EF 100-400mm vs RF200-800mm vs RF100-500mm: Best for birds in flight?

[Ceddy]

EF100-400mm f/4.5-6.3 IS II USM vs RF 200-800mm f/6.3-9 IS USM vs Rf-500500 f/4.5-7.1 L IS USM

Pairing with a R5 and R7, with all other factors aside, which is the better lens for sharpness for shooting "birds in flight" between these 3 lenses? I currently own the R5, R7 and EF100-400mm f/4.5-6.3 IS II USM.

Trying to decide if upgrading is necessary to achieve sharpness.

[Ceddy]

Thank you, I still haven't had a lot of opportunity to take it out for some good photos. I'm feeling more confident about it however. I appreciate the responses!

[Ceddy]

Thinking that you are on the same page as what I have been told by Canon, you're agreeing that since I already own the EF100-400mm, I wouldn't gain much except the extra reach and then you lose an f-stop with the 100-500mm? So back to my original question for "birds in flight" photography, which is what I wish to photograph mostly, since I already own the 100-400mm, the consensus is to stick with it. If I want more reach, the RF200-800 would be a good choice-but it seems like that's a good choice for more "static" wildlife?

[ebiggs1]

"... but it seems like that's a good choice for more "static" wildlife?"

No that is incorrect. Remember with the 200-800mm you still have the shorter FL that you are using now. The advantage and it is a big advantage, you get the 401mm to 800mm. That you do not have currently. Not having it is a bigger disadvantage then not using it but it's there. You do not get that advantage if you chose to go with the 100-500mm either. The difference between 400mm and 500mm will be slight and if there is any IQ difference it will also be slight if detectable at all.

If you sit down and weigh all the advantages vs disadvantages you will see the best lens Canon has for this work is the Canon RF 200-800mm f/6.3-9 IS USM Lens. Now it makes no difference to me which lens you choose but I will bet you a dollar if you buy the 100-500mm sometime in the future you will wish you had that extra FL. It always happens that way and a lot of people end up buying the Canon RF 200-800mm f/6.3-9 IS USM Lens anyway. Not such a bad thing but it does cost you monetarily if that is a concern.

Some people have to learn by experience instead of form experience of others.

[Ceddy]

Thank you and I agree about the reach however I am looking for birds in flight shot-performance, and what I am understanding is that the RF200-800mm might come a little short with performance vs the EF100-400 or the RF100-500mm. Again I could be wrong and that's why I appreciate the feedback. You're correct, I will probably end up with the 200-800mm also or just rent it when I am need of more reach. Sorry I am so sporadic with responding, busy summer. Thank you!

[ebiggs1]

"... I am understanding is that the RF200-800mm might come a little short with performance vs the EF100-400 or the RF100-500mm."

There is nothing the 200-800mm can't do that the others can do. And there a lot the 200-800mm can do that the other can't do like shoot at 800mm or 700mm or 600mm or 501mm. This a no brainer question as I will almost guarantee you like almost everybody else that doesn't buy the 200-800mm you will say I wish I had more FL. Canon was brillant to make their super zoom in the 200-800mm rage it is a far better useful FL range than to mega popular 150-600mm super zooms.