RF 100-400 vs 2x EF 70-200 F4 on an R6

Bigger wrote:

Tazz93 wrote:

Bigger wrote:

drsnoopy wrote:

I can confirm that the EF70-200 f4 L IS (mark i) with the TC 1.4x (mark iii) works just fine on the R5. However it is rather slower to autofocus than many EF lenses, and slightly worse with the TC. I sold that lens and bought an RF100-400 which is the same physical size as the EF 70-200 (actually smaller when you consider you need the adapter too) and in my view a better package - maybe a little better IQ, but twice the reach, and much faster AF. If you can afford it, the RF100-400 is a good option. It isn’t weather-sealed.

I still have my EF 100-400 L mkii and the 1.4 TC, which I will continue to use when weight and size are not an issue.

The EF 400/5.6L has always been a good lens and will be stabilised on the R6, but my understanding is that the max frame rate is reduced. In the UK, a good used 400/5.6 L and a new RF 100-400 are about the same price.

I'd use the RF-400/8 over the EF400/5.6 (I own both). The RF has better contrast (especially if you stop down to f/9), and I like the subjective look of the images better. AF will be faster and more precise with the RF, so you will probably get better IQ on the R body. And IS will be way better.

Odd, all the crops I've seen of the two suggest the L is significantly better (contrast and sharpness wide open and stopped down). Maybe you have a bad copy of the 5.6 L. However, I understand why some prefer the 400 f/8.0 because it seems to work a little better AF wise. That would be a tough call, but I think I'm still on "Team 400L 5.6" in that head-to-head.

A friend let me borrow his 400 5.6, and I was very close to buying my own copy after. I loved the sharpness that lens gave, especially a third stop down at 6.3. I decided to wait for a new optic (likely at a significant price bump) but have still found myself considering that 20+ year old lens here and there.

Maybe my RF copy is good and my EF copy is poor, but I just got the EF back from Canon again yesterday and they claim it is working up to factory specs. I've had it for 10 years, and it's gone up to more than a few crazy high places with me. But even if the IQ is theoretically better on the EF, you will still get more keepers with the RF.

That last statement is why I think it would be a tough call. I thought the 400L 5.6 was one of the lenses that was only "fine" on the R5. Not sure why I felt like it wasn't great, because it focused fine, but for some reason it didn't wow me like others. However, IQ-wise it looked great and was unbelievably sharp for the price and weight. I think the f/5.6 speed and sharpness would win me over though, but it would be a tough call.