Fuck if I know, I just believe everything I read.

I was suspicious this was oats studios latest thing and weird alien tech about to appear.

It does look like 60. Someone must have run it through a conversion (like a lot of tv's do by default)

It also looks 480p at best, with compression artifacts, so that's been upscaled too. Maybe taken from some other youtube channel. Also stencil buffers probably

uhd upscaling has become a bit of a thing for new trailers (I'm not a big fan of the new Marvel movies but the Civil War trailer looks especially good @60fps) and if you're so inclined a few movies like Pacific Rim, in which the 60fps get old shortly after the opening Kaiju fight. After a llittle while there's this weird effect on my brain which kinda feels similar to "uncanny valley" photorealism, like when you're playing some FPS and it's running at 60 but the barrage of flashy missiles and their occluded explosions are coming out at less than that.

In the YT description, the guy says he "did his best to restore and enhance the footage." A fairly in-depth blog post about the film (though not so much about the burning questions of FPS & resolution) here:

https://unwritten-record.blogs.archives.gov/2014/09/09/the-fir st-d-day-documentary/

Me, I just like seeing things play out for reals, like.