petermc Not a stupid question!
Scaling: This term has a lot of interpretations, so for the sake of our discussion lets say "scaling" is "inanimate objects with known and agreed upon dimensions appear to be visually correct with relation to their proximity to the camera, ie. me, in a VR video." To that I'd say most are ok nowadays, but outside of len differences there is a lot of room to mess up in the editing bay. Most editors handle VR footage in MistikaVR, that has its own lens preset for the K2 Pro, an industry-standard VR180 camera today. After the preset is applied, the stereo and focal length still need to be messed for each clip; Here's a good YouTube video of this process
When aligning stereo images, difference between L & R is known as "stereo disparity," which affects scale via "parallax", so if an editor is careless then they can affect the "scale" of things. Here's a good video explaining parallax.
Another factor to consider is our expectation of a performer's size. Some girls are taller/shorter in person than they appear in 2D; I too have been surprised at the size of some performers IRL.
Distance: Every body is different. We work with a handful of male talent for POV scenes, but each has their own individual torso lengths, body landmarks, etc., so I imagine other shooters have devised their own ways to try and address this issue as well. I have a guide I call the "dick stick" which measures camera distance from base of performer's penis to the lens; I try to keep it around 21-ish inches as I've found that to be pretty average and is in the focus sweet-spot for my camera. Again, even if my measurements perfect, it doesn't matter if an editor messes with the stereo incorrectly.
Another important fact regarding distance is that there is no live headset preview on any industry-standard cameras, which seems almost like a no-brainer, but sadly here we are. So on the K2, all I get to see is a live preview of the fisheye image and have to approximate if my angle is correct based off of measurements taken before rolling. With a little luck, experience, & intuition, I can only do my best and hope that it was filmed the way I had intended it and, if it's a scene that I don't personally edit, is handled with care by a well-seasoned VR180 editor.
