AF lenses - always on?

[David_S85]

I thought this is kinda strange. The 20D is OFF and the lens is switched to AF. The focus ring is difficult to turn (no, I'm not forcing it, don't worry). Then if I switch it to MF, the focus ring turns easily.

So, am I to understand that with the camera OFF, the lens is still ON and draining the battery continuously? :scratch

I used to have a turntable that did the same thing when OFF.

[ian408]

I thought this is kinda strange. The 20D is OFF and the lens is switched to AF. The focus ring is difficult to turn (no, I'm not forcing it, don't worry). Then if I switch it to MF, the focus ring turns easily.

So, am I to understand that with the camera OFF, the lens is still ON and draining the battery continuously? :scratch

I used to have a turntable that did the same thing when OFF.

Shouldn't be on. If the camera is off, no power should be delivered to the
lens.

Ian

[David_S85]

Shouldn't be on. If the camera is off, no power should be delivered to the
lens.

Ian
That's right. No power should be directed to the ring motor with the cam OFF, but the USM motor is nevertheless giving quite a bit of resistance on it's own unless the lens is parked in MF. Hmmmm.

[ScottMcLeod]

Depends which lens.

Non-USM lenses are like glue/molasses when they're in AF and the camera is off.