EOS R7 won't recognize Sigma 120-300mm F2.8

[JRichards2012]

I recently purchased a R7 with the purpose of pairing it with my Sigma 120-300mm F2.8 Sports.  However it will not recognize the lens. That lens works perfectly with my adapted R6. And the R7 works just fine with other adapted Sigma lenses. Yet refuses to recognize that Sigma lens that i purchased it for. I have cleaned the lens terminals, taken the battery out of the camera, and replaced.  It still will not work.  I updated the firmware to 1.6.0 as well. Nothing works. Any information on this would be greatly appreciated.  

[ctitanic]

Hi JRichards2012,

Canon has officially stated that they do not support third-party lenses for their R platform, which means compatibility with non-RF/Canon lenses may vary. In light of this, I recommend researching user experiences thoroughly before purchasing any lens that isn't part of the RF lineup. This advice extends to EF lenses, which—while often usable with an adapter—might not provide the same performance or full compatibility as native RF lenses. Checking user reviews and forums can provide insight into the functionality and reliability of third-party or adapted lenses on the R platform, helping you make a more informed decision.

Now, there is something that you did not mention in your original post, what adapter are you using, is it the Canon EF to RF adapter or a 3rd party adapter? If it's a 3rd party adapter you are adding another unknown variable to your compatibility equation. The R7 is very peaky regarding compatibility with any lens that it's not an RF-S lens. There are people online that keep track of those lenses that do work with this camera. I would recommend you to look for those lists.

[JRichards2012]

I used both the canon EF/RF control ring adapter and a third party adapter.  

[JRichards2012]

In addition.  The R7 has zero problems working with the Sigma 85mm f1.4 Art lens. It isn't on the Sigma to R7 compatibility list. 

[ctitanic]

Correct. Sigma's list will not mention any EF lenses. I think that If you have read the other posts in this long thread you may have gathered that there is nothing that can be done in your case. No all lenses regardless of the maker work well in the R7. It's a very peaky camera.

[Tronhard]

Eloquently expressed Frank! 👋👏👋

[ctitanic]

Thanks!

[March411]

I couple thoughts on this topic. Canon has not stated they will not support Sigma products and recently entered into a strategic relationship approving Sigma to manufacturer and distribute R series glass. Please post the language Canon has released on 3rd party support because I have not been able to find it.

Additionally, I have personally received support from Canon support on my 60-600mm F4.5-6.3 DG OS HSM | S, 70-200mm F2.8 DG OS HSM | S and 100-400mm F5-6.3 DG OS HSM | C when I had focusing issues. The Canon representitive was kind enough to trouble shoot the challenges and make a suggestion to resolve the issue. It was a firmware challenge and Canon was the group that assisted in resolution. I am unclear as to why people continue to make this inaccurate statement. They will work with Canon owners to the best of their ability and knowledge but do not support repairs.

JRichards2012, as to your question, there is a compatibility chart on the Sigma site for the R7, your Sigma 120-300mm F2.8 Sport is not on the compatibility list. Currently they only display two.

• 10-18mm F2.8 DC DN | Contemporary
• 18-50mm F2.8 DC DN | Contemporary

[ctitanic]

Well, they will troubleshoot your camera settings, etc. But they will not help you with any thing relative to your 3rd party lens. That's common sense. You will not find in Canon's site or compatibility lists any mention to any other lenses other than the RF lenses. It's just not viable for them to create a compatibility list with all possible 3rd party lenses available in the market. About the relation with Sigma, Sigma has not released yet any RF lens. As far as I recall, there is some RF-S lenses about to be released.

https://www.sigma-global.com/en/contents/sigma_rfmount_lenses/

Note: Sigma compatibility list for the RF mount mention only two lenses no matter what camera from Canon R you select, the two lenses mentioned are APS-C format.

[March411]

They will trouble shoot the entire system to assist you both body and lens, I have done it with Canon representatives. Additionally, if you care to search my site name you will find other instances where I suggested someone contact Canon directly to resolve challenges with third party (Sigma) lenses and they also had positive experiences.

Speaking to Sigma directly, it was part of the agreement to display the Native APS-C RF glass/lenses in their compatibility chart. The EF compatibility chart was removed when they began making native Canon RF lenses. That information, EF compatibility prior to the agreement was always available!

And attempting to use semantics is a poor attempt to cover mis-information. Much like Canon the two lenses I noted above were announced as released, like Canon with a projected ship date. If you go to the Sigma website you will see that you can "Buy Now". APS-C or full frame they are both RF mount so RF has been released by a third party.

If your desire is to purchase strictly Canon lenses that is your choice. But by forwarding mis-information you are not helping people in our field. Being able to make that same choice if they desire to reduce their expense, purchase used, prefer Sigma, any mis-information may stop them from utilizing that option.

Saying that Canon will not assist is simply not true. If it was true Canon would publish statement and would not have assisted me resolve challenges with three lenses when I moved to MILC. Canon is in a strategic relationship with Sigma now, starting with APS-C and with EF lenses. I believe that most businesses support stratigic partners.

Again, please show me where you obtained the documented information that Canon will not offer tech support for Sigma lenses. I may have missed it.