>>3216092Canon's STM lenses are supposed to be their video friendly lenses. In my experience with the 40mm STM, it's still a little noisy. An alternative would be to either have an external mic, or record audio separately and sync it with software. The most silent focusing lenses for DSLR are all manual focus.
The Canon 100-400 zoom (the discontinued original version, not the newer "mark II," which is even better) is a very, sharp good lens, if a bit heavy. I used to own one, but sold it when I got out of photography for a while. Pic related is a 100% crop I took with my old one so you can "pixel peep" at the details. This was hand-held, so I had the ISO fairly high to compensate for any motion blur.
At the longer end, you're going to want to have good lighting, a tripod, or else use a fairly high ISO to get acceptable shutter speeds, but the 80D should be able to handle it just fine at ISO 800 or so without significant image quality loss. There aren't a lot of 400mm lenses that are faster than f/5.6, so unless you want to spend significantly more money, getting a used Canon 100-400 (mark I) would be a good option. The Sigma 100-400 and 150-600 are also good options. I don't own either, but I like the look of the Sigma 100-400 because it tests sharp in lab tests, has a ring zoom, has a more modern image stabilizing system than the original Canon 100-400, and is also a half pound lighter than the Canon 100-400.
