Green Screen and the HVX200 at DVinfo.net

Go Back   DV Info Net > Panasonic P2HD / AVCCAM / AVCHD / DV Camera Systems > Panasonic P2HD / DVCPRO HD Camcorders

Panasonic P2HD / DVCPRO HD Camcorders
All AG-HPX and AJ-PX Series camcorders and P2 / P2HD hardware.


Reply
 
Thread Tools Search this Thread
Old April 15th, 2005, 10:18 AM   #1
Regular Crew
 
Join Date: Oct 2003
Location: San Antonio Texas
Posts: 85
Green Screen and the HVX200

Can anyone explain to me in simple terms what the heck is going on here? Recently I set up a green screen in my room. I painted a piece of smooth plywood with a recommended (green screen color) ....and lit the green screen equally. In other words. An equal amount of light was hitting all parts of the screen. So I got in the front of the green screen and moved around a little, while capturing the footage with my xl-2 ...i used the chroma option in VEGAS ...and it never really looked that great. When I would try to key out the green, you could see where the light was uneven because it would key some parts of the board before it would key other parts.

So then i start looking at behind the scenes footage of Sin City and Matrix, and you see these huge green screen set ups, but there are dark areas all over the place. I mean you can clearly see very dary shaded areas on the green screen. How do they get away with that? Which brings me to the panasonic hvx200. My friend was telling me that it has to do with 4:1:1 ..4:2:2: and all that. Is that true? ....Will the HVX200 be better for green screen vs. the xl2??

thanks ..

j.


PS. if the HVX is better for green screen than the xl-2, anyone wanna buy an xl2? :)
John Wheeler is offline   Reply With Quote
Old April 15th, 2005, 11:54 AM   #2
Major Player
 
Join Date: Jul 2004
Posts: 587
Well for one they are using sweet stuff like Ultimatte which will key just about anything well.

Yes the HVX should be much better for keying. Twice as much color information!
Aaron Shaw is offline   Reply With Quote
Old April 15th, 2005, 12:18 PM   #3
Regular Crew
 
Join Date: Oct 2003
Location: San Antonio Texas
Posts: 85
Wow, Ultimatte? I looked at their website but theres a bunch of stuff. If i was shooting footage of spaceships in front of the green screen, then wanted to throw in a background in post, would i just need the Advantedge software from ultimatte?

thanks

j.
John Wheeler is offline   Reply With Quote
Old April 15th, 2005, 01:10 PM   #4
Regular Crew
 
Join Date: Jan 2003
Location: Alabama
Posts: 165
Ultimatte is good, but Primatte is more user friendly. If you have After Effects, you can also use Keylight, which is excellent.
Daniel Broadway is offline   Reply With Quote
Old April 15th, 2005, 01:59 PM   #5
Major Player
 
Join Date: Nov 2001
Location: Boston, MA
Posts: 280
The fact of the matter is, pulling a matte from a greenscreen or bluescreen setup isn't a simple process, it's still a bit of an artform. There are plenty of good keyers out there like ultimatte, primatte, et al., but they will only take you so far. In other words, they are great at getting you most of the way. But what makes a truly good matte is in the details.

Unless you've got a perfectly shot element already, getting a good matte requires a fair amount of tweaking, and in many cases, requires multiple keyers setup for different parts of the image! (This is especially true when shooting people)

Keying something like DV footage, which has very little color depth, low spatial resolution, and a fair amount of compression artifacts only multiplies your headaches. So, as Aaron mentions, the HVX presumably will be better for keying, assuming you shoot your greenscreen footagre in HD as opposed to SD, but it's still nowhere near "ideal".
__________________
Casey Visco
Glidecam Industries, Inc.

Casey Visco is offline   Reply With Quote
Old April 16th, 2005, 11:40 AM   #6
Major Player
 
Join Date: Dec 2004
Posts: 295
<<<-- Originally posted by Casey Visco : . . . So, as Aaron mentions, the HVX presumably will be better for keying, assuming you shoot your greenscreen footagre in HD as opposed to SD, but it's still nowhere near "ideal". -->>>

Although the extra resolution of HD will help, it is compressed more, too. The HVX will offer DVCPro 50, which also has 4:2:2 color sampling. This should help with keying in SD.
Lawrence Bansbach is offline   Reply With Quote
Old April 17th, 2005, 11:46 AM   #7
Major Player
 
Join Date: Jul 2004
Location: Juneau, Alaska, USA
Posts: 624
Someone correct me if i'm wrong, but..

Concevably, it would work well to shoot HD (on the HVX) and do your keying in HD. Then use that keyed footage in a SD project.

- Mikko.
Mikko Wilson is offline   Reply With Quote
Old April 17th, 2005, 12:25 PM   #8
Major Player
 
Join Date: Dec 2003
Location: Fort Worth, TX
Posts: 414
Here's a question:

Okay, I know as much about how colorspace works as I do brewing beer... no wait, I know how to brew beer... I know as much about how colorspace works as I do about competing in the olympics... so this may be a pretty obvious answer to some...

