L Series lens question

[forrest64]

One of the things I really like about my 17-40 L is that I can turn the manual focus ring even when the lenses' switch is in the AF position. This allows me to use the camera's AF and then manually fine tune if necessary. Is this feature available on all L lenses?

[Olegis]

It's the feature available in all lenses that have USM (UltraSonic Motor).

[MarkH]

It's the feature available in all lenses that have USM (UltraSonic Motor).

My 75-300 USM lacks this feature. This is something that the micro USM lacks, but either all or most lenses with the Ring USM have it.

Canon call the feature full time manual focus, since the L range are all top lenses, they tend to feature ring type USM and full time manual focus.

[Haifidelity]

My Canon 50mm f/1.4 USM (non 'L') features micro-usm and supports full time manual focus. I suppose your 75-300 might be an older iteration of the micro-usm.

to echo everybody else here: Ring-USM, modern Micro-USM, no matter which canon lens line, supports FT-M focus.

-hza