller flighty birds but big slow ones like this - it's (almost) adequate. Keeper rate is truly dismal regardless of lens used.
The combination of frequent image degradation on my L tele primes + AF braking *massively* restricts the usability of the x2 III extender.
Seafood Carry-Out
Used the ef300 F4L IS USM with the X2 III extender on the 5D3, found that AF with the extender is *glacially* slow, completely useless for trying to catch smaller flighty birds but big slow ones like this - it's (almost) adequate. Keeper rate is truly dismal regardless of lens used.
The combination of frequent image degradation on my L tele primes + AF braking *massively* restricts the usability of the x2 III extender.