Anyways, I remember people saying that you could capture the HDV footage at 4:2:0 and downconvert to end up with 4:2:2... Is there any advantage to capture this DVCPRO HD footage at 4:2:2 and downconverting, or does it pretty much stay at 4:2:2?
__________________
Kevin Dooley
Media Director, Pantego Bible Church
Kevin Dooley is offline   Reply With Quote
Old April 18th, 2005, 09:00 AM   #9
Major Player
 
Join Date: Jul 2004
Posts: 587
It would stay at 4:2:2. With HDV to achieve SD 4:2:2 you would have to discard one field which would leave you with interlacing issues I would imagine.
Aaron Shaw is offline   Reply With Quote
Old April 18th, 2005, 09:11 AM   #10
Hawaiian Shirt Mogul
 
Join Date: Nov 2001
Location: northern cailfornia
Posts: 1,261
"I remember people saying that you could capture the HDV footage at 4:2:0 and downconvert to end up with 4:2:2"

if the theolor space to TAPE/computer was 4:2:0 it will NEVER be able to get to 4:2:2 = you can't get what you never had in the 1st place .. you could also downconvert to 4:4:4 but again the material will never be 4:4:4 it will always have the 4:2:0 color space for green screening ...
Don Donatello is offline   Reply With Quote
Old April 18th, 2005, 10:04 AM   #11
Major Player
 
Join Date: Jul 2004
Location: Juneau, Alaska, USA
Posts: 624
Aah.. i wasn't talking about downresssing to improve color space (impossible).

I was talkign abotu dooin ghte best keyign you can in the HD colorspace, then downrezzing to hide any erros. (the same way you can get away with slightly soft focus if you are shooting for the web...)

- Mikko.
Mikko Wilson is offline   Reply With Quote
Old April 19th, 2005, 06:43 AM   #12
RED Code Chef
 
Join Date: Oct 2001
Location: Holland
Posts: 12,514
John: check out these green screening tutorials for Vegas, they explain how
to work with color differences etc., in my opinion Vegas has a pretty decent
keyer actually!

http://www.digitalpostproduction.com...e.jsp?id=31596
http://www.digitalpostproduction.com...e.jsp?id=31478
__________________

Rob Lohman, visuar@iname.com
DV Info Wrangler & RED Code Chef

Join the DV Challenge | Lady X

Search DVinfo.net for quick answers | Buy from the best: DVinfo.net sponsors
Rob Lohman is offline   Reply With Quote
Old May 27th, 2005, 03:28 AM   #13
Major Player
 
Join Date: Nov 2002
Location: Tokyo
Posts: 898
Ultimatte AdvanTage help!!!

I must have missed it but.....does Ultimatte advantage allow preview with a background overlay while shooting? I need an answer ASAP. Got a shoot coming up and I use a Mac. If U.A. doesn't allow preview, I'll have to get a PC and another software which does. That will put a cramp in the budget!
Dean Harrington is offline   Reply With Quote
Old May 27th, 2005, 09:01 AM   #14
Major Player
 
Join Date: May 2003
Location: Phoenix, AZ
Posts: 327
There's a difference between having a preview overlay while shooting and pulling a good quality key. Even the big boys use inferior technology to pull "live" keys. The ultimate setup would be to have an Ultimatte hardware unit on set. The results can look mighty impressive, but it's always best to have the original bluescreen or greenscreen footage, then do a key you can tweak in post, resorting to multiple keys or rotoscoping when you need to.

The point is, a live key is only used to check composition, contrast and color balance. It doesn't matter if the edges of the key are perfect, just good enough to give you an idea of how the final composite will come together.

Maybe a cheap, used switcher with a chromakey function might be a good tool for on-set previews, then use high quality software like AfterEffects or the Primatte plugin for your keying in post. You could even rent a low-cost switcher for the day of the shoot - probably for less than $50.

Last edited by Scott Anderson; May 27th, 2005 at 03:10 PM.
Scott Anderson is offline   Reply With Quote
Old May 27th, 2005, 09:07 AM   #15
Major Player
 
Join Date: Jan 2005
Location: Cardiff, UK
Posts: 221
Definitely worth you checking out ULTRA too, which uses a vector keying system that doesn't require a perfect screen. Its not too expensive, it has a great set of videos you can check out on their site and there's also a trial you can download. Impresses me anyway!

Thanks for the link to the Digital Post Production site, big big fan of Vegas so always glad to find sites that offer information and tutorials with it.
James Connors is offline   Reply
Reply

DV Info Net refers all where-to-buy and where-to-rent questions exclusively to these trusted full line dealers and rental houses...

Professional Video
(800) 833-4801
Portland, OR

B&H Photo Video
(866) 521-7381
New York, NY

Z.G.C.
(973) 335-4460
Mountain Lakes, NJ

Abel Cine Tech
(888) 700-4416
N.Y. NY & L.A. CA

Precision Camera
(800) 677-1023
Austin, TX

DV Info Net also encourages you to support local businesses and buy from an authorized dealer in your neighborhood.
  You are here: DV Info Net > Panasonic P2HD / AVCCAM / AVCHD / DV Camera Systems > Panasonic P2HD / DVCPRO HD Camcorders

Thread Tools Search this Thread
Search this Thread:

Advanced Search

 



Google
 

All times are GMT -6. The time now is 04:35 PM.


DV Info Net -- Real Names, Real People, Real Info!
1998-2017 The Digital Video Information Network