How do you use your 100-400m when shooting BIF?

Please let me explain. I found this website http://www.bushhawk.co​m and it made me wonder how people use their lens.

The way I shoot anything with my tele is this way, I use my left hand for focusing and changing focal lengths, and the right hand for shutter/AF and camera controls. This method probably have more control on framing as compared to the method below.

Well it got me thinking after seeing this site. Lock the 100-400mm to the 400mm, switch to AF. This leaves my left hand for the sole purpose of supporting the lens. This method probably calls for more cropping. But is it relevant? as the majority probably requires some sort of cropping anyways.

I'm not sure if I am explaining myself well, but I wonder how many people actually use their 100-400mm like a prime when shooting bird in flight.

i probably shout use it like a prime for BIF and most birds for that matter.
However, I pull back to like 200 or so then get the bird in my viewfinder. then zoom out to 400, refocus and shoot (hope and pray).

jhayesvw wrote in post #13785617
i probably shout use it like a prime for BIF and most birds for that matter.
However, I pull back to like 200 or so then get the bird in my viewfinder. then zoom out to 400, refocus and shoot (hope and pray).

I believe this is what most people do. But as I noticed on the Bushhawk site. Some of the photos on that site. The left hand is not even touching the focusing ring. And it just made me think how many people just use it this way. Or how practical it is.

I probably use my Sigma 150-500 the same way a lot of people might use their 100-400. I use the left hand to support the lens and also to push and pull the lens through the focal range. Then I use the shutter button on the camera to focus. I don't use the focusing ring at all unless I have to manual focus through branches or something.

Same here with my 100-300 5.6L zoom out a bit till you can get them in frame then track and focus while zooming back in.