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

David_S85 wrote:

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?

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

ian408 wrote:

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.