Let's talk a bit about the three main mediums by which sound and pictures are delivered - there's the world of film which gave us "motion pictures," there's analog video which gave us television, and of course, there's the digital realm of computers.  All three give us sound and pictures, but from a technical point of view, all three do it in very different ways.  One of the things that I find most interesting about the current state of digital video is that it, because it is the newest technology of the bunch, represents this really interesting amalgamation of the best standards and technologies that has been inherited from all three realms.  So in the next series of programs, we're going to be talking about this convergence of technologies and put it into context, so that we can understand better why things are the way they currently are - and to do that, we're going to start with a bit of a history lesson.

transcript:

Back in the 1890's there was this Scottish guy named William Kennedy Laurie Dickson, and he was working for this guy named Thomas Edison, and they were working on this thing called the kinetoscope, which was sort of a proto movie projector of the time.  The kinetoscope used a 19mm wide piece of film with one set of perfs on the side, the perfs are those little holes that keep the film tracking along, and it was a bit too jittery for Dickson's taste, so he called up his buddy George Eastman who had just released this new film called Kodak. It was 70mm wide and he said, "Dude," (or the 1890's equivalent), "Cut that 70mm sheet film in half, put perfs on both sides," and that was the birth of 35mm film format.

Now I know there are some film geeks out there who are going to write to me and say, "Hey, there's a different story about 35."  Yeah, you know, the early history of photography for some reason is full of conflicting stories, I researched this one, I'm going with it, but it doesn't matter.

What matters is that you take away the width of the perfs and you're left with about 24mm in the horizontal dimension for imaging.  Now, Dickson established that four perfs would represent the vertical dimension of the frame, and that comes out to about 18mm, and indeed that did become the standard frame size for the silent movie era.

Now, for our purposes we don't really even care about 24 and 18, what we care about is the mathematical relationship between the two, which comes out to about 1.3, which is the same way of saying 4 units wide by three units high, or 4:3 - and this is what we call the aspect ratio, and you gotta remember this term because we're going to be talking about it forever.

Now you might be thinking to yourself, "Gee, this shape seems somewhat familiar to me."  Well, we've already talked about it being used in the silent movie era.  When television was established, it too used the 4:3 aspect ratio as the standard for its screen. Fast forward some 40 years or so and the CRTs on personal computers also used this same aspect screen, and look, even in 2005 when Apple released its 5th generation iPod, its LCD screen had these same proportions.

Now frankly I was a bit surprised when Apple released its first iPod with video having a 4:3 screen, but then in thinking about the evolution of that particular product line at that particular time, it started to make sense. Coming up in Program 3, though, we're going to talk about the other important aspect ratio in digital video, and discuss the many different meanings of the word "widescreen."

notes:

Thanks to the kind folks at the George Eastman House in Rochester, NY who helped me clarify the 35mm historical reference when I visited them this winter.  I highly recommend a visit.

Any video geek worth his/her salt knows that the “real” video iPod will have a 16:9 display, but the tooling, chipsets, display and user-interface elements were already in place in late 2005 to easily release a video-enabled 4:3 iPod right away.