The common interpretation (certainly on this thread) is "2 way tilt" refers to "tilt up" and "tilt down". But I don't think there is an single official (or standard) definition for almost any of the terms for a rear screen other than "fixed".
Yeah, I'm a technician so to me tilt up and down is only one way (rotation around an axis, is only one movement to me)
so in my head, Fuji style side flipping tilt screens are "2 way tilt", but I can understand how people referring to up / down as two different movements and therefore call simple tilt screens "2 way tilt" as well, and would call Fuji's implementation "3 way tilt"
I guess from now on I'll just say "2 axis tilt" it's going to be a lot simpler for everyone.
There are at least five different implementations I can think of for "fully articulating" as seen on the:
- Sony a7Rv
- Sony a99/a77/etc
- Pentax K1
- Nikon Z8
- Canon/Panasonic/etc
Each one has different advantages and disadvantages. My favorite is the a99/a77 type of articulation, but the a7Rv is pretty close. My best guess is the new Nikon implementation is pretty close as well but I have yet to see one in the wild so I am not 100% sure how it articulates.
To me, "fully articulating" means that it can articulate to face you, wherever you stand from the camera. In that regard, the Z8 and the K1 do not fit that definition, the Z8 being a more advanced design allowing for a wider angle of movement, but ultimately is very similar in use to screen that you'd find on a Fuji X-T2/3/5, and the K1 being a very complicated design but useful only if you stand behind the camera. If you're using a tripod, then the A99 screen doesn't either, as the tripod head would block the view.
I guess we can call them with "ball joints" (it's not really a ball joint but the functionality is very close).
- the classic FA screen as seen in Canon cameras could be called "side ball joint"
- the more advanced Panasonic GH6 / Sony A7RV could be called "tilt + side ball joint"
- the A99 style screen could be called "bottom ball joint"
- the Pentax K1 screen could be called a "rear ball joint"
- the Fuji / Z8 screen could be called "2 axis tilt screen"
I think that could help clearing out a lot in screen articulation debates where no one is able to know what we're talking about
To my eyes, every screen design shows compromises, except the A7RV design, which allows to tilt the screen aligned with the lens in both horizontal and vertical orientation, and see yourself, and have the range of motion to go with it. The X-T100 screen design was also pretty close to this, but we didn't see that design in the X-T200 as it moved to a traditional fully articulated screen. I think it's safe to say that we will not see that screen design again.