Most digital still cameras use relatively inefficient Motion JPEG to squeeze video into manageable file sizes. Motion JPEG is capable of compression in the range of 20:1, a far cry from the more sophisticated MPEG-4/H.264 standard which can compress on the order of 50:1. In this sense the word “format” is not to be confused with “file format.” Most video clips are saved as Apple QuickTime (.MOV) or Audio Video Interleave (.AVI) files. MPEG-4 produces smaller files, a significant benefit.
Prepare for the worst. HD video files can fill up a memory card faster than you can say “Who’s going to edit this?” A Pentax K-x, for example, shooting at 720p, can fit barely three minutes of HD video into 1GB of memory card space. If you shoot 1080p with a Canon EOS 5D Mark II you can expect about the same: Canon claims that 12 minutes of full HD will fit on a 4GB card. In any case, expect HD video shooting times to be short and files to be large.
The first is your video-enabled cellular telephone. The second is a DSLR or point-and-shoot digital camera. The third is the dedicated camcorder. Each category is further segmented, of course, as is the wont of the camera industry, and you can bet your house that further segmentation will occur as fast as markets begin to develop.
Canon EOS-1D Mark IV
At first blush, a cell phone may seem like the worst choice for any serious video work. Think again. The current Apple iPhone, for example, can capture movies at VGA (640x480) resolution and at 30 frames per second. We’ll concede that this barely reaches the threshold of acceptable quality. Nonetheless, the omnipresent iPhone has a noteworthy advantage: It’s significantly more likely to be overlooked by security when you go to a rock concert, whereas your three-chip camcorder
won’t make it beyond coat check. And since video sharing websites (like YouTube) are the final destination for many spontaneous videos, VGA resolution is adequate.
Of equal importance, the cell phone market is huge. Enhanced video performance motivates buyers to upgrade. Put two and two together and you have a strong incentive for phone manufacturers to continue to improve video capture capability along the same lines that it has matured in digital still cameras. In fact, much of the heaviest lifting has already been done.