We have two CRTs on which “we” (meaning the kids) watch Netflix DVDs and local broadcast TV sports. The DVD display is a 15 yo SONY CRT. It will still be running when all of our neighbor’s LCDs need their light tubes replaced. The television is a 9” “portable” CRT that, I think, has color. The “TV” uses a “free” converter box and our rabbit ears.
So this story on how those newfangled HD TVs intersect with the complexities of capturing motion in analog film and digital sensors, both converted in various ways to travel through various digital to analog transformations (including some back and forth in fiber optic backbones) and then to photons (themselves both digital and analog) and then to quantum sensors (retinal neuron photo receptors) and to analog signals (brain) and then to perception and meaning (?) …
Well, it’s all a voyage to a foreign and exotic world that, one day, when the children are old enough to buy their own TV, we might visit.
Read both the story and the comments, I’ve excerpted enough here to show why this is academically intriguing …
Help Key: Why 120Hz looks “weird”
John Biggs
I’ve been testing an HD projector here at the house and, in its initial, out-of-the-box setting we found that the picture was ridiculously “sharp.” The picture, I suppose, looked like an old Dr. Who episode where the action on screen is smoother than the background, creating a jarring disparity when watching movies with lots of movement. It’s sometimes called the “Soap Opera Effect.” We decided to do a little digging to figure out why.
Most film is recorded at 24 frames per second, but your LCD TV probably either displays at 60 fps or 120 hz (hertz is just a measurement of frequency per second). There are three main ways to cope with this…
Paul Spurrier
… The problem with motion interpolation is that it is having to create new frames that weren’t on the original film..
… Your TV is having to do this in 1/24 of a second.
Which is impossible.
So it cheats. It uses warping and other motion compensaton/interpolation techniques to create inbetween frames that sort of fool the eye…
…And not surprisingly it looks weird…
… Nowadays, as more movies are shot digitally, filmmakers are trying hard to work out what it is that makes a movie looks like a movie. Then they’re trying to alter the digital picture to replicate that look…
… Gamma. It’s complicated but basically film and video react to light in different ways. Film still sees more detail in the brightest and darkest parts of the picture and sees colour in a different way. Another thing that filmmakers do to make digital images look like film is to alter the gamma, either in camera or in post-production…
… Frame-rate. To bring this back to the original subject, traditionally the biggest give away that one is watching a video-originated image and not film is the frame rate. In the US, video cameras shoot 60 frames a second. They cheat a bit to do this…
… Nowadays, we can set digital cameras to not do this. We change them to film in what’s known as a ‘progressive’ mode, which shoots full 24 frames a second.
In the old days, filmmakers used to go to great lengths to get rid of this interlacing….
… It was clear that the higher frame-rate was a give-away that the image had been shot on video not on film. So even if we degraded the picture somewhat by throwing out half the data, it still sort of looked ‘better’.
… audiences react differently to video and film. They don’t know they’re doing it, and it’s working almost entirely on a subconscious level, but when someone thinks they’re watching a movie, their mindset is that this is something more special, bigger budget, more worthy of their attention.
So imagine the frustration of filmmakers when new TVs undo all of the work we have put in to making something look like film and make it look indeed like a ’soap opera’…
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