100-400mm zoom lenses are some of the most popular out there, offering a versatile focal length range that can tackle a wide range of scenarios including everything from sports to wildlife photography and more. The Canon RF 100-400mm f/5.6-8 IS USM is one of the more affordable options among such lenses, though it still offers some impressive performance and features, and this excellent video review takes a look at just what you can expect from it in practice.
Coming to you from Jan Wegener, this awesome video review takes a look at the Canon RF 100-400mm f/5.6-8 IS USM lens. Of course, with relatively narrow maximum apertures, the 100-400mm f/5.6-8 brings with it some limitations compared to higher-level lenses, but with that tradeoff, you get a much cheaper price ($649) and a more portable build. As Wegener details, perhaps the greatest challenge is getting a clean background, but that is a simple limitation of physics, not this specific lens. Otherwise, if you are looking to save a bit of money or avoid lugging a giant lens around, it looks like an excellent choice. Check out the video above for Wegener's full thoughts on the lens.
I have the 100-400mm f5.6, and I am often wishing that it had a bit larger aperture.
Many hundreds of times, while out shooting, have I thought, "I wish this were f4.5 or f5.0, instead of f5.6"
Never have I thought, "I wish this had cost a bit less" or "I wish this were a little lighter or smaller."
Hence, I don't think that the 100-400mm f5.6-6.8 would be a good lens for me. I put a very high value on a lens's capabilities, and very little value on affordability or portability.
However, if this 100-400mm f5.6-6.8 had an extremely short minimum focus distance, to produce almost 1:1 macro-like results, then I could see it being very useful to me for herp-specific outings ... but only if it had world-class image quality with respect to sharpness and bright corners with no light falloff at the deepest corners of the frame.