Compression Ratios

[Matty2phatty]

Anybody able to explain to me what compression ratios mean? like 4:4:4, or whatever... and anybody know what the compression ratio is on an XL2? and what are consumer HD cameras approximately? and is it much worse than pro HD?

[miker]

I can never quite remember.

http://www.answers.com/4%3A4%3A4

IIRC, on miniDV, PAL is 4:2:0 and NTSC is 4:1:1 ... aparently PAL has the edge from what I've read elsewhere.

[sn-films]

Here's a nice write-up for you...

http://www.adamwilt.com/DV-FAQ-tech.html

Click the "4:2:2, 4:1:1, 4:2:0" link to skip ahead to the part you're interested in.

And here's a nice illustration for those who may be interested...

http://www.adamwilt.com/pix-sampling.html

[sn-films]

Almost forgot... "4:4:4" is a color sampling ratio, not a compression ratio. "4:4:4" is excellent. "4:2:2" is very good. "4:1:1" or "4:2:0" is what most of us work with.

An XL2 shoots DV, so you're still looking at 4:1:1 (NTSC) or 4:2:0 (PAL) color sampling.

Regarding HiDef, keep in mind that not all HiDef content is created equally... the new Sony and JVC HiDef cameras use the HDV (High Definition Video) format. The color sampling on these cameras is still 4:1:1 or 4:2:0.

Panasonic's HiDef camera that will be released in the fall uses their DVCPRO HD format that utilizes the same color sampling ratio as their DVCPRO50 format... 4:2:2. DVCPRO HD is the same format as their infamous VariCam!

I hope this sheds additional light onto your questions.