DO THE MATH
What do you do with your desktop during the average day? Check email, surf the web, write reports and real work, post to your blog?
Yeah, me too. Trying to get away from that last thing...
But for the next couple of months, I'll also be working on the opening sequence for an IMAX film.
You've probably seen an IMAX film at your local science center or, increasingly these days, at your local mall. The screens for these things are huge, usually around 5 stories tall. Each frame of an IMAX film is several thousand pixels across, by several thousand pixels down (TV is 720 pixels across by 540 pixels down, maximum--by the time you get the broadcast signal at home it's down to around 400 lines or less for standard NTSC).
As you might imagine, to make a single frame of IMAX is several orders of magnitude more of a digit-crunch than making a single frame of standard TV. Standard TV frames, uncompressed, are around 1 meg apiece, so each second is 30 megs (1 meg x 30 frames per second), and an uncompressed minute is roughly 1.8 gigs. Most systems don't use uncompressed video, though, and today's DV camcorders don't even shoot uncompressed video. Digital video, the kind that can skip across a FireWire cable from your camcorder to your hard drive for editing, playback, whatever, is compressed 5:1. Good compression is your friend.
Well, I did a test render today. Each IMAX frame is 25 megs, compressed (67 megs uncompressed). Twenty-four of them play each second.
My sequence is currently 25 seconds long. Hmm....25 megs per frame x 24 frames per second x 25 seconds equals about 15 gigs.
Pardon my French, but @%$!
I mean, @%$ @%$! 15 gigs for 25 seconds of film! And in all likelihood, the sequence will get longer.
Thank God for FireWire hard drives.











