EF500L Autofocus

[Frank Kolwicz]

It's a good thing I'm patient.

Because I'm still not satisfied that the EF500L lens is AF-ing properly: with the camera on a tripod, focussed on a distant stationary subject, using a remote release so that nothing is moving, every time I trigger AF I can hear the lens AF moving and see that the confirmation light goes from off to on. That is, it seems to re-focus on the same thing each time, but also seems to lose that focus each time after releasing the shutter or taking my finger off without releasing.

My EF100-300L does not do this, there is no sound of re-focus (and it's much noisier than the 500) only the confirmation light comes on, so it seems to have locked focus on the subject, unlike the 500.

I'm still seeing a lot of images that have focus behind the subject using center point AF only with subjects big enough to fill that area, despite having re-run the AF microadjustment 4 or 5 times.

Is this normal?

[Bob Atkins]

Are you in one shot AF mode?

I can tell you that in one shot mode on a close target (6m), my EF500/4.5L on an EOS 7D doesn't refocus for each shot. I have seen some EF lenses that do that though. If I remember right I think my 50/1.8 does, but it's so noisy you can't miss it! You can check if the 500 is refocusing by watching the distance scale. If you see it twitch, then it's refocusing.