EOSEFSRFISUSMDIGIC
Newcomer
- Joined
- Jan 27, 2026
- Posts
- 4
- Likes Received
- 4
- Points
- 3
- Name
- G
Hey there.
TLDR: Adapted Sigma 100-400 C (EF) on a new R6mkiii. AF is better than my old R but not the leap I expected, probably the Sigma's weak AF plus the adapted-EF hit. I only shoot daylight sports (soccer, baseball, water polo) and want to keep the next lens 10+ years. Leaning native: RF 100-500L vs the cheaper RF 100-400. Worth the jump to the 100-500L? Anyone with firsthand AF experience, would love to hear it.
Not TLDR: For context, I bought a Sigma 100-400mm C about 4 years ago to shoot my son's soccer games. It was coupled with a Canon EOS R. At the time I knew it would be a challenge of its own due to the very low fps of the R, but it managed to take decent shots tbh.
Since then I've used it to shoot baseball and water polo games, always been a blast and fun.
Wanting to take this to the next level, I replaced my 8yo R with an R6mkiii. It's been a joy, definitely pulling more fps and better AF than the R. However, it doesn't feel like the leap I had expected on the AF front. It's better but not what I would expect.
Then I did some research and it seems like this Sigma when adapted to an R system is known for low AF performance, which could explain what I'm experiencing (e.g. servo mode tracking a subject and after a few frames it starts blurring and losing focus).
I read about EF-adapted vs native RF lenses and the fact that it could lower AF performance due to older motor technology, and that Canon nerfs the performance of third-party lenses on the fps front.
I also looked at options in the native field. The RF 100-500L would do the job since I only shoot during daylight. The 100-300 f/2.8 is beautiful but not justifiable price-wise
. The RF 100-400 could be another option, "only" single Nano USM but a lot cheaper. I'd want this time to keep the lens for a decade+ if possible.
Does anyone have experience with this? Who could provide feedback?
TLDR: Adapted Sigma 100-400 C (EF) on a new R6mkiii. AF is better than my old R but not the leap I expected, probably the Sigma's weak AF plus the adapted-EF hit. I only shoot daylight sports (soccer, baseball, water polo) and want to keep the next lens 10+ years. Leaning native: RF 100-500L vs the cheaper RF 100-400. Worth the jump to the 100-500L? Anyone with firsthand AF experience, would love to hear it.
Not TLDR: For context, I bought a Sigma 100-400mm C about 4 years ago to shoot my son's soccer games. It was coupled with a Canon EOS R. At the time I knew it would be a challenge of its own due to the very low fps of the R, but it managed to take decent shots tbh.
Since then I've used it to shoot baseball and water polo games, always been a blast and fun.
Wanting to take this to the next level, I replaced my 8yo R with an R6mkiii. It's been a joy, definitely pulling more fps and better AF than the R. However, it doesn't feel like the leap I had expected on the AF front. It's better but not what I would expect.
Then I did some research and it seems like this Sigma when adapted to an R system is known for low AF performance, which could explain what I'm experiencing (e.g. servo mode tracking a subject and after a few frames it starts blurring and losing focus).
I read about EF-adapted vs native RF lenses and the fact that it could lower AF performance due to older motor technology, and that Canon nerfs the performance of third-party lenses on the fps front.
I also looked at options in the native field. The RF 100-500L would do the job since I only shoot during daylight. The 100-300 f/2.8 is beautiful but not justifiable price-wise
. The RF 100-400 could be another option, "only" single Nano USM but a lot cheaper. I'd want this time to keep the lens for a decade+ if possible.Does anyone have experience with this? Who could provide feedback?
Last edited:
