R7 Refuses to Focus Until Manually Focused Close to Object

[mikwar]

I have a R7 body and am using the Canon 100-400mm EF lens with the EF-EOS-R Control Ring Mount.  I used the same lens with my Canon D7 MII for 100K shots and never had a similar focus issue.  The issue comes when the camera was focused on a distant (30 yards) object and then I try to attain focus on a closer object (10 yards).  The camera/lens will not even attempt to focus on the object and I have to manually focus close to the object, at which time the lens' autofocus kicks in.  The same occurs when changing from a near object to more distant one.  Once the camera/lens begins to Autofocus it is spot-on and the Animal Eye Detection works fine.  Additionally, when the Autofocus is working it seems to take a bit longer to attain focus than when I was using the lens on the D7.

My camera is set on Servo, One-point using back button shutter release.  I am photographing birds and I often lose a subject while trying to manually adjust the focus. 

This is not acceptable but I can't determine if this is the fault of the camera, Control-ring Mount and/or lens.

Thanks for any suggestions,

mikwar

[Waddizzle]

I do not think there is a problem with either the lens or the mount adapter.  The most likely cause is a camera setting that is preventing the CAMERA from continuing to focus. 

Try this!  Put the camera into the automatic Green [A+] shooting mode.  If the problem seems like it has gone away, then this confirms there is camera setting somewhere that is holding it back.

The most likely culprit is a setting that controls whether or not the camera will continue to hunt for focus once it has completely lost focus tracking on a subject.  You could look for it in the AF menus, or you could do a factory reset of the camera.  A factory reset to default settings should not affect your BBF custom control programming because that menu has its own reset function.

[mikwar]

Testing the camera using the A+ shooting mode was a great suggestion.  Yes, the camera was able to focus wherever I aimed - near to far, far to near.  I agree with you that the issue must be an AF setting.  Trying to figure out which one is my next task.  Thanks for the suggestion.  If anyone has an idea of which setting could be causing this I would appreciate a reply.

[Waddizzle]

I thought I provided you with information to find the needle in the haystack.  You can look through all of the AF menus for the selection that disables AF when it loses track of the subject, or allow it to keep hunting.  

[Search for the phrase “Continuous AF” in the Advanced User Guide for the camera.}

The factory default is to allow it keep hunting.  Reset the camera back to factory default settings.  We all do/did it repeatedly until we could understand the camera and remember where the settings are the we had changed to cause the camera misbehave.

[mikwar]

Thanks again for your suggestions.  Indeed you narrowed down my search considerably.

[mikwar · Accepted solution]

I determined that the problem was in an Autofocus setting.  In AF-3, "Lens drive when AF impossible" was set to OFF.  By turning it ON I am now able to point my camera at any object, near or far, and have it attain good autofocus.

[ASharma]

I have the same problem, which also resolves in A+ mode, which does seem to identify a role for some menu setting. But setting "Lens drive to AF Impossible" to ON failed to fix it.  Nor have I been able find any other setting that addresses the issue. I'd obviously be thrilled if anyone has a specific suggestion.

[ASharma]

I'm adding an alternate solution I found to the same issue.

To remind you, I was also running into this problem when the manual focus ring on the RF-S 18-150 mm lens was inadvertently turned to a “close distances” even when the R7 body AF/MF switch was set to AF. Basically, I would get stuck in MF mode i.e. the AF square would disappear, the focus distance guide would appear, and the autofocus would be disabled until I manually “zoomed out” with the manual focus ring. As note,  this was not a problem in A+ mode, which suggested a menu setting on my R7. 

Since then, I have been able to do some trouble-shooting. Firstly, I had the opportunity to test my lens on a neighbour’s R10 and an R7 bodies, and I was unable to reproduce the problem on either. In the solution above,  it was suggested it might be related to the setting of the “Lens Drive when AF Impossible” menu option, and my local camera store also suggested toggling the “Electronic full-time MF” menu option. Unfortunately, these did not remedy the issue; nor was it related to any other menu obviously referring to the manual focus ring. 

However, as I continued my trial-and-error experiments, I realized that I use back-button focus rather than the default front-button operation. As soon as I reset the function of the shutter button to both shutter and focus (“Customize Buttons”), the aberrant behaviour disappeared, with all my other customizations left untouched.

So it clearly seems to be an issue with how the manual focus ring on the RF-S 18-150 works when back-button focus is active. In any case, it doesn’t appear to be a hardware problem, and perhaps it will addressed in a future firmware update.