PDA

View Full Version : camera terminology 4.4.4 - 4.2.2. - etc?


ant-
02-19-2005, 05:33 PM
I hear people talking about captureing footage from cameras, and often hear them mention a string of 3 numbers after. Ie 3.1.1 or 4.4.4

I just never really bothered asking what they stood for, i'm assuming they are a representation of colour values, or dynamic range?

I would go looking round the net for this info but i dont really know where to start looking.

if someone would point me in the right direction so i dont have such a vacant look on my face next time somone talks to me about about cameras, that would be great, thanks!

suntemple
02-19-2005, 08:44 PM
Do A search for image aspect ratio on the net and you will get the definition and info you're looking for.

Actually, here you go (examples of different formats) http://home.comcast.net/~igpl/Aspect.html.

"Image Aspect Ratio"
"Image ratio refers to the relation of the width of the image to the height. While you can change the size of the image, the ratio stays constant."




Example in terms of visual effects- In compositing and matchmoving, many times the artist will need to modify/match the virtual camera settings in their animation/tracker software in order to compensate for differences/discrepancies between the image aspect ratio in which the real camera was capturing and the image aspect ratio the user defines in the animation software being used. The artist would also match for parallex distortion (image disortion as result of the curvature of the lens) but that's a slightly different matter.
Now you can yack with your friends about image aspect ratios...sort of.:)

curious_69_george
02-19-2005, 08:48 PM
The three numbers are referencing the luminance sampling and the colour sampling.

For every 4 samples of luminance there is 2 samples of red and 2 samples of blue

http://www.studio1productions.com/Articles/411samp.htm

4:4:4 is uncompressed, 4:4:4:4 is uncompressed with an alpha.

suntemple
02-19-2005, 10:25 PM
Wow! I was way off on a different tangent. Thanks for the info.

Cheers.

ant-
02-21-2005, 09:21 AM
thats what I was after, thankyou.

CGTalk Moderation
02-21-2006, 10:00 AM
This thread has been automatically closed as it remained inactive for 12 months. If you wish to continue the discussion, please create a new thread in the appropriate forum.