RF-S3.9mm F3.5 STM DUAL FISHEYE switches to MF unexpectdly.

[Udder]

The AF switches to MF whenever you (accidentally) touch the left side of the screen (which is actually the right lense view). To fix it you need to touch the right side of the screen and then you can recenter the focus area by pressing the joystick. So I think it is a firmware bug in the camera. I really hope Canon is monitoring this and will make a fix soon.

They should have made the left side inactive to touch and also they should have made the pressing down of the joystick works no matter where the focusing area is. Right now if the focus area is by accident on the left and you press the joystick the focusing area recenters but on the left (MF) side.

One trick I found to help with this problem is to turn on the Menu->AF->MF peaking setting->ON

In this way when I am using the Eye View Finder and if the AF is in Manual I usually see a lot of red color indicating that I am out of focus. (It’s hard to see the red indication on the screen)

[John_Q]

Hello Udder,

I'm sorry to hear that you are experiencing an issue when using you RF-S 3.9mm F/3.5 STM Dual Fisheye lens. I do not see what camera body you are using mentioned. You may want to contact our phone support to report the issue along with the camera model being used so that we can submit a report to engineering as to what is happening and what gear is being used. This sort of information helps and is considered when they do look at possible updates based on what customers' needs and wants are as well as fixes if applicable. If you would like to speak with a Canon representative, please contact our Technical Support Team at 1-800-652-2666, Monday through Friday between 9:00 AM to 6:00 PM ET. 

[Udder]

I’m using R7 and I heard exactly the same experience from another user of this lense. There isn’t much else for me to add here. It is clearly a small and very obvious bug in the software and I hope Canon will address it soon. 

[deebatman316]

Are you sure you're not accidentally hitting the AF/MF on the camera body. Some RF & RF-S rely on the switch on the camera body. Those lenses don't have that switch on the lens itself.

[Udder]

The switch is on AF mode. It is easy to reproduce. You tap on the left side of the screen and an MF sign appears on the display, you tap on the right side of the screen and the sign on the display switches to AF all without touching any other switch on the camera