24 FPS Input Displayed At ???

[admin_exported]

Hi, I am looking at upgrading my system after three years and looking into the latest and greatest. Currently upgraded to DVDO VP 30 Scaler to map the screen pixel by pixel with SDI input and ABT deinterlacer, Sky Plus modified with SDI output. But it seems the only Supplier of a screen that DISPLAYS 24 FPS is the Pioneer. I have spoken (so far) to the technical depts at Samsung and Panasonic and all their screens all use pull down for either 50 or 60 hertz for the display. They The only company so far to confirm TRUE 24 FPS is Pioneer who multilpy the frame rate to 72 FPS. I believe the magazine reviews should say if the screens they are reviewing ACCEPT and DISPLAY 24 FPS or just Accept 24 FPS and convert it to something else. I have spoken to Pioneer on this topic at length and they are in the process of using a logo to ensure that purchasers understand the difference. If I want High Def a display it must be 1920 by 1080 anything else is not high def. -- Kevin High Def

 

[Mr.H]

You have brought up a good point - it is always important to check if a display that "accepts" 24 fps will actually go on to display it at 24 fps. Some older Toshiba models for example, accepted 24 fps, but used internal "pull down" processing to display 25 fps instead.

However, the people you spoke to at Samsung are quite wrong - several of their models will accept 24 fps signals in their so-called "just scan" mode, which applies no picture processing at all - the frame rate is un-altered and the picture is mapped pixel-for-pixel.

In addition, I believe most of the latest Sony and Toshiba displays will also handle 24 fps properly. The marketing departments of those companies like to peddle some nonsense about it being increased to 120 fps by "repeating the same frame five times in a row", but showing frame "A" five times in a row for 1/120 of a second each is exactly the same as showing frame "A" once for 1/24 of a second.

You will note that needing to check that a display will really display at 24 fps, but even the "technical" departments of some manufacturers not knowing the correct answer presents somewhat of a problem.

The AVforums (www. avforums . com) are a good place to go to try and find out the truth.

 

[Anonymous]

All of the latest spec sheets differentiate those screens that just accept 24fps and use pulldown to 50 or 60 Hz -- and those screens that fully support 24fps, typically in this case 5:5 pulldown at 120hz. From what i can see there is only the z line of toshiba's that fully support it

 

[Anonymous]

re: the above post i was referring to Toshiba LCD TV's

 

[Anonymous]

Hi, I have spoken to the following technical departments. Samsung, Panasonic, Sharp and Hitachi. They have told me catagorically they their screens DO NOT display at 24fps or at 48fps 72fps 96fps or 120 fps. They all scale pull down to either 50 or 60 hertz. I clearly asked if they understood the question I was asking them. The only company thus far I have found that can display 24 fps at true 1080P is some of the Sony range they display multiply at 24fps to get to 96 fps. My view is that if a company does not understand the product they are selling they should sack the sales team and the technicians and find someone that can sell and advise on their products. If I am prepared to spend a reasonable amount of money like many other people on this forum, why should I have to put up with such incompetence.

 

[Anonymous]

Does anyone have any idea why these companies (Panasonic, etc.) make their tvs capable of accepting 24Hz, then go to the trouble of having the tvs convert the framerate to 50 or 60Hz? Surely this is a much more difficult process than simply doing a 3:3 or 5:5? Also, does it not kind of defeat the object of being able to accept 24Hz?

 

[Anonymous]

The reason is that most TV screens either operate at 50 or 60hz, or multiples of 25 or 50....... the problem is that these are not multiples of 24 which is the problem.....so some convertion is required.

Some of the newer ones operate at 100/120 hz ...120 is a multiple of 24 and therefore 5:5 is possible.

The only spec sheets i have seen so far that state these are the Toshiba 37Z3030D and the 42Z3030D

 

[Anonymous]

Yes but why do these tvs have to run at 50 or 60Hz? Surely it is easier (and cheaper) to switch between rates of Hz, than to implement a processing power hungry frame-rate conversion? I know that the Pioneers which are capable of doing this are expensive but most affordable tvs too can switch Hz between 50 and 60, so why not to 48 or 96 or whatever? Panasonic went to the trouble of building their tvs to do 3:2 conversions when it would surely take much less effort (and more relevantly less money) to simply enable the tv to switch Hz (like they already do between 50 and 60), between say, 50, 60 and 72? Surely this is not a case of the Pioneers being able to have this feature because they cost more, because as I have just said, making a tv that can switch to different rates of Hz is not a difficult or costly job. It is probably a lot more costly to develop and implement the algorithms that are needed to do framerate conversions, than to simply shift the rate of Hz. So why don't they just switch the rate of Hz?

 

[Mr.H]

[quote user="BenjaminHart"]
Yes but why do these tvs have to run at 50 or 60Hz? Surely it is easier (and cheaper) to switch between rates of Hz, than to implement a processing power hungry frame-rate conversion? I know that the Pioneers which are capable of doing this are expensive but most affordable tvs too can switch Hz between 50 and 60, so why not to 48 or 96 or whatever? Panasonic went to the trouble of building their tvs to do 3:2 conversions when it would surely take much less effort (and more relevantly less money) to simply enable the tv to switch Hz (like they already do between 50 and 60), between say, 50, 60 and 72? Surely this is not a case of the Pioneers being able to have this feature because they cost more, because as I have just said, making a tv that can switch to different rates of Hz is not a difficult or costly job. It is probably a lot more costly to develop and implement the algorithms that are needed to do framerate conversions, than to simply shift the rate of Hz. So why don't they just switch the rate of Hz?
[/quote]

Good question! 50 and 60 Hz are clearly hang-overs from the days of CRT. When it comes to an LCD display, the panel itself is capable of running at any frame rate (up to a maximum limit imposed by the response time of the pixels). You could run them at 0.5 Hz if you really wanted to. The backlight is on all the time, and the LCD crystals stay where you put them (they do not need "refreshing").

The answer to the question must be that it is due to the driving electronics being designed to deal with traditional PAL and NTSC signals. It is very frustrating.

 

[Anonymous]

You are correct the 50 hertz relates to the 50hz mains frequency in the UK and the 60hz to mains frequency in the states. In the old days this gave the manufacturers a good trigger to start the frame. Th old methods die off slowly. I agree it is possible to run the screen at 0.5, . The problem can resolved by just setting the frame rate to 48, 72, 96 or like toshiba 120, but you have to get engineers around a table to say thats what we will do. I have already emailed Sony to confirm the conversation I had with then that "24 True Cinema" use 96 frames per.second when the input is being fed 24fps. Their latest Product Catalogue Autumn/ winter 2007-2008 does not say exactly what "24True Cinema" does. THis may be a real pedantic point but the screens are expensive and will last a minimum of 5 years. I and I am sure you do not want to be in the position in say 2 years time when the Blu Ray / HDD fight has finished. That of course you need to able to display 24 FPS dont you!!

Sony have now confirmed in writing that KDL 46X3000 displays 24 FPS as 96 FPS. Shall we we what other manufacturers will confirm this in writing.?????