What is 400htz?

[admin_exported]

hey all

I just want to knowwhat 400htz means on some of the new top end lcds. I think sony and phillips so far have launched them!! So does this mean that 4 frames are put in for every actual 1 frame? 100htz was 1 extra frame 200htz was 2 extra frames(well sony anyway i think others use some kind of backlight trickery eh?) so is the 400htz involving some kind of trickery with the LED backlighting? as 4 frames seems an awful lot for the tv to do!!!

cheers

 

[Frank Harvey]

http://en.wikipedia.org/wiki/Refresh_rate

All you need to know, and quicker than me explaining

Personally, I'm against showing 24 frames per second material (movies) at anything oher than 24fps - it just looks wrong at 400, 60, or even 100Hz.

 

[TKratz]

But your link doesn't actually say anything about 400 Hz David.

Although I think I get your point. It is about increasing the refresh rate with or without interpolation involved.
I believe some TVs can run interpolation up to 200 Hz by introducing 3 artificial frames for each real frame, but I do not think this is the case for 400 Hz. Guess it will simply look too 'weird' running 7 artificial frames for each real one.

I can only agree on your point, that 24fps material should be displayed at 24fps!

 

[Anonymous]

i think the 400hz lcds are actual 200hz sets with a scanning backlight to double that to 400 hz in a kinda , pseudo scanning interpolation of the truth

, they are all at it ...

 

[aliEnRIK]

400Hz is bigger than 50, 100 and 200Hz and so the manufacturers want you to think that this is somehow better and so everyone should buy one

Personally id much rather they try to get the response times down to something like plasma quality

 

[TKratz]

To my knowledge scanning backlight is not normally considered part of the refresh rating, but I could be wrong.
It could also be that some manufacturers - in the battle for the superior specs - have started 'cheating' to artificially push the refresh rate up.

 

[TKratz]

aliEnRIK:

400Hz is bigger than 50, 100 and 200Hz and so the manufacturers want you to think that this is somehow better and so everyone should buy one

Personally id much rather they try to get the response times down to something like plasma quality

 

[Anonymous]

Is it not a number game again..as the 400hz is the refreshrate for when the tv is in 3d mode.As its dealing with double images.

 

[Anonymous]

no mate 200htz inserts 2 frames as 100 htz insers 1 extra frame! Otherwise it would be 300 htz

the 3d point sounds viable enough!

 

[TKratz]

Snakey:

no mate 200htz inserts 2 frames as 100 htz insers 1 extra frame! Otherwise it would be 300 htz

the 3d point sounds viable enough!

I think you got the math wrong. The TV signal is 50 Hz. At 100 Hz you need to double the frames adding 1 extra frame for each original one. At 200 Hz the frequence is 4 times higher which means you need to add 3 additional frames.

The 3D functionality could be a possibility, but I think it is more likely that the scanning backlight mentioned by Max, adding a black frame in between the rest could be what is labelled as 400 Hz.

 

[Anonymous]

i stand corrected mate

 

[bigboss]

I found this on Richer Sounds' website regarding an LG product:

Although different from 100Hz technology in not offering a true interpolation between frames, the 600Hz technology works by pulsing each frame 12 times, thereby upgrading to standard 50hz signal to an effective 600Hz one. If all this is double Dutch to you, then don't be concerned: suffice to say that the new technology gives the 42pq6000 a superb response with incredible realism and super-sharp tracking on fast moving motion such as sports events.

 

[aliEnRIK]

bigboss:
I found this on Richer Sounds' website regarding an LG product:

Although different from 100Hz technology in not offering a true interpolation between frames, the 600Hz technology works by pulsing each frame 12 times, thereby upgrading to standard 50hz signal to an effective 600Hz one. If all this is double Dutch to you, then don't be concerned: suffice to say that the new technology gives the 42pq6000 a superb response with incredible realism and super-sharp tracking on fast moving motion such as sports events.

Thats a plasma and its sub field drive, not screen refresh rate

 

[TKratz]

bigboss:

I found this on Richer Sounds' website regarding an LG product:

Although different from 100Hz technology in not offering a true interpolation between frames, the 600Hz technology works by pulsing each frame 12 times, thereby upgrading to standard 50hz signal to an effective 600Hz one. If all this is double Dutch to you, then don't be concerned: suffice to say that the new technology gives the 42pq6000 a superb response with incredible realism and super-sharp tracking on fast moving motion such as sports events.

Cheers Bigboss

The described mechanism is what Panasonic refers to as the 'subfield drive'. It is a special plasma feature which, as also mentioned by LG, is not be mixed up with the actual screen refresh rate. The screen refresh rate on plasma's is usually 100 Hz (either with interpolation or without).

The subfield drive is additional to the screen refresh rate and needed due to the nature of a plasma panel. The light from a plasma cell is only emitted for a few milliseconds, therefore the cell needs to repulse many times to maintain a picture. At the same time the colours are re-mixed/mastered by the subpixels at every pulse which is probably why this term is used.

 

[TKratz]

aliEnRIK:bigboss:

I found this on Richer Sounds' website regarding an LG product:

Although different from 100Hz technology in not offering a true interpolation between frames, the 600Hz technology works by pulsing each frame 12 times, thereby upgrading to standard 50hz signal to an effective 600Hz one. If all this is double Dutch to you, then don't be concerned: suffice to say that the new technology gives the 42pq6000 a superb response with incredible realism and super-sharp tracking on fast moving motion such as sports events.

Thats a plasma and its sub field drive, not screen refresh rate

I'm too late again!

Not easy trying to post while working, before you are finished the information is outdated.

 

[bigboss]

Oh....sorry, misread the question!!

Moral of the story: make an extra effort to read carefully especially when you're on night shifts!