Adapted EF Sigma 100-400 C vs Native RF lens FPS, AF etc...

[EOSEFSRFISUSMDIGIC]

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?

 

[MSH411]

Have you tried to update the firmware on Sigma 100-400mm? The performance on mine and my 60-600mm improved greatly after the update.

I own the RF100-500mm and the 100-400mm and both perform excellently, either would a good choice. The 100-400mm is much easier to carry all day and offers nice IQ if price is part of the equation.

 

[EOSEFSRFISUSMDIGIC]

Thanks for the suggestion, their last firmware update was oct 22 2020 so my lens already has that version and no further updates to be expected...

Do you think the 100-400 would be ok in a water polo game with lots of spashes and quick moving action? Do you notice a difference in AF between the 2?

 

[MSH411]

In low light I depend on the RF100-500mm as I gain a stop on both the short and long end. Most would say it's subjective but I find the Dual Nano USM motors make the 100-500mm much more responsive even in low light over the 100-400mm. Photographing water polo indoors and the available light will be the biggest factor on the response time of both of these lenses.

 

[EOSEFSRFISUSMDIGIC]

Thanks MSH411, yes that makes sense. I would think a dual nano is faster than a single one unless the weight of the glass impact the performance. I think I'm leaning towards the 100-500.

The only technical detail I'm still not sure about is if it's real that the old Sigma lens has poorer AF performance due to the old motor and the canon AF engine translation... It makes sense.

I think I'll just rent out a 100-500 for a week and see for myself

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[MSH411]

Renting is always a good plan prior to making a large investment in glass.

The other obstacle with the Sigma EF is the communication protocols. RF lenses have a 12-pin connection to the camera, while EF lenses have 8 pins. This allows RF lenses to communicate with the camera faster and more efficiently.