Class Act: Learning in HD
Despite the move towards HD for online video, there are still use cases where SD is the best fit
2010 has definitely become the year of high definition. The capability to shoot HD video now comes in cell phones, pocket cameras, DSLRs, and plain old camcorders. For the educator, the question is not whether you should shoot HD video. Instead, the question should be: When is HD the best choice?
Even though a palm-sized HD camcorder costs less than $200, it doesn't mean that shooting HD comes without cost. First off, the H.264 and AVCHD codecs these cameras use don't always easily import into your favorite editing application. Even if you can drag footage right into your timeline, once you start cutting and adding transitions and titles, your render times can skyrocket. Rendering out your final HD video adds even more time.
Let's face it, not every project calls for the increased resolution and detail of HD. Talking heads and lectures constitute one class of videos that rarely benefit from HD. Lighting is very important for making human subjects look their best, and it's the rare lecture hall that has flattering lighting. Adding HD to the mix will only make poor lighting look worse, in which case, your lecturer will not be thanking you. You're best off shooting in standard definition-even with an HD camcorder-and saving the disc space and rendering time.
Furthermore, not all HD cameras are created equal. True, I've seen some spectacular HD video coaxed out of iPhones and Flip cameras. But these were executed by experienced videographers bringing all their ingenuity to bear in extracting the very last drop of performance from these inexpensive tools.
But there are many situations where the increased detail of HD will enhance a project. The sciences are a realm where you often can put a camera in places where practicality and safety wouldn't allow a student to be. A good quality zoom lens can let a camcorder capture a volatile chemical reaction more clearly than anyone could view it from a safe distance.
HD is also well-suited to the visual arts. Again, it can be impractical to let a lecture hall full of students get close enough to get a good look at a sculpture or painting. More to the point, a teacher may be able to take some video of a performance or other work thousands of miles away from the classroom. In this case, HD can make the experience more engaging and dynamic for the student.
Of course, none of this matters if you deliver the video to students in old-school resolutions such as 360x240 or 480x320. Nearly all major online video platforms-even YouTube-now support HD video at a minimum of 720p. Yet that extra resolution also means more bandwidth and computing power on the viewer's end. A professor at a large state university might be able to take advantage of a fast campus network and computer labs. But a high school teacher might be dealing with aging PCs and students who don't have broadband at home.
All that resolution means more bandwidth, both for your servers and for your students. If your overall storage needs are modest then the free version of an online video platform might be adequate. However, it's amazing how quickly the gigabytes add up in HD, so keeping more than a couple of hours available to a school full of students will likely cost you.
Having HD video as a real and practical option is nonetheless a real boon for enhancing education online. Beyond the hype there are good reasons to use HD, and there are still good reasons to choose standard definition. Choose wisely, and you'll get compliments from your students and from your bookkeeper.