HDCAM and the F900 at DVinfo.net

Alan James · January 19th, 2007, 01:26 AM

I have been reading a bit about the Sony F900 camera and HDCAM format. I want to know if I am correct in thinking that the signal on the HDCAM format is pretty compressed. First I have read on Wikipedia that HDCAM compresses the resolution to 1440X1080 in the luminance channel and 480X1080 in both color channels. It also puts a 3:2 or a 2:3:3:2 (not really sure) pulldown on the tape and records it in 59.94i. Second it compresses the color signal to 4:2:2 so you only sample color every other frame. Last thing is that it only stores an 8bit signal.

If these things are true then it seems like a pretty crappy format to shoot on. Highly compressed from the original signal the camera sends out. Also if the things stated above are correct then the XL2 and DVX100 are basically the little brother of the F900, because they all three basically compress the same way the XL2 and DVX100 just do it at a much lower resolution.

So are all these things true? And if not someone please explain how the Sony F900 stores to whatever tape format it uses.

(The tape I am talking about is the HDCAM not the HDCAM SR. I understand the SR is a lot better.)

Alan James · January 19th, 2007, 01:45 AM

I just realized this thread should probably be moved to the tape section. If an admin could do that for me it would be great.

Alan James · January 21st, 2007, 03:54 AM

I guess it shouldn’t be moved then.

So no one is biting at this thread. I’m just looking for a yes or no on the facts above. It seems to be that HDCAM. Is very much like HDV is HDCAM really that bad or is HDV really good? Of course HDCAM SR isn’t in the comparison. Thanx all.

Brian Drysdale · January 21st, 2007, 07:42 AM

The important difference is how much better HDCAM handles motion, this is a problem for a highly compressed format like HDV.

HDCAM is an older format, so recording the data required for HD was a big problem - it's actually 3:1:1. It's also a more robust format, a development of DigiBeta rather than the much more fragile MiniDV tapes used on HDV.

HDCAM is compressed 6:1 @ 140 Mbps compared to HDV's 22.39:1 @ 25 Mbps.

Basically, you're going to have a lot more artifacts on HDV compared to HDCAM.

Alan James · January 21st, 2007, 06:32 PM

Whats DV25 and HDCAM SR compression ratio?

Scott Webster · January 21st, 2007, 09:23 PM

Quote:

Originally Posted by Alan James

Whats DV25 and HDCAM SR compression ratio?

Alan, you may find this pdf useful:

http://www.creativecow.net/articles/...data-rates.pdf

Brian Drysdale · January 22nd, 2007, 05:02 AM

Quote:

Originally Posted by Scott Webster

Alan, you may find this pdf useful:

http://www.creativecow.net/articles/...data-rates.pdf

I'd be careful about taking some of those figures at face value, because at first glance it would look like DV and HDV have the same compression levels, which they don't.

Doing some more checking, 7:1 is the commonly quoted figure for HDCAM, although seemingly the data rates vary depending on which frame rate/format you're shooting.

Bruno Donnet · January 22nd, 2007, 05:33 AM

Quote:

Originally Posted by Scott Webster

Alan, you may find this pdf useful:

http://www.creativecow.net/articles/...data-rates.pdf

And the second board of this document mentions a wrong sample color ratio of 4:1:1 for HDV, instead of 4:2:0 (as correctly mentioned in the first board).

Chris Hurd · January 22nd, 2007, 08:34 AM

Quote:

Originally Posted by Alan James

I just realized this thread should probably be moved to the tape section.

Moved from General HD / HDV to Sony XDCAM HD CineAlta -- I know the F900 is HDCAM, not XDCAM, but we're putting all the CineAlta topics into this forum. Our tape forum (The Long Black Line) is best suited for lower-end tape formats such as DV, HDV, and legacy analog formats, etc.

January 19th, 2007, 01:26 AM	#1
Alan James Regular Crew Join Date: Jul 2006 Location: Tampa, Florida Posts: 261	HDCAM and the F900 I have been reading a bit about the Sony F900 camera and HDCAM format. I want to know if I am correct in thinking that the signal on the HDCAM format is pretty compressed. First I have read on Wikipedia that HDCAM compresses the resolution to 1440X1080 in the luminance channel and 480X1080 in both color channels. It also puts a 3:2 or a 2:3:3:2 (not really sure) pulldown on the tape and records it in 59.94i. Second it compresses the color signal to 4:2:2 so you only sample color every other frame. Last thing is that it only stores an 8bit signal. If these things are true then it seems like a pretty crappy format to shoot on. Highly compressed from the original signal the camera sends out. Also if the things stated above are correct then the XL2 and DVX100 are basically the little brother of the F900, because they all three basically compress the same way the XL2 and DVX100 just do it at a much lower resolution. So are all these things true? And if not someone please explain how the Sony F900 stores to whatever tape format it uses. (The tape I am talking about is the HDCAM not the HDCAM SR. I understand the SR is a lot better.)

January 21st, 2007, 03:54 AM	#3
Alan James Regular Crew Join Date: Jul 2006 Location: Tampa, Florida Posts: 261	I guess it shouldn’t be moved then. So no one is biting at this thread. I’m just looking for a yes or no on the facts above. It seems to be that HDCAM. Is very much like HDV is HDCAM really that bad or is HDV really good? Of course HDCAM SR isn’t in the comparison. Thanx all. Last edited by Alan James; January 21st, 2007 at 06:39 PM.

January 19th, 2007, 01:45 AM	#2
Alan James Regular Crew Join Date: Jul 2006 Location: Tampa, Florida Posts: 261	I just realized this thread should probably be moved to the tape section. If an admin could do that for me it would be great.

January 21st, 2007, 07:42 AM	#4
Brian Drysdale Inner Circle Join Date: Feb 2006 Location: Belfast, UK Posts: 6,152	The important difference is how much better HDCAM handles motion, this is a problem for a highly compressed format like HDV. HDCAM is an older format, so recording the data required for HD was a big problem - it's actually 3:1:1. It's also a more robust format, a development of DigiBeta rather than the much more fragile MiniDV tapes used on HDV. HDCAM is compressed 6:1 @ 140 Mbps compared to HDV's 22.39:1 @ 25 Mbps. Basically, you're going to have a lot more artifacts on HDV compared to HDCAM.

January 21st, 2007, 06:32 PM	#5
Alan James Regular Crew Join Date: Jul 2006 Location: Tampa, Florida Posts: 261	Whats DV25 and HDCAM SR compression ratio?