4K TV refesh rates

[neorichieb1971]

Just a quick question really.

If I use 50hz and 60hz sources would a 900hz TV be better than a 1000hz TV?

Since 50 and 60 go directly into 900 and not a 1000 I just wondered if the extra expense on 1000hz technology is worth it.

Also, how much truth is in the specifications?


Thanks for your input.

[ZellSF]

Those are entirely bullshit marketing numbers.

I'm not an expert, but I think anyone who is would want something more specific about what you are comparing.

[blizzz]

If you want to play on such a screen you would turn all the frame interpolation crap off. So it really doesn't matter.

[neorichieb1971]

Well regardless of the BS there must be some difference between the 900hz and 1000hz models.

I understand the companies feel the biggest number wins.

http://www.currys.co.uk/gbuk/tv-dvd-blu ... 4-pdt.html - 1000hz

http://www.currys.co.uk/gbuk/tv-dvd-blu ... 5-pdt.html - 900hz


£1649 each. Tell me more.

[Ed Oscuro]

blizz is completely right, it's about computer software fakery. However, there's a bit more to the story.

So, here's how it works on a few idealized displays:

*100Hz - this started appearing in later CRT TVs to help eliminate picture flicker. The technique is essentially the same as a movie theater film projector displaying the same frame multiple times to eliminate the appearance of flicker. But like film, its source framerate is still 50Hz, and the characteristics of the source aren't changed, just the technical details of how they're displayed. For film, showing the same frame 3 times doesn't mean we get 72fps.
*For a 100Hz or 200Hz HDTV without motion interpolation, the concept is the same. Regular consumer HDTVs still do NOT display 100Hz or 200Hz content (or 120Hz or 240Hz in NTSC areas); but they are more flexible in showing some different frame rate material less than 50 or 60Hz. The extra real frames are used for pulldown (i.e., a NTSC TV with a 240Hz framerate can display 60HZ OTA broadcasts, and it can display 24fps film sources by displaying each frame ten times, all on the same underlying panel). You'll note that the big numbers are typically a multiple of 24Hz, just so the same panel can accommodate both film and local TV programming. There's really no other benefit to it; the panels are still as slow as those on 50/60Hz only sets, so you're not even getting faster frame transitions - when dealing with 24Hz film it's not as if you're going to notice it more than with 50Hz material, of course.
*For a 1000Hz TV or whatever, the number is referring to the TV's motion interpolation software - using its CPU to generate a fake frame, generally to make things (i.e., cars, sport balls, and players) seem to track across the screen more smoothly...than they actually do in the original material. Confusingly, the set can't possibly show 1000 frames in a second, so the number apparently comes from some back of the napkin calculation about how "good" the motion interpolation software is...maybe, maybe not.
*Finally, what WILL make a difference to viewing quality is black frame insertion or, better yet, backlight strobing, though this stuff is still developing. This should work even with slower frame rate stuff and it even can help cover up for slower pixel transitions. Also, true variable framerate computer monitors are appearing thanks to FreeSync and G-SYNC, but it's not clear to me how that will impact HDTVs for TV and movies, let alone whether it will stop the marketing juggernauts.
*Something else that would be good would be faster material, but you can't get it for most any HDTV yet, only computer monitors. 4K TVs are 60Hz at best, and many game consoles struggle to hit 30Hz. FreeSync is the more appropriate technology for consoles. Without support for faster source material, all the faster TVs will be good for is displaying both movies and TV on the same set. That's it - there's really no other benefit when the source is still 24, 50, or 60Hz.

What TV manufacturers don't make clear is what the "real" framerate of the TV is (not the framerate of the material it's showing or that it can accept, or the interpolation figure - but the number of individual frames it can display), and when the numbers are just based on motion interpolation, i.e. fake computer generated frames.

Rtings to the rescue, then:
http://www.rtings.com/info/fake-refresh ... -trumotion

Since these fake refresh numbers are invented by each company, they are also all different from each other, which makes direct comparison across brands impossible for those who don’t know the conversion to real refresh rates

A couple notes: Rtings' listed numbers are different from yours, i.e. they show 900 and 1440, not 900 and 1000. I do think that the "Motion Rate" mentioned in your links is the same thing as Sony Motion Flow, and the difference should be down to the markets needing different multipliers due to 60Hz vs 50Hz native.

Incidentally, the longer comment in the Q&A section has some important information.