https://community.usa.canon.com/t5/EF-RF-Lenses/Ef-to-RF-Compatibility-list/m-p/476489#M31032 <P>I have a Tamron EF 40mm f1.8 that I loved using with my Canon 5D MK II. I purchased the R and the Canon EF to RF adapter. However, that lens does not seem to work on the R once mounted with the adapter. Any idea what's going on? Is there list of lenses that are just not compatible with the R system?&nbsp;</P> Wed, 08 May 2024 13:27:38 GMT scottalanphoto 2024-05-08T13:27:38Z https://community.usa.canon.com/t5/EF-RF-Lenses/Ef-to-RF-Compatibility-list/m-p/476489#M31032 <P>I have a Tamron EF 40mm f1.8 that I loved using with my Canon 5D MK II. I purchased the R and the Canon EF to RF adapter. However, that lens does not seem to work on the R once mounted with the adapter. Any idea what's going on? Is there list of lenses that are just not compatible with the R system?&nbsp;</P> Wed, 08 May 2024 13:27:38 GMT https://community.usa.canon.com/t5/EF-RF-Lenses/Ef-to-RF-Compatibility-list/m-p/476489#M31032 scottalanphoto 2024-05-08T13:27:38Z https://community.usa.canon.com/t5/EF-RF-Lenses/Ef-to-RF-Compatibility-list/m-p/476490#M31033 <P>There are no guarantees that any particular third party lens will work with an adapter. The 150-600 Telephotos seem to work OK. You might ask Tamron if there is a software update for your lens.</P><P>As for the list, feel free to start one. 8^)</P><P>&nbsp;</P> Wed, 08 May 2024 13:34:49 GMT https://community.usa.canon.com/t5/EF-RF-Lenses/Ef-to-RF-Compatibility-list/m-p/476490#M31033 kvbarkley 2024-05-08T13:34:49Z https://community.usa.canon.com/t5/EF-RF-Lenses/Ef-to-RF-Compatibility-list/m-p/476496#M31034 <P>Canon only makes compatability list for their own gear. It's up to the 3rd Party to ensure compatability with Canon cameras. Canon never said that Tamron lenses are compatible with it's mount.</P> Wed, 08 May 2024 14:10:01 GMT https://community.usa.canon.com/t5/EF-RF-Lenses/Ef-to-RF-Compatibility-list/m-p/476496#M31034 deebatman316 2024-05-08T14:10:01Z https://community.usa.canon.com/t5/EF-RF-Lenses/Ef-to-RF-Compatibility-list/m-p/476506#M31036 <P>It really isn't a question about whether will it work or not. It is how well will it work.&nbsp;<SPAN>I believe t</SPAN><SPAN>he option to allow the shutter to release without a lens can be found under Custom Function 4 of the menu. It allows almost any lens to "work". How well is the question.</SPAN></P> Wed, 08 May 2024 14:41:59 GMT https://community.usa.canon.com/t5/EF-RF-Lenses/Ef-to-RF-Compatibility-list/m-p/476506#M31036 ebiggs1 2024-05-08T14:41:59Z