No harm in Hz?
Remember the days when TV only meant one thing? After the advent of color, there really wasn’t much else to distinguish TV. We were blissfully unaware of anything beyond. With advances in video and broadcast technology, the idyllic existence slowly crumbled away. First came the concept of interlaced versus progressive. At first it took a bit to get one’s head wrapped around the concept. What do you mean the TV only draws half of the picture at a time? Then came the full flurry of ATSC. We went from TV to 480i/p, 576i/p, 720p, 1080i and finally 1080p. But wait there was more, there’s also 24/30/60 fps (and those peculiar 23.97/29.97/59.94 rates as well or 50 fps for our European readers). Did I mention there’s a difference between a frame and a field?
Still here? Given the near instantaneous proliferation of formats, is it any wonder that the average consumer can be so overwhelmed? The problem now is the industry seems to have moved beyond trying to educate the consumer to preying on their ignorance.
If one looks at the source material it simplifies matters somewhat. Source material is typically recorded at 24/30/60 interlaced or progressive frames or fields per second. Take a quick look at commercial broadcast and recording equipment. It becomes quickly apparent, that despite vast differences in interfaces and bit-rates, the basic frame rates don’t change. That camera broadcasting the Flames and Blackhawks is only capturing 29.97 frames per second (59.94 fields per second or 60i). So is there a real benefit to seeing the same frame as many as 8x (in the case of 480 Hz)? There certainly no interpolation to generate new frames of data so why?
That it’s largely a marketing (and partially a technical) benefit becomes apparent when one looks at the underlying screen technology most often touting ultra high refresh rates. Nearly without fail you will find high refresh rates being touted for one screen technology, liquid crystal display. The elevated refresh rates are used as a means to mitigate ghosting or motion blur. While vast improvements have been made in grey-to-gray (GtG) transition rates, the still lag those possible with plasma or CRTs. Some manufacturers are even inserting blank frames to boost contrast and/or address the ghosting. While one can’t argue with the novelty in addressing technical limitations, the problem arises with claims of smoother replay of fast moving objects on screen. One just needs to take a look at flyers from your favorite big-box electronics store.
Andrew Yang
May 15th, 2009 at 12:25 pm
So, how effective are these novel techniques at bringing LCD picture quality closer to that of a comparable plasma panel?
I must say, I’m a convert to plasma, and a little late to the game. I’m sad to see that just 18 months after buying my first plasma, the technology seems to be on it’s final legs.
As someone here pointed out in a previous blog, the main benefit of high refresh rates used to be to give a mulitple of 24, so that film-based material can be displayed without any 2:3 conversion (and concomitant judder). 3D video at home is another cool application made possible by high refresh rates. Are there others?
May 15th, 2009 at 3:51 pm
As Kieran says, one reason for higher refresh rates is to avoid interpolation errors (both 24 and 30fps can be refreshed at 120Hz without 2:3 conversion). I believe the LCD issue is because of response time lag in the panels. Like most things though, the implementation is key. I’ve seen displays with high refresh rates that looked great, and some not-so-great.
May 20th, 2009 at 9:35 am
I think using a high refresh rate to eliminate requirements for pull-down are fine, but the issue is the refresh rates aren’t necessarily used in that manner. As noted, some manufacturers are inserting blank frames so the pixels aren’t presented with a GtG situation, but a black (or white) to grey situation.
The issue isn’t the manner in which the manufacturers are trying to address the technical problem but rather presenting the solution as providing additional benefits, such as smoother presentation of fast motion on screen.
May 28th, 2009 at 12:54 pm
“The problem now is the industry seems to have moved beyond trying to educate the consumer to preying on their ignorance.” - This is all but TOO TRUE of a statement, as a 23-year-old up and comer I have witnessed the evolution of TV’s… My father is 66, so he’s seen it all… One of the Scariest trends was the FORCED move from Analog to Digital.. I honestly Hate digital, I mean at least with analog if the signal was weak you would be able to see a scrabbled picture and adjust the antenna to find a good signal, but now with the digital analog converter box if you don’t have that antenna in the exact position, you’re stuck with a screen that says “Weak Signal” or “No Signal”… And don’t even get me started on PIXELATION… I HATE that too… We’re in an economic recession and the last thing we should be conserned about is how refined we can make our TV’s so we can “See the Blades of Grass on the Fields of the Game” or whatever ad slogan the companies are using.
One example is the Super Bowl commercial Visio did, where it blatently told the viewer to look at the Logo on their TV and if it didn’t say “Visio” then they weren’t watching the best picture quality out there… they neglected to give any specifics or examples of why they were the best, just simply “Visio is the best”… I’m paraphrasing with the quotes, but I think you get the idea….
Let’s go back to the good old days with turn nobs and where you actually had to get up to change the channel…. As my father once told me, something he was told by an old news Anchor, the job of a broadcaster is merely to “Fill the blank space between commercials”