"Finger Frames" are totally a thing and they can actually help you learn your lenses' field of view.
You know exactly what this is but you just didn't know it had a name. Not only do tons of new filmmakers walk around on set using them but they most likely have at least one profile picture somewhere on social media in which they're throwing 'em up. "Finger Frames," or "Director's Hands," is that gesture some filmmakers do to frame up their shots without having to look through their camera's viewfinder—and yeah, I think it's fair to say that most people that do this are pretending to know what they're actually doing. (I say this as someone who did this shamelessly in college like a friggin' dork ass idiot.)
But Finger Frames can actually work if you know how to use them. In this video, Rubidium Wu of Crismon Engine shows you an exercise that will help you learn how to measure the field of view of each of your lenses so you can frame up your shots without being tethered to your camera. Check it out below:
As you can see from Wu's video, this exercise is super simple and straightforward. It's a great little trick to learn for those that are reliant on having to switch out lenses to actually see their field of view.
If you're not too fond of the whole hand thing, you can always buy a director's viewfinder, which will allow you to see the fields of view of many different types of lenses, video formats, and aspect ratios, however, these things can get pretty expensive if you want one with lots of features. Either way, whether you're into Finger Frames or not, it's a pretty useful skill to have—being able to determine the field of view of each of your lenses.
Do you use Finger Frames? Are you doing Finger Frames in any of your profile pictures? (Be honest.) Let us know down in the comments.