If you’re new to all the media editing stuff and have recently started playing around with high quality photography, movie editing or digital music, you’re bound to come across a certain dilema.

So, why are RAW image files 48 bit when our computer screens can’t even display more than 24 bit, why is audio mastered in 24 bit and crazy sample rates when the final format is a 16 bit CD?

The very simple reason, editability. Take a RAW image file for example. It boast 48 bit color. A regular computer screen, provided you have a display capable of displaying real colors (TN LCD displays can’t for example, while IPS LCDs can), has 24 bit color, or, 8 bit per channel (Red, Green, Blue). Color depth is exponential, meaning 24 bit has 16.8 million colors while 48 bit has 281.5 trillion, about 16.7 million times the amount of color. Well, applying effects on those colors is years ahead of 24 bit color in terms of precision. Even though the eye can’t see it, the photo mastering software’s algorithm sure can.

The same applies to sound. Sound is mastered in higher formats to allow more modifications and corrections without altering the clearness of the sound when downconverted to its published medium.

But not all industries have the luck of dealing with small size technolgies. Video (without audio) is multiple images and it would take too much space to store video in 48 bit. The video realm is much more about how much you can keep of the original source intact while editing it with the most efficient yet fast to decode codec (making the codec less efficient since it’s fast) than about mastering it with the highest quality possible.

Mastering HD video in an uncompressed format would be killer. HD-SDI runs at ~ 1.5 gbps (or 1500 mbps) while the highest possible audio recording format available today (DXD, Digital eXtreme Definition) runs at ~ 8.5 mbps per channel. In 8 discrete channel surround sound, ~ 67.6 mbps, a bit-rate that already rivals some of the bitrate used for the highest quality 1080p mastering solution, and since digital cinema is even higher than that, I wouldn’t want to imagine the quantity of hard-drive space required to edit that.