4K 60 Hz TV sets and 24 Hz films

[PCFan]

I was wondering TV sets with 4k 60 Hz HDMI outputs handle films filmed at 24 hz at 4k? Do they do 3:2 pulldown for 24 Hz signals or do they lower the refresh rate to 48 Hz or 24 Hz and not do 3:2 pulldown? What about those sets that say effective refresh rate of 120 Hz but in the specs says that HDMI inputs are 4K at 30 Hz or 4k at 60 Hz?

[Opips3]

Originally Posted by PCFan

I was wondering TV sets with 4k 60 Hz HDMI outputs handle films filmed at 24 hz at 4k? Do they do 3:2 pulldown for 24 Hz signals or do they lower the refresh rate to 48 Hz or 24 Hz and not do 3:2 pulldown? What about those sets that say effective refresh rate of 120 Hz but in the specs says that HDMI inputs are 4K at 30 Hz or 4k at 60 Hz?

I was read it I can't find website information.

- 4K at 30fps and 4:4:4

- 4K at 60fps and 4:2:0

Only 30 frame per speeds. And in future 60fps. Stay 3:2 pull down.

[PCFan]

So then it's a trade off then? Either watch a regular blu-ray at 1080p at 24 Hz without TV doing 3:2 pulldown or watch a 4k bluray at 24 Hz but then the TV does 3:2 pulldown? So on a 4K TV set that advertises 120 Hz refresh rate, that's only for 1080P signals?

[Kris Deering]

A 120 Hz refresh rate means that all inputs are shown at 120 Hz. So if the input to the TV is 24p, what you probably get is each frame repeated five times, so 5-5-5-5-5. If you are inputting 60p, it is 2-2-2-2-2-2-2. 3:2 pull down is typically a function of a player. So if you have a player that you have set to output 60p, but the source your playing is 24p, 3-2 pulldown is applied to the output to convert the 24p material to 60p. The display is likely taking that 60p and doing the 2-2 repeat to match its 120 Hz refresh rate.

And let's not even get into inverse telecine or frame interpolation. That is another can of worms altogether.

Clear as mud right!

[Geoff D]

Some sets have a reverse pulldown feature, Sony's is called True Cinema and it's excellent at restoring 24fps cadence to 60Hz film material. It's not so much of an issue with 24fps sources, natch, but for older Blu-rays or DVDs it's a life-saver.