error getting 100HZ In my LCD

[smounche]

hello,

i don't know in which forum to write this message, so forgive me if i am in the wrong place.

i have an LG LCD 42LH70YR. i am trying to set the refresh rate at 100HZ. but it's only giving me up
to 60HZ.

i have win7 64bit. and a ATI 4890 HD as a graphic card.
using monster HDMI cable.

does someone can point me to any diraction.. i really tried everything..

Thanks.

[jagabo]

100 LCD HDTVs generally do not accept 100 Hz input. They take 50 Hz input and double the rate to 100 internally.

[edDV]

ditto Jagabo.

Are you sending video or computer desktop from the 4890? Which interconnect?

For video, "PAL" standards are limited to 25i/25p fps or 50p fps. These get frame interpolated or frame repeated in the TV to 100Hz.

If you send the desktop at 60Hz, frame processing is done in the display card.

[smounche]

hello edDV,

i am sending computer desktop + video from the 4890. the LCD is always connected to the computer

i know for a fact my model of the LCD can support 100HZ i DIDN'T just paid more $$$ in the store... trust me..

no matter what i do.. that stupid "refresh rate" will not go any further then 60HZ!!

what can i do ??

[MOVIEGEEK]

hello edDV,

i am sending computer desktop + video from the 4890. the LCD is always connected to the computer

i know for a fact my model of the LCD can support 100HZ i DIDN'T just paid more $$$ in the store... trust me..

no matter what i do.. that stupid "refresh rate" will not go any further then 60HZ!!

what can i do ??

That's because your videocard won't allow it, as was mentioned the tv will if it gets a 50Hz signal(eg tuner,DVD player).
I personally think these 100,120,240Hz hdtv's are a gimmick because you can't get true 24p playback. LG calls 24p "Cinema Mode".

[edDV]

hello edDV,

i am sending computer desktop + video from the 4890. the LCD is always connected to the computer

i know for a fact my model of the LCD can support 100HZ i DIDN'T just paid more $$$ in the store... trust me..

no matter what i do.. that stupid "refresh rate" will not go any further then 60HZ!!

what can i do ??

The 100Hz TV expects interlace video at 25Hz (50 fields per sec) or progressive video at 50 frames per second. This would come from a TV tuner. The TV then interpolates to 100 frames per second.

If you send it 60Hz frame rate from the computer, it reverts to 60Hz LCD computer monitor mode.

[aedipuss]

you don't set the refresh rate of the tv to anything but standard 50 htz pal or 60hz in the u.s. the higher refresh rate is turned on by the tv circuitry when it sees motion and you have turned on ME/MC (motion estimation/motion compensation) or whatever the option is called for your set. it's not really 100mhz as it can't stay at that rate.

[edDV]

I personally think these 100,120,240Hz hdtv's are a gimmick because you can't get true 24p playback. LG calls 24p "Cinema Mode".

"PAL" lacks a direct 24p support mode. Either 24p gets converted to 25P or the TV processes in "NTSC" mode.

"NTSC" HDTVs process 24P in one of the following ways.

1. Extract 23.976p from inverse telecine. You can't watch 23.976p directly without serious flicker. The TV will usually frame repeat frames 2 then 3 to 59.94 fps display.

2. A 120Hz TV will frame repeat 23.976 5x to 119.88 fps. This eliminates the 23232323 motion judder of "60Hz" HDTV sets. Advanced modes interpolate rather than repeat the four missing frames.

3. A 240Hz TV will frame repeat 23.976 10x to 239.77 fps. Advanced modes interpolate rather than repeat the nine missing frames.

I can see the case for judder reduction at 120Hz but am unconvinced 240Hz has benefit for film source.

For 59.94 non-film source (480i, 480p, 1080i or 720p), 120Hz must fill in one missing frame, 240Hz must add three.

[MOVIEGEEK]

I can see the case for judder reduction at 120Hz but am unconvinced 240Hz has benefit for film source.

I agree and most of the reviews for 240Hz HDTV's say to disable it if you watch 24p DVD or Blu-ray.

[edDV]

I can see the case for judder reduction at 120Hz but am unconvinced 240Hz has benefit for film source.

I agree and most of the reviews for 240Hz HDTV's say to disable it if you watch 24p DVD or Blu-ray.

Yes I left out 24p or 23.976p direct Blu-Ray modes but they get processed in the same way as inverse telecine.

[jagabo]

I agree and most of the reviews for 240Hz HDTV's say to disable it if you watch 24p DVD or Blu-ray.

There are two reasons for this. First, many film fans actually like the inherent jerkiness of 24 fps film. They don't like seeing smooth motion because it reminds them of TV, or even real life. Second, the motion interpolation used to synthesize in-between frames often makes mistakes. This leads to obvious distortions in some material. You still want to use the non motion compensated 120/240 Hz feature to eliminate the 3:2 or 6:4 judder.

[MOVIEGEEK]

OP,
This thread might help: http://thegreenbutton.com/forums/p/73709/360982.aspx

[smounche]

O.K
first thanks to everyone for replying..

so. i can't get it any more higher then what it is now? (60HZ)

[jagabo]

You might get smoother video playback of PAL material at 50 Hz.

[smounche]

hmm..
i don't understand something..
i only play MKV files (720p & 1080p) and right now. when i go to the properties of "screen resolution" in win 7. it's on 1920 x 1080
and the refresh rate is 60HZ

why did i payed so much money on a flat screen that support 100HZ and true cinema 24P. and a very good graphic card (ATI HD 4890) ??

[jagabo]

i only play MKV files (720p & 1080p) and right now. when i go to the properties of "screen resolution" in win 7. it's on 1920 x 1080
and the refresh rate is 60HZ

If your MKV files are 25 fps you'll probably get smoother playback at 50 Hz. Or 24 or 25 Hz.

why did i payed so much money on a flat screen that support 100HZ and true cinema 24P. and a very good graphic card (ATI HD 4890) ??

Why didn't you do a little research first? Traditionally, computer and TV refresh rates don't match.

[smounche]

so there is no possibility on earth to get 100HZ ?

[aedipuss]

it's just like all the other 100, 120, and 240 hz tv's, it only goes into that mode when it wants to, not something you can control, other than turning it off completely.

[jagabo]

it's just like all the other 100, 120, and 240 hz tv's, it only goes into that mode when it wants to

More to the point, they don't accept those refresh rates as inputs. Only output to the LCD panel.

[edDV]

so there is no possibility on earth to get 100HZ ?

Yes convert the video to a format the Samsung can decode (e.g. uncompressed 1920x1080i/25 HDMI or MPeg2 , see manual for list of formats) then the TV will process that to 100Hz. It will deal with any of the normal Blu-Ray player outputs (uncompressed 1080i/25, 1080p/24, 1080p/25, 720p/50...).

If you feed it a computer screen at 60Hz, the TV does nothing but emulate a computer monitor. The ATI card and/or software player are processing the video.

[smounche]

ahh.. i see...
so if i want to get the best quality. i need a good graphic card (like Nvidia GTX-295) ?

that card has pure HDMI input.. will i get better quality using that card ?

[jagabo]

ahh.. i see...
so if i want to get the best quality. i need a good graphic card (like Nvidia GTX-295) ?

that card has pure HDMI input.. will i get better quality using that card ?

No. That card will not be appreciably different from your ATI 4890.

[edDV]

Consider an external media player or a Blu-ray player. These will accept interlace or progressive video files and output uncompressed to the TV over HDMI.