24 FPS used to be a reasonable sweet spot back when movies where slow-paced and high frame rates made for huge film reels (not to mention the lighting requirements for early color film).

Today there are no technical problems or impracticalities with high frame rates, and modern cinematography is hitting the limits of what you can do with 24 fps (and sometimes crossing them). 24 fps has become a local maximum because that's what we've done for decades, but it is also a blurry mess.

There literally are some impracticalities, though. For a Blu-ray player to support 60fps at 1080p, it's got to support level 4.2 of the AVC specification. Many (most?) players do not do this (and in fact some older models supported only 4.0), because it's more costly to include a decoding chip that can handle the bitrate needed for the uncompressed video stream.

Furthermore, much of home entertainment is streamed these days. I imagine introducing 60 fps on top of 4k would increase bandwidth requirements beyond what many consumers have access to. It may also be more than Netflix et al want to pay for, so one imagines they'll want to tack on a surcharge as they did for UHD.

The jump from HD to UHD quadruples the number of pixels, the jump from 24 fps to 60 fps only increases framerate by a factor of 2.5. Not to mention that the panels in any old HD TV will happily work with a 60 fps signal via HDMI, while the upgrade to UHD requires a new TV.

Yes, more frames means more data, but it creates fewer problems than the 4k/UHD upgrade everyone willingly goes through, while doing more to increase fidelity.

Right, but everyone agrees that UHD is an enormous improvement worth buying new hardware for. You said "there are no technical problems or impracticalities" to high frame rates, but 2.5 times the uncompressed bitrate is a technical problem, and so you have to have a situation where people are willing to pay for an upgrade. Most people seemingly don't care enough.

> the 4k/UHD upgrade everyone willingly goes through

I looked for 1080p screens when I last bought a TV and couldn't find any. 65", and wanting fairly quality, but no 4k sources so why do I need 4x the pixels? (Sadly, the week after I bought what I bought, I happened across some 65" new in box Plasma TVs at auction... Oh well)

Why is that an impracticality? TV productions are pretty much all still at 50/60Hz, they get syndicated to Netflix and streamed or sold on Blu-Ray and watched that way every day.

There's nothing new that has to be changed to support this, most of the content people are watching is already HFR.

This surprised me and so I wanted to check it out, but I think you're incorrect about this. I checked a number of shows shot in the last 15 years (The Expanse, The Wire, Schitt's Creek, Squid Game, Star Trek: Discovery, Foundation, New Girl, Community, Westworld), and every single one of them is either 24 fps or 23.976 fps in the versions available for streaming on the web.

Pretty much every TV documentary or larger production (e.g. Eurovision) is still 50/60Hz though.

It's only the narrative based shows that try to be "cinematic" which are at those low fps rates.

But the technology is there, it works just fine.

Large fast panning moves in a movie theater make my head spin, it's like a damn stroboscope. 24 FPS is not a sweet spot for everyone, it just happens to be what we got stuck with.

In many movies, I just can’t see motion and the blurry mess becomes entirely impossible to see. Which is why I end up reading plot summaries on wikipedia instead.

24fps is far too low.

The blurry mess of fast CGI is NOT down to the 24fps problem. As the action is so fast, it's faster to render complex scenes in lower detail CGI as the eye (mostly) can't see it.

However if you pause the action, you can clearly see where the rendering shortcuts have been made (The Transformers movies are a good example of this).

I'm not just talking about CGI, even e.g. taking my own a6300 and recording a moving scene has this effect (even with the 180° shutter rule).

It's just as choppy as 24Hz at 1/1600 shutter, but in traditional film, it's choppy and blurry due to the slow shutter, so I can barely see anything.

For quite se time I'd run upscalers to pre process all movies I was watching to 60Hz or 75Hz just because it was noticeably easier to watch.

The 24Hz/fps thing is a legacy from original film where it was the sweet spot that created the effect of a moving image without too much flicker, unfortunately you seem to be one of those people who are sensitive to this frame rate.

The argument is that the general populous are used to the 'film look' of 24fps, that anything else diminishes the impact of watching a film. Films that have tried high fps (The Hobbit for example) received negative reviews for picture quality; people just didn't like it.

Also, when increasing the framerate, you should try to stick to a multiple of 24 (i.e. 48, 72, 96) to prevent judder when the shot is panning a scene.

It was certainly good enough for millions of other people. What makes your eyes super sensitive to fps?

I don't know? Sometimes I also have issues where the perspective correction stops working and I see the image of each eye individually, with blind dot and perspective issues at the same time. But luckily only if I'm very tired.

Maybe something's wrong with my mind? But 24/25Hz, even with the correct shutter speed, is noticeably causing strain to process, while e.g. old school TV productions at 50Hz don't have that issue.

So you're able to interpret individual frame transitions at 24 frames a second? You've been unable to watch the vast majority of movies created in the last century as they strain your eyes? Maybe you need to get your bionic eye recalibrated?

Maybe gaming? When you play a lot of FPS in 120Hz then action scenes in the movies just look like blurred stuttering mess.

And stereoscopic 24fps look twice as bad.

Why would playing high frame rate games alter your vision? Is your brain reprogrammed when viewing image transitions at frame rates so high that they cant even be noticed.

Further research needed probably. But it doesn't seem to be far fetched to guess that what you do influences how you work.

I think you can notice high frame rates. Difference between 60 and 120 fps is striking. Even between 90 and 120. And everyone I was showing my phone that does 60, 90 or 120Hz could see it.

Conversely I don't see much difference between 120 and 240 fps.

Because it provides a different perspective, figuratively. I think that might also be a reason why HFR movies feel weird for some people, it's very much a comfort zone.