Zoom Canon RF 100-500mm F4.5-7.1L IS USM

Even without the 1.4 extender this lens is a beast! Looking forward to shooting the Blue Angels next year. Took it out to the harbor to shoot pelicans in flight (offhand) and into my first astrophoto attempt with Jupiter. Thrilled with my results! Really heavy, tough to shoot offhand!

A lot has been written about this lens - and I have yet to see much negative written. Some QC issues on earlier copies and lens elements cracking but nothing of late and a truly awesome lens in my opinion.

I had the old EF 100-400 Mk I and thought it soft over 300mm. No such issues here !! This is one incredibly sharp lens and I have been blown away by it's performance.

Weight is OK.
Speed of focus good.
Sharpness and contrast ... well, awesome !
It is easy to handle and it's macro ability is shown all over the web.
The only downside I see is cost.
I do not use it a huge amount but I am glad I got it over the 600 or 800 lenses. I use it when I shoot birds ... I guess it need a tele converter but ATM i take the picture and crop as with an R5 the IQ is stunning.

I have using for last 6 months. I have uswd it in heavy rain and in very dusty environment and it focused flawlessly with sharp images. Most important is that it is light weight and focusing is accurate in light cloudy day and on sunny day.
Lens stabilization is excellent so one can get sharp hand held photos. Tripod collar is strong and fits snugly.

I've had this lens for about 6 months. Got lucky at a local dealer and he just happened to have it in stock.
I have an R5 and was using a EF 2.8 70-200 with converter. Shooting shooting regular games I can get on the field without a problem, but during tourney's they usually don't want you inside the fence. This lens has great reach and paired with the R5 and a monopod, just excellent. Build quality is what you would expect from the L series line.

I guess the only thing that might be nice would be to have a lock to keep the lens from moving, there is a tensioner but it doesn't tighten enough for me.

These 2 shots were taken from outside the outfield fences.

I purchased the lens after I got the R5. Had to wait about 2 1/2 months for it but was worth it.
I mainly use it for Birds, Wildlife and Airplanes. Also good for landscapes.
Is far superior to the original 100-400L I owned. Did not have an opportunity to try the mkII version of that lens.
The only negative I have about that lens is the price and maybe that it is not a metal lens, but this might turn out not to be a problem.

This is a great piece of glass and solidly built as you'd expect for an L lens.

I picked one up in Asia as I was keen to try out some sports or wildlife. This didn't disappoint and was great with the eye or animal tracking on the R5.

I also use it for events, and again, the eye tracking is great, but the lens keeps up no problem.

It's a little heavy when you have it on all day, and slightly annoying there's no lens lock to stop the tube creeping out (is has a tighten/loosen ring to create more or less friction).

It comes with a tripod mount and the tough bag with a strap for carrying. Oh, and the lens hood has the nifty wee door so you can get to your CP.