It proves they have been drip feeding us lens and camera technology. Everything now is software driven. I still use EF lenses exclusively. They are more than what's required for good photography today.

I use the mark 2 on both the EOS R5 and R3, and for what it’s worth I’ve no issues on either as for accuracy and focus speed

I took my copy out on the R7 yesterday it did ok not quite as good as on my 1DX. Focus acquisition was good enough for birds in flight but acquisition on my DSLR's is quicker. Also at times it hunted quite a bit in situations where I thought it would have locked on quite easily but I have found the R7 to be a bit hit and miss with focus anyway. This lens works on mirrorless but works better on my DSLR's. Since owning this lens it has been my go to, as I know the images I get when I have done my job right are clear sharp images.

Now I’m keen to get one to try on my 1V (film). It’s hard to justify when the 300mm f/4L IS is so great though.

The 1DX mkII has a coprocessor design. The R6 does not. Even though the R6 has a better chip, there's no way it can compete with a camera designed for pros with a coprocessor to help manage the focusing algorithm. The R6 is slower because it can't decide on the focal length as fast as a camera designed for pros where you off-load focusing to a coprocessor. This would be like trying to compare the R3 and the R1 just because they have similar body shapes and sensors. As speculated by others, the pro-grade battery may be able to flow more amps to the focusing motor (essentially a design deficit built into the cell structure of smaller battery) but I've never read anything to confirm a lessor MAh release speed. I'm always glad to have the longer battery for duration but haven't seen proof of an increased flow of amps.

RF lenses certainly will be quicker on the R6, though EF lenses especially 2nd generation and up can keep up (i.e. EF 70-200 2.8 iii). with the 300 2.8 IS, I have good results with more stationary or slow moving subjects; Bird in Flights work ok with focus limiter and good light.This is due to the older generation of lens motors which the newer R cameras cannot use efficiently. And yes, the R6 mark 2 has better AF than the R6 mark 1; it is more closely to the R3, sometimes better than the R5! Keep on with the review and experience sharing of older EF lenses and newer R cameras; it is enjoyable to see and hear about alternatives to expensive lenses 🙂

I too am a fan of using older gear as it presents itself as a great value in many cases. I personally still use the 7DM2 and it does the job still. Did you feel like your setup (mirrorless with the EF 300mm) could keep up in a bird in flight scenario? Also do you feel like the drop in fps makes it unusable for birds in flight? I see used copies of EF800mm in the $5-6K USD range, do you ever see yourself picking up one to play with?

these are lovely photos! great video, is this the mk1 or mk2 of the 300 2.8 is?

Great video Joe, thanks! I have been considering this lens for a while with my 1DX Mark 1 to replace my 400mm f/5.6! Any thoughts?!

Cak rencana kan aku arep tuku lensa ngono kui tapi aku ragu kuatir salah pilih Umpomo aku nyileh lensamu disek piye Utowo tak sewone wes sedino satos

Is it good for sports photog, running to be specific?