I work in the promotions dept at a news shop that is currently still SD-only. Our Macs have AJA Kona cards, so they are HD-capable, but so far we have only used them for SD editing.
We are doing a try-out of a JVC-250 camera next month. I was looking online at some of the specs, and best I could tell it recorded only to HDV codec for HD and DV codec for SD.
Most of my knowledge on HD so far has been from what I've read. My understanding is the idea of HDV is that it squeezes HD resolution into the same datarate as DV/SD by using MPEG-2 instead of the DV codec. Is this correct?
If that's the case, I could see how they could sell consumer and prosumer cameras that only record HD to this codec, but how are they getting away selling pro cameras like the JVC-250 when it only records in MPEG-2?
Am I wrong in thinking that despite a great lens and 3 CCD's, the color resolution will be crap because the codec is recording to 4:2:0 color-space? And that this camera would be useless for any green-screen keying because of artifacting? And I would imagine our AJA Kona cards are kind of a waste in their ability to pipe 10-bit uncompressed in and out when the source would be highly compressed 8-bit video anyway?
When they go to invest in an HD camera for our dept, should I insist on some other format such as XDCAM or P2 or DVCPRO-HD?
Re: JVC-250 and HDV codec by Michael Palmer on Jul 15, 2008 at 5:17:49 am
Wow where to begin, HDV MPEG-2 can deliver unbelievable HD video for news purposes. Every camera has limits that reflect in the overall quality of the image. What makes better quality has been a marketing gimmick of the manufactures, deciding what is an acceptable quality level is up to you. Compressed HD formats will forever have codec debates. My HDV opinion are based on learning what I could do with HDV video in comparison to other compressed HD formats like XD Cam, HD Cam and DVC Pro HD formats. HDV IMO is what you make of it, how you use the camera and how you decide to use it in post. AVCHD or the new AVC-1 from Panasonic is said to have better low bite rate compression quality that would be great for news purposes, but it isn't a main stream workflow right now and time will tell if it will ever get there. MPEG-2 is an extremely powerful compression codec and can offer the end user with the quality they desire with 4:2:2 color space and both inter-frame and intra-frame recording. The only limit right now is what the camera manufactures offer and with HDV it is never going to be more than 25 Mbps Long GOP. However some HDV cameras have digital connection that could allow uncompressed HD signals to be recorded. Convergent Design has new Compact Flash HD-SDI recorders coming out that will unleash the limits of the camera manufactures recording compression levels that now allows you to choose the compression level right for your project, recording to affordable compact flash media with files written to QuickTime .mov files ready for edit directly from the card. If you are in the news world I would look into the Flash XDR from Convergent Design as it will also allow you to live feed converting to ASI.
Re: JVC-250 and HDV codec by Jonathan Capra on Jul 15, 2008 at 6:08:49 am
I feel like our department kinda reaches beyond the requirements of 'news' in that... A) we wouldn't be shooting any news ourselves with this camera... B) we tend to do some promos that are higher field production - some with a lot of green screen/virtual set stuff... and C) we do a couple of half-hour specials a year that are closer to HGTV or Travel Channel in terms of content and visuals... D) we are an arm of a cable company and recently have been getting farmed out do do non-news commercial spots with fairly high-end field production. Wondering if these needs take us beyond HDV.
Notice that there is no full resolution format, even when you have 4:2:2...if you're recording a sub-resolution picture, 4:2:2 isn't applicable after the picture is expanded to full res...
HiDef camcorders under 15,000.00 USD aren't keeping any amazing secrets...the low cost of entry is achieved through compromise.
There was a feature nominated for an Academy Award this year that was shot with Sony HDV cameras wasn't there? Something about dancing?
...also, I've greenscreen keyed HDV and it isn't significantly better/worse than DVC ProHD...if it's shot competently.
Re: JVC-250 and HDV codec by Michael Palmer on Jul 16, 2008 at 3:30:25 am
Tim,
I believe the pixel shifting terminology from Panasonic is something like....
"a 620,000 pixel progressive imager, applies a spatial offset giving it an effective 1.1 million pixel image performance.
Read it for yourself
http://forums.creativecow.net/readpost/142/859190
What????? This is just words to pacify the end users until they reward us with a low cost full raster HD CCD for under 10K US?
And I don't know what P2 DVC Pro HD records 1440x1080, I believe you may be referring to the
AVC-I codec at the lower level. However the ACV-I spec reads 1920x1080 so the spatial processing is at work again. The HPX-2000 is not full raster, only the HPX-3000 and now we are talking 40K US or more.
Here is one addition to your EX Cam line, the Sony EX1/3 HQ 108024p, 30p or 60i record mode= 35Mbps, 4:2:0 1920x1080. Way under 10K US....
Re: JVC-250 and HDV codec by Tim Kolb on Jul 16, 2008 at 4:41:36 am
[Michael Palmer]"And I don't know what P2 DVC Pro HD records 1440x1080, I believe you may be referring to the
AVC-I codec at the lower level. "
DVC ProHD (P2 and tape)-30fps actual raster size stored is 960x720 (1280x720 interpolated decode) and 1280x1080 (1920x1080 interpolated decode)...25fps 1080 actual raster is 1440x1080 (1920x1080 interpolated decode)
Re: JVC-250 and HDV codec by Jonathan Capra on Aug 16, 2008 at 3:53:40 am
Now that I've actually gotten some experience with our first bit of footage shot on the JVC-250, I can confirm my issues with MPEG-2 as an acquisition. My mind had a hard time wrapping my mind around using any interframe codec during acquisition. And what it comes down to is, in my years of shooting/editing DVCAM I never came across a single frame that looked like this:
And I don't really want to hear about how you just have to know how to light it right or pan correctly. The fact of the matter is that if I was recording that same moment with the same conditions and camerawork with our Sony DSR-720, it would have only 525 lines, yes, but it would not look like Q-bert took a crap on it. I am reverting to my original stance as HDV being a stopgap.
