This month’s column is a continuation of my last Video Assist column. In case you missed it, I was talking about how I’ve often been asked where to find accurate information in our industry. I gave an example from an online article that otherwise had a lot of good (and accurate) information. The article stated (and I’m paraphrasing), “NTSC is 29.97 because they use the extra three frames to store the color information.” While I don’t want to get into a detailed explanation of the history of NTSC and delve into terms like “subcarrier” and “compatible color,” a little math will quickly show an error.
Simply put, if “they” used three extra frames, it doesn’t add up; 30 minus 29.97 gives you .03, which is 300ths of a second. If you need to grab three frames for storing color, you’d need three 30ths of a second. Using that logic, instead of having 29.97, it should be 27.00.
Beyond the math error, think about how difficult editing or even switching between cameras in a live show would be if you end up cutting off the three color frames or using color frames from a previous scene.
But this isn’t about “I’m right, and they’re wrong”; it’s about errors creeping into information that we use every day. The rest of the article I referred to had a lot of great information, so I don’t want to throw the baby out with the bath water. Do “three extra frames” really matter in day-to-day production? Probably not, but similar errors can matter. Since it was introduced in 2008, I’ve always been curious about the engineer (or engineers) who decided that 30 frames per second was the correct frame rate for the Canon EOS 5D Mark II. While this has since been fixed with a firmware upgrade, I wonder whether that decision came from someone saying “30” when they meant “29.97”?
But we aren’t designing hardware, so you still might ask, “Does this really matter?” Well, if you had to deal with the footage coming from the 5D, you’d easily say yes. You might not be designing hardware, but you’re using it. And you’re using more and more software on different devices.
Software is sometimes written by people with great knowledge about our industry and sometimes it’s not.
I see more apps on various devices like phones and tablets. Some of the same errors that crept into our world when we transitioned from dedicated hardware-based systems to software-based systems are now creeping into apps.