R8 buffer freezes after taking one photo

[Gravity]

When I take a single photo with my R8 camera using the Cannon EF mount adapter and my Rokinon14mm F2.8 Full Frame Ultra Wide Angle (w/ built in chip), My R8 will freeze up on me. The screen goes black, the shutter fires like it is taking a picture, the red buffer light turns on, and it gets stuck like this indefinitely. Not only do I have to turn off the camera, I need to remove the battery.

The 14mm Rokinon lens works with my EOS Rebel T7.My Cannon EF to RF adaptor works with my Sigma 70/200mm lens. I turned on "Release shutter without lens." I have not seen any more suggestions on any forums. 

[stevet1]

Gravity,

You might look to your memory card. Either re-format the one you've got, or buy another.

Steve Thomas

[March411]

To Steve's point, exactly what memory card are you using? Normally a buffer challenge is connected to the card.

Have you tried another card?

[kvbarkley]

You might also turn off lens corrections, the camera should just ignore corrections for the lens, but if it is reporting itself as another lens, it may confuse the camera.

[Gravity]

I did some more troubleshooting and am less optimistic of a solution.

All of my gear works with other products. It seems like a software issue between the Rokinon lens and the R8. My SD card is a 256GB 200Mb/s v30. Taking a single picture should be fine and it works specifically with every other lens. When I listen carefully the Shutter never closes and I think that is why the red buffer light is stuck on. The "solution" is to put tape over the pins on the Rokinon lens. However, this means I'm stuck in whatever aperture I used last on my Rebel T7.  

Turning off lens corrections did not help, but it made me notice that when the pins are not covered the camera has a weird bug where the aperture doesn't show up at all. Normally the screen should say "f00" when the camera is not connected to the lens. Instead the aperture section is blank. Please let me know if there is anything I can do on my end. 

This is how the screen looks when the pins are uncovered. There is no aperture value.

[stevet1 · Accepted solution]

Gravity,

Yes, the aperture is a function of the lens, not of the camera. If your aperture is showing a blank screen, it means that the camera is not electronically communicating with the lens.

You wrote, "Taking a single picture should be fine and it works specifically with every other lens."

Time for a different lens, methinks.

Steve Thomas

[Waddizzle]

I noticed that you are using Tv mode.  That mode requires the camera to control the aperture, which it is unable to do.  

With a fully manual lens you should be using either Av or M.   You may also might want to enable the setting that allows you to “release shutter without lens attached.”

I didn’t pay attention to see if anyone else asked about the brand of mount adapter.  You only want to use Canon mount adapters.

[lmmeredith]

I have the same problem. Have a Canon R8 with a Canon mount adapter. Using a Tamron 28-300 F3.5-6.3 lens. Works if auto focus is OFF, but when it’s ON the camera freezes. Need to turn the camera off and remove the battery. Based on the solution provided I am assuming the communication between the camera and the lens for auto focus is not working.

i have tried several cards as well as reformatting them and that doesn’t solve the problem.

[March411]

Hey lmmeredith,

We recently helped another Tamron owner resolve a R body conflict by suggesting they update the lens firmware. They were lucky and had a Tamron office with a short drive from their home. The firmwar update was completed and the lens (older version) worked once the update was completed. I looked at your lens on the Tamron site and a message was posted Jan 15, 2020 that stated:

New firmware version makes the model compatible with Canon EOS R series cameras (*1) and Canon "Mount Adapter EF-EOS R" for general operations(*2).
(*1) Compatible cameras: EOS R / EOS RP / EOS R5 / EOS R6

Might be worth trying the update if you have the means to do it easily.

[lmmeredith]

Hey Marc

Thanks For the information! I will try updating the firmware and let you know if that solves the problem.

— Lynn