Canon 80D Video Stutter Small Aputure

[DoctorDR]

The autofocus feature in my 80D skips while video recording at an aperture wider than 13 (from 13-22).

Not only does the shutter skip, but the video footage skips as well. I tried to clean the pins, but it didn’t help. Is this user error or a problem with the camera?

[Tim]

DoctorDR, 

There are a few troubleshooting steps I'd like to help resolve this issue. We'll reset the camera, which should restore it to a default state. 

- Anything attached or installed in the camera — memory cards, the lens, the battery, battery grips should all be removed.

- Once the lens is off let's check it using the steps below.

a) Clean the lens contacts* to restore connection with the body.

b) Try using a different memory card. All memory cards should be properly formatted in your camera prior to use.

*Warning - Do not clean lens contacts on either a Canon lens or the camera body with an eraser! It's easy to rub off the gold plating on these contacts and end up with data communication problems! Our strong recommendation is to use a soft, clean, micro fiber cloth. Please do not use anything abrasive.

c) Try using a different Canon EF series lens. It doesn't have to be the same focal length as the one you were using.

d) If you are using a third party lens, we recommend discontinuing its use. There can sometimes be communication error related issues with third-party lenses. Ensuring that you're using a Canon lens eliminates that as a potential factor in the error.

If the issues seem to persist the next step would be to send the equipment to Canon for service.  You may fill out an online repair request form at the following link to setup your repair using our online service.

https://www.usa.canon.com/internet/portal/us/home/support/service-repair

[DoctorDR]

It only happens at Aputure 13-22. It also doesn’t happen when I use the touch screen.

I’m very confused. I’ll try to troubleshoot when I get home.

[Waddizzle]

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@DoctorDR wrote:
It only happens at Aputure 13-22. It also doesn’t happen when I use the touch screen.

I’m very confused. I’ll try to troubleshoot when I get home.

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I am uncertain what you men by “stutter”.  Can you post a video sample?  If you mean the camera is struggling to focus when the lens is stopped down in video mode, then I suspect that it could very well be “normal”

To understand what I suspect is happening let’s look at how AF works when you take stills.  First and foremost, when you are shooting stills through the viewfinder you are employing a separate auto focusing system compared to when you shoot Live View.  

Viewfinder AF uses an AF sensor in the bottom of the camera. The AF sensor would located near where the #2 is shown in the above image.  The mirror reflects most of the light straight up to the pentaprism, #7. Some of the light gets reflected straight down to the AF sensor.  #8 is the diopter in the viewfinder.  What is important in this diagram is that the camera focuses the lens at maximum aperture, which allows in the most light.

When you are using shooting video or using Live View, the mirror swings up, as shown by the arrow, and all of the light hits the image sensor.  No light is reflected down to the AF sensor used for viewfinder shooting.  All AF is performed by the image sensor.  ( Note, Live View can be configured to drop the mirror, focus, and capture an image, but that is off-topic. )

When Shooting Live View stills, the camera still keeps the aperture wide open for better metering and focusing.  Live View has an Exp.Sim, Exposure Simulation, mode where it can stop down the aperture and show you what the actual exposure looks like.  Focusing becomes degraded when you do this, however.  People usually activate the mode momentarily to see what the exposure should look like.

But, when you are shooting video, the aperture is set to whatever you set it to.  If you have stopped the aperture down to f/16 to f/22, then you have dramatically reduced the amount of light reaching the image sensor for focusing.  I suspect that this dramatic reduction in light reaching the sensor is why the camera seems to struggle with narrow aperture settings.