Setting the loop size is incorrect in this video. You are meant to pull all of the slack film towards the white line and make sure it then falls between it. In this video he seems to be trying to make the loop size even on both sides of the gate which is incorrect.
That's the way it is done, if you want a training aid, you can work with Night vision goggles and the IR illuminator (movie film doesn't respond to IR). I got this from a pro still photographer that teaches how to process large format in a darkroom.
Yes, use a changing tent, bag or a dark room (this can be a room in your house if you can make sure the room stays dark when you're loading the film into the feed side of the magazine.
Film negative must be either scanned or telecine'd for conversion to digital. Lots of companies can do it in North America, the price varies depending on the method of color correction and resolution chosen. If you're rich, you could buy a scanner yourself. Blackmagic makes one: www.blackmagicdesign.com/ca/products/cintel
When loading these (or many Arri mags,) use the white line to set your loop. Going past the line at all is not recommended. As you see in this video, he goes past the line by a couple of perfs and the loop size is off. Also, if you wait until the "camera tells you if the loop size is good", you'll just embarrass yourself. Get it right when loading the mags! And yes, lot's of productions still shoot on film! Baby Driver, Hidden Figures, etc.
+Đorđe Gajanin The Walking Dead is shot on 16mm film. A decent amount of movies & TV shows are shot on film. The problem is that shooting on film is more expensive than digital, and requires traditional care & hurdles on-set compared to the more "up & go" nature of shooting digital. So actually shooting film is more of a premium thing when you have a huge budget to swing around.
