Sigma 150-600 Contemporary won't communicate properly with R5 and R6 since firmware upgrade

[markphoto]

I'm using the Sigma 150-600 Contemporary with an EF-R adapter on my R5 and R6.  It worked fine, until I upgraded the camera firmware to the latest version.  Since then, I get an Error 01, "Communications between the devices is faulty.  Check the camera, lens, or mount adapter contacts". 

I have tried cleaning all the contracts with isopropyl alcohol.

Has anybody encountered this problem?  Will upgrading the lens firmware solve the problem?  I would have to purchase the lens dock to do this.

[Waddizzle]

“I recommend only Canon adapters, and they are the only ones that Canon supports - which does not imply they support third party lenses attached to them.”

Of course, I totally agree with that recommendation.  Like I pointed out above, if you are using a third party mount adapter, then the odds are high that is the issue.

[markphoto]

I read that the other way around somehow.  I do use Canon adapters.

[Tronhard]

Given you use Canon adapters, I would recommend checking that status of the lens own firmware version.  While Sigma clearly states that they do not guarantee that their lenses perform with R-series bodies, having the latest firmware installed on the lens is always a good move.   I have the latest firmware on my Sigma lenses and upgraded to 1.6.0 on the R5 and R6 bodies with no issues.

[ebiggs1]

"I have tried cleaning all the contracts with isopropyl alcohol."

Stop doing that, it very rarely to never helps and can make things worse. Much worse!

"I'd contact Sigma to see if they are aware of the problem and have a solution."

I would too. Canon does not make their cameras work with off brand lenses. It is up to the lens maker to make sure the lens works on a Canon body. I think this might be an ongoing problem as I have heard of it from several different people.

As to the Sigma dock, I would buy it, I did. It is of little use 99% of the time but when you need it, it is a nice to have unit.  It isn't expensive. If it were much more expensive I would advise you don't need it. Sigma used to, they may still do so, update your lens FW for free. But you have to send the lens to them. A hassle, expense, for sure that the dock  eliminates.