gvarner Loc: Central Oregon Coast

When doing video can you use BBF? Intuitively I think it would be problematic at best. Or does the video feature default to disable BBF? Haven't experimented with this, probably should do that instead of asking.

GoofyNewfie Loc: Kansas City

Not sure which camera you are using, but for the videos I shoot with my Nikon, I switch to manual focus.
In live view, I enlarge the image with the “+” button on the left to get a better look at focus.

gvarner Loc: Central Oregon Coast

Thanks. I have a D7000 and just started doing a few short videos to put in my Pro Show shows for variety.

Bobspez Loc: Southern NJ, USA

Any autofocus whether BBF or pressing the shutter button half way should work. If the subject stays in one place you can just autofocus on the subject and leave the camera on the tripod and start the recording. If the focus keeps changing, manual focus makes sense because it is not as noisy as autofocus if your audio is being recorded on the camera.

mrtaxi Loc: Old Westbury NY, Fort Lauderdale, FL

I shoot video only in manual mode and manual focus. To focus I use a separate Ikan 7” monitor rigged just to the left. To get correct focus prior to a scene one zooms in tight on an eye with the cameras digital magnification system not the lens. If the scene requires adjusting focus during the shoot one really needs a “follow focus” physically attached to the lens. Sometimes it requires a 2nd person pulling focus. If two people are in the scene and each needs to go in and out of focus as the interact, the follow focus attachment has stops to make it easy to preset the focus for each location or distance from the lens in advance. Now for casual video use an STM lens from canon that quietly zooms and use an off camera mic. But this is not as accurate.

jmizera Loc: Austin Texas

BBF is my preference, also supported by manual focus override. I'm assuming your camera also uses the shutter button to stop and start video recording. I don't use continuous auto, but find the one shot auto to be a great asset when things happen fast. I definitely don't want a focus hunt to start as I begin recording.

burkphoto Loc: High Point, NC

Professional videographers and "film makers" generally use manual focus. Autofocus systems sometimes work, but generally have trouble with video. They tend to "hunt" focus.

That said, certain cameras are better at video AF than others. Generally, those with phase-detection AF work better than those with contrast-detection AF. Back Button Focus is worth trying on your camera, but be sure you test it in good light and marginal light, plus high and low contrast situations, to get a feel for it.

The trouble with the dSLR camera market, and some of the mirrorless camera market, is that the video customers of this gear are mostly YouTubers and vloggers (video bloggers) who really have no background in video. They just assume they can and should use AF, instead of learning the strategies of working without it (along with actually editing their footage to "cut in" close-ups and other scenes).