To all R5C owners, can you please indicate which CANON EF lenses don't work in video mode, so that we can bring it to the attention of Canon engineers who work on firmware updates, as well as warn fellow users which lenses to stay away from in the time being? I know certain third party lenses have issues, but you would think that Canon would at least support their own lenses, but this doesn't seem to be the case at all.
It would be good to compile a list of which ones aren't recognized by the camera's video menu with the "attached lens not supported by the camera. Lens will not work." message. (Edit Nov 24, 2024 I've added a photo of the error message)
To start:
Canon: 17-35mm 2.8L, 85mm 1.2L, Canon 20-35mm 2.8 L, Canon 14mm 2.8 L
Tokina: 28-70 2.8 ATX
Sigma: 35mm 1.4, Sigma 24-70mm 2.8 (works, but iffy auto focus and poor IS functionality)
Tamron: 24-70mm 2.8 G2 (some work fine and some don't), 70-200mm G2, 35mm 1.4
Edit: As pointed out repeatedly by users below, many third party lenses aren't fully compatible with high (photo) burst modes and that's fine, this topic is meant to focus on Canon's incompatible EF glass in VIDEO mode on the R5C/C70 despite their vague marketing that claims compatibility via the EF-RF adapter (see screenshot, attached). I also peaked at the R5C user guide which does make mention of certain "optimal" lenses, for PHOTO mode and there's no mention of optimal nor incompatible lenses in the Cine menu which is frustrating because often the lenses that are prompting the "lens will not work" message on the R5C in Video, turn work perfectly fine in photo mode or on the regular R5 in both photo & video modes, and on all other R series bodies (R6, R3 etc...). Perhaps this will change with the release of the R5Markii and R1.
