16bit?

[JitCam]

hey all,

when using 720p hvx footage in after effects, should i be using 16bit color depth plugins? or just standard plugins ... also does afterefx need to be set up in any particular way for a higher color depth when using HD footage?


cheerios!

:beer: rogar-Smoke(DBG):

 

[Matt Grunau]

It is my understanding that an HVX's color sampling rate is 4.2.2. The DVX100 series is 4.1.1, so one could say they HVX for all practical purposes has double the amount of colors it records.

A very helpful read is Barry Green's article on Color Sampling, located here:

http://www.dvxuser.com/articles/colorspace/


However, that 4.2.2 is still 8 bit color. The only time you would run into 4.4.4 color sampling would be if you created a document in Photoshop and saved it as a 24 bit .tga file (the 24 meaning 8 bits for all three color channels).

Setting AE to be 16 bit color is easy, just go to File>Project settings, and change your color depth to 16.

In most cases, 16 bit color wont help you as far as image quality, but what it can do is give you more latitude with issues like banding in gradients, as well as the Levels tool, and other tools that affect your footage similarly, where you wish to have those extra shades to avoid artifacts. However, when you save your footage, unless you save it in a 16 bit format, you will lose the 16 bit workspace. That's ok though, since the help 16 bit offered putting the project together will still be there, just reduced to 8 bit, and still managing to avoid some of 8 bit's (occasional) nasty artifacts.


In 8 bit color, there are 8 "slots" in which to hold a binary value of either 1 or 0, essentially resulting in a number that it 2 to the power of 8 (256) which is why in Photoshop we have 256 shades of each color channel to mix and create different hues and saturation. Take those 256 shades per channel and multiply all three channels and you get the number we are familiar with: 16.7 million. That's the amount of colors your computer monitor displays when in 24 bit or "true" color mode.

16 bit on the other hand has 16 slots in which to hold a binary value, giving us 2 to the power of 16 colors. That means 65,536 shades of color per channel. Take those channels and multiply them by the shades per channel and you get a staggering 281,474,976,710,656 colors. That's 281 Trillion colors.

That's one of the reasons computer monitors can't display 16 bit per channel color . . . yet. But with all those extra colors, working in 16 bit mode gives you a hell of a lot of room to play. And you will notice if you are working in 16 bit and you go to render say a Quicktime, you will see as an option Trillions of colors. That's why.

Hope that helps. Excuse me now as my brain is melting.

 

[JitCam]

Matt,

great post! u answered my question completely, thanx!! I don't know why i had the impression that 4.2.2 was 16 bit color! anywayz, thanx again