M focus with 16-55 f2.8 and back button

Just picked up the 16-55 f2.8 and took it for a spin on my XT-2.  First bunch of  shots were not sharp so I began to worry that I got a bad copy.  As I looked thru a few more shots they became nice and sharp so I determined to figure out the difference.  The only thing I had changed while out shooting was selecting S focus on the front switch - it had been on M when I started.  (Since I setup the XT-2 for back button focusing there is not really much difference.)

Long story short - the 16-55 f2.8 lens is seriously front focusing when set on M and using the AF-L button to acquire initial focus.  This is on both my XE-2 and XT-2.  I can manually focus, then press the AF-L button and can clearly see it set the focus way in front again (I use peaking to see the effect).

I tested my 14, 23 1.4, 35 1.4, 60 and 18-55 and they do not behave this way on either camera.  Since I do use M with back button sometimes,  this behavior bothers me - i am afraid I will not notice or forget when using the 16-55 and come back with out of focus shots.

Before I send this back would someone with a 16-55 f2.8 test for the front focusing behavior when in M mode using the AF-L button for initial focus?   So far this lens is great otherwise, so if this is normal I will most likely keep it - my copy of the 18-55 is not very sharp.

TIA

My 16-55 works fine with the back-button technique on an X-T2.  Happy to post a shot if you'd like me to.

Do you have the latest firmware? The first FW update for the 16-55 fixed some odd focusing behaviors.

Yes, double check the firmware version for both the camera and lens. And also be aware that on the X-T2 it is not necessary to set the camera to M to use back button focusing. There is a menu option to remove AF-ON from the shutter button so that you can back button focus in S or C mode much like with a Nikon etc dSLR.

Back home now and just did some testing and focus is spot on with back button at 55mm and f2.8, M or S mode. So yes, something off with your lens.

Thread resurrection, I realise, but I have found the same issue with an X-H1 and 16-55 f2.8.

I had been routinely using back button focusing and with the recently-acquired 16-55, was noticing inaccurate focus on a regular basis.   Eventually noticed that the focus problems seem to abate when using AF-S and Shutter AF ON.

digitaria wrote:

Thread resurrection, I realise, but I have found the same issue with an X-H1 and 16-55 f2.8.

I had been routinely using back button focusing and with the recently-acquired 16-55, was noticing inaccurate focus on a regular basis. Eventually noticed that the focus problems seem to abate when using AF-S and Shutter AF ON.

I have my rear command dial set for AF On and it focuses my 16-55 just fine in M mode (I use the shutter button otherwise) I don’t know why your 16-55 should behave differently from your other lenses in M mode.

No, it doesn't seem logical that this would happen, but symptoms are consistent with those reported upthread and it is quite reproducible, if you switch mode between shots.