topic Re: Canon EF 70-200mm F/2.8L IS III USM focus problem in EF & RF Lenses

Canon EF 70-200mm F/2.8L IS III USM focus problem

ChrisPBacon — Wed, 22 Jan 2020 01:41:32 GMT

I recently upgraded my aging EF 70-200mm f/2.8L IS lens with the purchase of the newer model and have found that as I'm approaching 200mm (at f/22), all but the center portion of the photo is losing focus, though the center portion remains in focus. The lens is clean; at the same temperature (cold-soaked) as ambient; free of condensation; within the AF focus distance; the lens is properly seated and locked on the camera body. Several test shots elegantly prove it's the new lens, not the camera or other lenses).

Anyone else seeing this?

Re: Canon EF 70-200mm F/2.8L IS III USM focus problem

Tronhard — Wed, 22 Jan 2020 02:10:56 GMT

@ChrisPBacon wrote:
I recently upgraded my aging EF 70-200mm f/2.8L IS lens with the purchase of the newer model and have found that as I'm approaching 200mm (at f/22), all but the center portion of the photo is losing focus, though the center portion remains in focus. The lens is clean; at the same temperature (cold-soaked) as ambient; free of condensation; within the AF focus distance; the lens is properly seated and locked on the camera body. Several test shots elegantly prove it's the new lens, not the camera or other lenses).

Anyone else seeing this?

Never seen it but sounds like something stuck or loose in the lens. If you got it from a reputable store I suggest taking it back, along with your camera and having a chat. If it is warrantied, Canon support would be the logical alternative step.

Re: Canon EF 70-200mm F/2.8L IS III USM focus problem

Waddizzle — Wed, 22 Jan 2020 06:34:40 GMT

@ChrisPBacon wrote:
I recently upgraded my aging EF 70-200mm f/2.8L IS lens with the purchase of the newer model and have found that as I'm approaching 200mm (at f/22), all but the center portion of the photo is losing focus, though the center portion remains in focus. The lens is clean; at the same temperature (cold-soaked) as ambient; free of condensation; within the AF focus distance; the lens is properly seated and locked on the camera body. Several test shots elegantly prove it's the new lens, not the camera or other lenses).

Anyone else seeing this?

At f/22, do you say? Depending upon how far away was [your] subject, that sounds pretty normal to me. Nothing to see here.

Re: Canon EF 70-200mm F/2.8L IS III USM focus problem

Tronhard — Wed, 22 Jan 2020 06:31:30 GMT

I missed the bit about f22. Not sure why one would want to shoot at that aperture, bit you"re going to get fairly major issues at the for many lenses.
Its sweet spot is more like f5.6-f8!

Re: Canon EF 70-200mm F/2.8L IS III USM focus problem

ChrisPBacon — Wed, 22 Jan 2020 07:17:15 GMT

@Tronhard wrote:
I missed the bit about f22. Not sure why one would want to shoot at that aperture, bit you"re going to get fairly major issues at the for many lenses.
Its sweet spot is more like f5.6-f8!

For this particular subject, I wanted a clear, sharp background which told the story about the individual. I did a number of test shots at lower aperture numbers and found many examples of objects on the same (distance) plane out of focus.

My partner tried the lens on their camera with the same results.

Fortunately, I purchased the camera new from a reputable store and will return it next week when I'm in the area with prints to demonstrate my concern.

Re: Canon EF 70-200mm F/2.8L IS III USM focus problem

ebiggs1 — Wed, 22 Jan 2020 16:16:43 GMT

This was a used lens? Return it.

You know f22 may not deliver the sharpest photos. Lens aperture diffraction is an issue as the aperture gets very small like f22.