IDguy Loc: Idaho

Yes

Gene51 Loc: Yonkers, NY, now in LSD (LowerSlowerDelaware)

I've gone the other way. I had a 50-500 with my DX Nikons, then got a 600mmF4 with my full frame, decided I was missing too many shots because of the tripod which was a necessity with a lens and camera that weighed nearly 13 lbs, so I opted for a zoom. Looked at all the possibilities for Nikon and ended up with the 150-600 Sigma Sport in 2016. In the year after I got the Sigma I took the Nikon out exactly 3 times. I've never put the Sigma on a tripod - I consider it my "walk around birding lens". I don't miss the Nikon lens - the Sigma is every bit as sharp, particularly at F7.1-F8, which is where I normally have my aperture set anyway. I've since used two different Tamron G2s and found them to be just as sharp at 600, and even sharper than the Sigma at shorter focal lengths. I can unhesitatingly recommend either. I would pass over the original Tamron or the Sigma Contemporary - not the same build quality or sharpness.

I have a birder friend that uses a 5DMk3 and 5DMk4, a 400mm F5.6 and a 100-400 II, sometimes with a 1.4 TC and gets excellent results. She also does not use a tripod.

https://untamednewyork.smugmug.com/search#q=tanager

Scruples Loc: Brooklyn, New York

One of the many neat accessories I have seen is a bracket that supports long zoom lens. It supposedly facilitates focusing while on a tripod.
As for a 1.4 X teleconverter I have one but it does have a few deficits. As for camera shake a large lens does present a challenge. With out a bracket and tripod, folding one’s arms and resting the lens may not be the best idea.

I definitely have my homework cut out for me.

Happy Shooting!

Scruples Loc: Brooklyn, New York

Those photos on Smug Mug are absolutely delightful. They are absolutely tack sharp!

Thank you for sharing!

tcthome Loc: NJ

Shutter speed? Handheld?

venkatesh_eng

Sell your 5Dmk IV and get the latest and greatest R5. As for the lens buy the RF 100-500 L series or the RF 800 mm. You should be able to pretty much nail any bird out there with its animal and bird eye focus. Also should be much much lighter in weight than a big Prime lens attached to a tripod . And you may not need a tripod because the R5 has the IBIS and should be good upto 8 stops. Something to seriously consider before you purchase.

Notorious T.O.D. Loc: Harrisburg, North Carolina

I would think about the 300 f/2.8 if you are serious about the cost of a 500 prime. Add the canon extenders and you still have a very sharp setup and a couple length options. Plus you will have a few thousand dollars for lunch.

Depends if you want to zoom with your feet or not too...

Notorious T.O.D. Loc: Harrisburg, North Carolina

I have a RRS long lens support and there are others.Your lens decision should come first in my opinion.

jimvanells Loc: Augusta, GA

I agree with Chg_Canon. I have the 150-600 Sigma sport and it is one heavy dude. It is sharp but if I had it to do all over, I would have bought the 100-400II and used a 2x for the reach. I traded in the 100-400 early version and test both lenses and liked the reach of the Sigma. I have not been happy with the Sigma 1.4x converter.

MountainDave

Your images are likely blurry from poor AF, not camera shake. Do some research on various long zooms and you'll find the 100-400L IS II is the superstar. Buy a 1.4X for 560mm. Yep, its more money but it is the best and built like a tank as well. A cheaper alternative that is very sharp is the 300 f/4L IS but it is not as versatile and the AF not as consistent as the zoom. With a 1.4X, you get a 420 5.6 and is still very sharp. BTW, I use mine handheld all the time. The IS is so good, I get sharp shots at 1/50.

Gampa

I agree with CHG CANON’S comments. The EF100-400L IS II is an awesome lens.

Architect1776 Loc: In my mind

For what you want to do it sounds like you really do need a Tamron 150-600mm G2 lens.
I do not have one but they have a very good rep here and are highly regarded in reviews on the internet.
So should you? Only you can make the should decision as it is your money. But for the results you want it seems like a logical way to go to get the images you want.
Then you can post those tack sharp photos here and elsewhere with pride in a job well done.
Good luck in your decision.

williejoha

You can hardly beat the 100-400 L II with aN 1.4 extender. My favored setup for shooting Eagles in flight along the Mississippi. Good luck.
WJH

Blair Shaw Jr Loc: Dunnellon,Florida

AMEN...

Blair Shaw Jr Loc: Dunnellon,Florida

Wonderful example....totally agree.