77D Shifting Autofocus Point during Self-Timer

[Predetc]

Hi,

I was trying to do some autofocus tests on my new lenses (using a single center focus point).  I used a tripod and the 2- and 10-second self-timers to reduce camera shake.  While watching through the viewfinder, I noticed that the camera/center focus point would move to the right while the self-timer was going. Then, after the shot was taken, would move back to close to the original focus point.  Checking in the Canon software, the focus point of the image was definitely off of where I had focused for each shot.  It happened with both of my (zoom) lenses.

Any thoughts on this?

[Waddizzle]

We need a little more information.  What is your AF mode?  Are you using One Shote AF mode, or AI Servo AF mode?  Is your subject still, or is there something moving within the viewfinder?  

If does not sound like you may not have locked focus and exposure before starting the shutter delay timer. One Shot Mode does this automatically.

When you are in AI Servo mode, it is possible to select the center AF point as a starting point, and have the focus point automatically track your subject depending upon your AF Point Selection mode.  Please refer to the page out of the User Manual below. 

This shows how to select the center AF point, while still having all AF points active for AF tracking.  The AF tracking in the latest Canon DSLRs is very good.  

Again, if you are using a tripod and the shutter delay timer, you want to use One Shot AF mode because this mode locks both focus and exposure at the moment you first half press the shutter.

[Predetc]

Thank you for your response.  I realized I need to clarify.  

The camera is on a tripod indoors focused on a stationary object (the graphic on a box or a ruler) using Manual Selection: 1 Pt AF

I tried with both AI Servo and One-Shot AF.

Also, I realized it is not simply the autofocus point that is moving.  It is the entire optic/frame of view.  

I also just tried it again and observed that the shift in view (up and to the right) occurs even without Self-Timer.  When I half press the button to obtain focus, the entire view shifts slightly up and to the right.  After I release the button, the view moves back to the orginal starting point.   If done with Self-Timer, the view moves when the button is pressed, then returns after the shot is taken.

[Waddizzle]

Okay, that is weird.  Are you using a Canon lens?  Sounds like their may be an Image Stabilization issue.

Just a note, ""Manual Selection: 1 Pt AF" is a mode typically associated with Live View, not the viewfinder AF system.

[Waddizzle]

---

@Waddizzle wrote:

Okay, that is weird.  Are you using a Canon lens?  Sounds like their may be an Image Stabilization issue.

Just a note, ""Manual Selection: 1 Pt AF" is a mode typically associated with Live View, not the viewfinder AF system.

---

If you have Image Stabilization turned on, then turn it off.  You do not need it when you are on a tripod.

[Predetc]

The same (view shift) happened with both a Canon 18-135 mmm and Sigma 150-600mm.

I just tried it with image stabilization turned off for the Canon lens and it seems to fix the problem.  I'll try later with the Sigma.

Is image stabilization a camera or lens issue?

Also, when using the viewfinder, what other AF mode is an option for single point focus?

Thanks for the help.

[Waddizzle]

---

@Predetc wrote:

The same (view shift) happened with both a Canon 18-135 mmm and Sigma 150-600mm.

I just tried it with image stabilization turned off for the Canon lens and it seems to fix the problem.  I'll try later with the Sigma.

Is image stabilization a camera or lens issue?

Also, when using the viewfinder, what other AF mode is an option for single point focus?

Thanks for the help.

---

Image stabilization is in the lens.  The problem is operator error.  Sorry.  Canon advises to turn off IS on your lens when you are using a tripod, probably to avoid the exact issue that you are observing.  If you are shooting a still scene, then use One Shot AF, most especially if you are using a tripod.

Be sure to observe the MFD, Minimum Focusing Distances, of your lenses.  The 150-600 has a fairly long MFD for indoors use.  The MFD should be printed on the lens barrels somewhere.  

As for what other AF modes are available when using the viewfinder, they are several modes covered in the User Manual, which can be download from the same web site page where you downloaded your Canon software.

Finally, be aware that the Viewfinder and the Live View screen use separate focusing systems. 

[Predetc]

Got it.

Thanks so much for your help!