02-10-2026 02:13 PM
Looking at picking up a lens to shoot birds and other wildlife with. I know some of these lens’s pair better with crop bodies like the R7, but my current body is an R6Mii. I would prefer the Sigma’s over Tamron because the zoom ring rotation. Do all Tamron’s turn opposite of Canon and Sigma? I know this is quite a list but as I read through posts and articles, I take notes as to what people are using and these seem to pop up a lot of the time. If you had to pick the best one out of these as far as reach and sharp images which, would it be? Or I’m open to other suggestions as well.
Canon EF 100–400 mm f/4.5–5.6L IS I
Canon EF 100–400 mm f/4.5–5.6L IS II
Canon RF 100-500mm F4.5-7.1 L IS USM
Tamron SP 150-600mm f/5-6.3 Di VC USD G2
Canon RF 200-800mm F6.3-9 IS USM
Sigma 150-600mm F5-6.3 DG OS HSM Contemporary
Sigma 150-600mm F5-6.3 DG DN OS Sports
Sigma 150-600mm F5-6.3 DG OS HSM + TC-1401 1.4x Teleconverter Sports
Sigma 150-600mm F5-6.3 DG OS HSM + TC-1401 1.4x Teleconverter Contemporary
02-10-2026 03:01 PM
Hello @Ovacheerdad
That a decent list of lenses to consider and most are close in price range with the exception of the Canon RF 100-500mm F4.5-7.1 L IS USM which will cost a bit more then the rest.
I have owned and shot with three of the lenses on your list, all three will produce very quality images. They also performed great on my R6 MKII but all my Sigma's needed firmware updates when I moved to mirror-less, lens racking and problems locking focus. Once the firmware was updated they performed well but did not give me the same burst rates as the Canon lenses.
The sigma was sold/traded when I picked up my Canon RF 100-500mm F4.5-7.1 L IS USM. I rented the RF100-500mm and the focus response was so much better that it just made sense.
If budget is a concern my first choice would be the Canon RF 200-800mm. Even with it being a stop slower the R6 MkII can manage the slower lens. It will give you additional range, it will not be an adapted lens and you will be building into your current system. You will also benefit from all the camera features as adapted lenses do have some limitations. At the point if you can swing it I would purchase only Canon, I loved my Sigma's for many years but overall the Canon lenses perform better as it pertains to AF speed/lock and you fully utilize all the bodies features.
Good luck regardless of what direction you go, like I said, you don't have a bad lens in your list.
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02-10-2026 07:22 PM - edited 02-10-2026 07:28 PM
I have the Canon RF 200-800mm F6.3-9 IS USM and the R6 MarkII. When the lens came out I did a lot of research on it, once I was convinced that I wanted the lens, I did the research on the camera and came up with the R6 MarkII as the camera I wanted to match the lens to. This was my first Canon purchase, as I was so impressed by the combo, and I have not been disappointed. I was initially slightly concerned that the aperture at 800mm is F9, which is why the low light loving R6 MarkII 24mp full frame sensor is a great match. A 24mp FF sensor has big pixels, so very good for light gathering. I also live along the coast in SE North Carolina, so plenty of light there, and inland is longleaf pine savanna, not a heavy canopy. But actually those concerns ended up not being concerns. I'm often shooting birds over the Ocean before sunrise, the autofocus having no problem, and if needed, noise reduction in software is very good these days. The only real limitations are me.
The RF200-800 definitely has the best reach, but it is the only one of these lenses I have experience with, so I am not knocking the others.
Forster's Tern Twilight Dive
Yellow-rumped Warbler
02-10-2026 08:05 PM
Beautiful Shots Tom!
The first shot is using the same setup R6 MkII and the RF200-800mm. It's also great for Macro it ever you decide to broaden your interests.
RF100 Macro
R5 Mk II ~ R6 Mk III ~ R7
Lenses: RF Trinity and others
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02-11-2026 06:26 AM - edited 02-11-2026 06:27 AM
So i was walking through the plant yesterday and ran into a guy here local that shoots wildlife and has had a lot of his prints published. Out of all those he said the IQ of the Canon EF 100-400L II would be the best. He said i may never get the IQ as his primes in early morning/late evening low light as his primes but in good light that would take good shots. He uses a 5mII with a 400 2.8/600 F4. So now im questioning the RF100-500 or EF 100-400 II. As good as the r6mii is with low light and higher ISO would these still produce great shots?
02-11-2026 07:36 AM
I would not buy an EF lens for an R body. It’s one thing if you already had the lens before buying the body, but why go backwards and buy into a lens you must use an adapter with?
02-11-2026 09:05 AM - edited 02-11-2026 09:07 AM
I would lean towards Tom's recommendation of sticking with the RF system but the EF 100-400mm f/4.5-5.6L IS II USM Lens is still a fairly popular lens.
Aperture wise the lenses are equal but with the RF100-500mm you will get 100mm of extra range which is needed for wildlife but at twice the price of the EF100-400mm.
If you can swing it the RF100-500mm may be the better choice for several reasons.
The EF system is slowly moving to end of life or end of service as Canon calls it. If repairs are needed it will not extend out as long as an RF lens and at some point even local repair facilities will be hunting for parts. I understand this is a future concern but I owned all my lenses for a very long time (some 20 years), they should have a long life. The EF 100-400mm may not be able to give you that long life.
R6 MkII - RF100-500mm lens
R5 Mk II ~ R6 Mk III ~ R7
Lenses: RF Trinity and others
Adobe and Topaz Suite for post processing
Personal Gallery
02-11-2026 11:47 AM
Canon RF 200-800mm F6.3-9 IS USM without hesitation.
Marc keep doing what you’re doing those are great.
02-11-2026 12:52 PM
Most appreciated Ernie!
R5 Mk II ~ R6 Mk III ~ R7
Lenses: RF Trinity and others
Adobe and Topaz Suite for post processing
Personal Gallery
02-11-2026 12:54 PM
Marc, Tom and others couldn't have said things better.
I also had the
Sigma 150-600c - sold it last year
I currently own the Canon 100-500 & 200-800
One of my biggest aversions to Tamron is the direction of the zoom ring. I think it can be changed if you buy the tap-in console. Don't quote me on that because I've never owned one myself. My experience is with Sigma Art and Contemporary and their USB dock. You don't have to change the direction of the zoom ring because they match Canon. 😂 Sigma EF (Global Vision) lenses were outstanding on DSLRs. On mirrorless they're very good adapted with a Canon brand adapter. When it comes to mirrorless, you'll want to go RF. Like the others, I don't suggest going backwards. The 100-500 blew me away. The 200-800 definitely has a soft spot in my heart.
Not going to tell you how to spend your money, but +3 on not investing (new money) in EF. 400mm is short for wildlife. Can you squeak by on it. Sure. Do I recommend it, no, for all of the reasons previously mentioned by my colleagues.
~Rick
Bay Area - CA
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