First off: Paul, 24hz is not the correct term. The correct term is 24P, as in progressive. What good does frequency (hz) do you when you could also mean field, split fields, or progressive. I know that videophiles like to talk hz but its just not accurate. What is stored on digital tape (VTRs) could be P (progressive), Psf (Progressive, split field), or interlaced (with or without pulldown). Even when you talk about processing you should be talking P, Psf, or i, not hz. Talking about the frequency at which you process doesn't tell you anything about what you are processing whereas when someone says 24P I know both the frequency (24hz) and the fact that the frames are fully progressive. People in the industry used to talk about F vs f (as in frame vs field) but the old timers could not get themselves to write an upper case F so everyone gave up and started talking P for progressive. Keep in mind that this discussion goes back to the 70s at the BBC.
Film is shot in 24p for a very good reason, it is a frame rate which allows you to enjoy the film (enough refresh) without asking you to believe completely in the production (it isn't TOO real). Because of the low refresh rate you are know (your brain knows) it is film and you automatically drop into a more relaxed state (you have been programmed to do so). Just as blair witch used its video recording at higher frame rates to add more realism, 24 frame film allows you to intrinsically understand that what you are watching is entertainment, not reality so movie productions can get away with murder, fantasy, and push the limits of believability without asking you to fully commit yourself. The film studios have done many studies at 48hz, 60hz, and 72hz and what happened is people enjoyed the film LESS. Most people felt that the film took on a documentary feel, that what they were watching was closer to reality.. horror scenes took on a new level of believability causing the audience to become very engaged, the extra reality scared the crap out of people.
The argument for 24P in HDTV is simple, it allows you to recover the raw frame rate and then using integer multiples, create higher refresh rates without adding a significant amount of frame judder or field artifacts. You can easily go from 24P to 72P for instance by simply repeating every frame this allows you to display at 72Hz on a monitor with few artifacts. Every other cadence requires pull up or down or field repeats which creates visible artifacts. This BTW is exactly how a film projector works, the shutter on a film projector opens and closes 2 or more popularly 3 times for every frame creating a 72hz persistance on the film screen. http://en.wikipedia.org/wiki/Movie_projector
While I don't entirely disagree with you, I'm guessing that terms like "24p" and "60p" are just interchangeable shorthand for "1080p/24" amd "1080p/60," as I've never seen the "p" applied to both numbers when written like this. Also, "Resolution setting is 1080p/24 Hz" is what pops up on my A20 right after the HD DVD logo appears. Toshiba themselves use "Hz" when writing about the different speeds of their LCDs, as seen in the paragraph below:
"A standard LCD TV typically has a frame rate of 60 frames per second, or 60Hz. To avoid possible motion blur with fast motion video, ClearFrame doubles that frame rate to 120 frames per second, or 120 Hz. While there are many possible methods for creating the additional 60 frames, ClearFrame utilizes superior Motion Vector Frame Interpolation (MVFI) technology. MVFI analyzes Frame A and Frame B and creates a new Frame A+B. By evaluating the speed and direction of multiple picture elements within the frames, this advanced system virtually eliminates motion blur without decreasing image brightness or adding flicker."
And, in their FAQ section:
"Q1. What does this update do?
A1. This firmware update adds support for 1080p/24Hz output to the HD-A20 and HD-XA2 players."
I'm sure any videophiles or engineering/AV experts reading this post will have something to add, but I'm only repeating what I've seen on Toshiba's site as well as countless others.
Reader Comments (Page 1 of 1)
earthling @ Oct 1st 2007 8:59PM
First off: Paul, 24hz is not the correct term. The correct term is 24P, as in progressive. What good does frequency (hz) do you when you could also mean field, split fields, or progressive. I know that videophiles like to talk hz but its just not accurate. What is stored on digital tape (VTRs) could be P (progressive), Psf (Progressive, split field), or interlaced (with or without pulldown). Even when you talk about processing you should be talking P, Psf, or i, not hz. Talking about the frequency at which you process doesn't tell you anything about what you are processing whereas when someone says 24P I know both the frequency (24hz) and the fact that the frames are fully progressive. People in the industry used to talk about F vs f (as in frame vs field) but the old timers could not get themselves to write an upper case F so everyone gave up and started talking P for progressive. Keep in mind that this discussion goes back to the 70s at the BBC.
Film is shot in 24p for a very good reason, it is a frame rate which allows you to enjoy the film (enough refresh) without asking you to believe completely in the production (it isn't TOO real). Because of the low refresh rate you are know (your brain knows) it is film and you automatically drop into a more relaxed state (you have been programmed to do so). Just as blair witch used its video recording at higher frame rates to add more realism, 24 frame film allows you to intrinsically understand that what you are watching is entertainment, not reality so movie productions can get away with murder, fantasy, and push the limits of believability without asking you to fully commit yourself. The film studios have done many studies at 48hz, 60hz, and 72hz and what happened is people enjoyed the film LESS. Most people felt that the film took on a documentary feel, that what they were watching was closer to reality.. horror scenes took on a new level of believability causing the audience to become very engaged, the extra reality scared the crap out of people.
The argument for 24P in HDTV is simple, it allows you to recover the raw frame rate and then using integer multiples, create higher refresh rates without adding a significant amount of frame judder or field artifacts. You can easily go from 24P to 72P for instance by simply repeating every frame this allows you to display at 72Hz on a monitor with few artifacts. Every other cadence requires pull up or down or field repeats which creates visible artifacts. This BTW is exactly how a film projector works, the shutter on a film projector opens and closes 2 or more popularly 3 times for every frame creating a 72hz persistance on the film screen. http://en.wikipedia.org/wiki/Movie_projector
Paul Fernandez @ Oct 2nd 2007 8:08AM
earthling:
While I don't entirely disagree with you, I'm guessing that terms like "24p" and "60p" are just interchangeable shorthand for "1080p/24" amd "1080p/60," as I've never seen the "p" applied to both numbers when written like this. Also, "Resolution setting is 1080p/24 Hz" is what pops up on my A20 right after the HD DVD logo appears. Toshiba themselves use "Hz" when writing about the different speeds of their LCDs, as seen in the paragraph below:
"A standard LCD TV typically has a frame rate of 60 frames per second, or 60Hz. To avoid possible motion blur with fast motion video, ClearFrame doubles that frame rate to 120 frames per second, or 120 Hz. While there are many possible methods for creating the additional 60 frames, ClearFrame utilizes superior Motion Vector Frame Interpolation (MVFI) technology. MVFI analyzes Frame A and Frame B and creates a new Frame A+B. By evaluating the speed and direction of multiple picture elements within the frames, this advanced system virtually eliminates motion blur without decreasing image brightness or adding flicker."
And, in their FAQ section:
"Q1. What does this update do?
A1. This firmware update adds support for 1080p/24Hz output to the HD-A20 and HD-XA2 players."
I'm sure any videophiles or engineering/AV experts reading this post will have something to add, but I'm only repeating what I've seen on Toshiba's site as well as countless others.