Canon R5 + 70-200mm f/2.8 is usm III focusing issue (with canon control ring adapter)

[ToniK]

Hi, 

I'm having problems with my R5 + 70-200mm combination. I'm shooting indoor sports (in a good lighting) and usually before the last period the camera starts to act up. The focus gets blurry and pressing the focus button no longer does anything. Focus/finder gives a red square at the edges of the screen and stops working, it kind of gets stuck trying to find the right focus. I tried to take the batteries off and cool down the camera between periods but it's seems to have zero affect. 

I usually just give up and change the lens but it would be nice to shoot with a lens that gives the best pictures instead of having to change your entire shooting style because of a problem. I'm not entirely sure if this problem started after I updated my camera to the latest software version.

[Stephen]

Hi, ToniK! 

I’m sorry to hear that you’re having trouble with your gear. To help the community assist you better, we need a bit more information:

- What is the exact model of your lens? We have a few different versions of the 70-200mm. 
- Are you seeing any error messages on the LCD or in the EVF besides the red square?
- Are there any other accessories attached to your camera when this happens? 
- Have you been able to test the lens on another body?

Any additional details you provide will help the community better understand your issue.

If you are in the United States and need urgent support, please click HERE to visit your My Canon Account for personalized support options.

If you are outside the USA, please click HERE to find support options for your country.

Thank you, and have a great day!

[deebatman316]

I own this lens with a different camera the EOS 5D Mark IV. When does it fail to AF. Usually sports are in dim lighting even indoor sports can be challenging. I’ll ping my colleague Rodger who does sports with the same lens. I’ll also ping my colleague Trevor who has the same or similar set up as you. 

[shadowsports]

Greetings,

Please review your AF4 menu - Lens Drive When AF Is Impossible:

https://cam.start.canon/en/C003/manual/html/UG-04_AF-Drive_0110.html

What settings are you using?