Green Screen + EX? at DVinfo.net

Leonard Levy · December 20th, 2007, 02:27 AM

Has anyone tested the EX on green screen footage yet?

Tuomas Sebastien · December 20th, 2007, 05:15 AM

I'd like to know how well EX1's HQ mode with 4:2:0 keys compared to DigiBeta 4:2:2. Will the resolution advantage of EX1 key better or will the reduced color grading (or what the hell these where called again) cause unwanted leaks that resolution can't compensate.

Thomas Smet · December 20th, 2007, 10:00 AM

well now that all depends. How can you compare SD to HD? If you plan to down convert the EX1 footage to SD in your timeline to match digibeta then it could end up looking better. Sure 1920x1080 only has 960x540 chroma pixels but that is still more then 720x480's 360x480. Yes ratio is important but again we are talking HD here and not SD. If you wanted to compare SD 4:2:0 to SD 4:2:2 well then of course the 4:2:2 would be better but this isn't the case here.

If you had HD 4:2:2 it would of course be better but it is no where even close to garbage like some people would make you think.

I am a compositor by trade by while I prefer 4:4:4 for my own sick twisted reasons I am fine with 4:2:0 as long as it is dealt with properly.

Keep in mind that progressive 4:2:0 is better then interlaced 4:2:0. If you plan on shooting 720p with the EX1 or shooting 24p,30p or 25p then you will get some darn good results. Turn down the edge enhancement and it will be even better.

Brian Rhodes · December 20th, 2007, 10:40 AM

I shot some footage in the SP mode. I use the V1u as my B roll cam. The footage keyed very well its was shot with dim available light. I try to post some footage today.

Brian Rhodes · December 20th, 2007, 08:42 PM

Quote:

Originally Posted by Brian Rhodes

I shot some footage in the SP mode. I use the V1u as my B roll cam. The footage keyed very well its was shot with dim available light. I try to post some footage today.

Green Screen keyed footage wmv Format
XDCAMEX SP mode 24p V1u B roll

http://www.dvdaction.net/index_010.htm

John Hess · December 23rd, 2007, 02:42 PM

I shot some Chromakey using a fold out greenscreen in my backyard. Used Cineform and Keylight in AfterEffects to pull the key.

http://www.gospeljohn.net/webpages/E...creentest.html

HVX users can say what they want about their 4:2:2 compression... I choose resolution over their 4:2:2 any day.

Leonard Levy · December 23rd, 2007, 02:50 PM

Thanks John, Finally a real test.

Any chance you can put somebody with frizzy hair in front of it. (Or just make yours go wild if you can ). That's the real question.

I had no doubt it would key someone with clean edges well.

By the way I'm as interested in your subjective opinion of the results as i am in looking at footage because I am always looking at compressed footage on the web and don't trust it.

There was alot of ghosting in the hand movement I saw on my computer. Is that web compression or was that really in the picture?
I'm no expert on green screen but it didn't look good to me. here.

Lenny

Steven Thomas · December 23rd, 2007, 03:54 PM

It looked good to me.

Remember it's 24P.
Standing in front of a camera waving your arms is going to show mothion blur, especially at 24P.

Also, the original was 1920x1080. I can only imagine it looked decent.

John Hess · December 24th, 2007, 12:24 AM

Quote:

Originally Posted by Steven Thomas

It looked good to me.

Remember it's 24P.
Standing in front of a camera waving your arms is going to show mothion blur, especially at 24P.

Also, the original was 1920x1080. I can only imagine it looked decent.

Absolutely right.

The frizzy edging on the fast hand movement has more to due with motion blur than compression. Next time I'm pushing the shutter speed to warp 9.

I was actually quite impressed by the quality of the key. The frizzy hair test may have more to do with the chromakey software capability than the 4:2:2 compression...

What I did notice was the nice key that it pulled from the inner rim of my glasses...keep an eye out for it if you watch it again.

Leonard Levy · December 24th, 2007, 01:35 AM

John,

As I mentioned I'm no expert on Green screen and have never pulled a key myself. I've shot a great deal of it though and I try to be extremely careful. Pretty much the only problem that I ever hear complaints about is always frizzy hair.

Incidently, what IRE was your green screen at?

With the HVX200 I had to raise the greens screen level to about 55-60 to get away from the noise. I was used to shooting it about 40.

Thanks again for the test. Do you do a lot of Green screen?

Lenny

John Hess · December 24th, 2007, 01:47 AM

I do very little green screen actually but when I do it, I've never really had too much trouble with it.

I didn't check the IRE on the greenscreen - I just threw out a portable screen on an overcast day and started shooting. From what I can judge, it looks like it's around 40 or 50. Noise is certainly not a problem with this camera.

I'll try some frizzy hair for you if I can get a chance!

Joe Lawry · December 24th, 2007, 04:22 AM

Very nice both Brian and John, the footage looks great from both of you.

Looking forward to seeing someone with some messy hair next, female shoulder length is usually the one to give me trouble with 4:2:0.. although last time i did that it was interlaced. Eww.

Andrew Wilson · December 24th, 2007, 10:14 AM

John,

Thanks for doing that test. When you say "Imported using Cineform Prospect and transcoded using "FilmScan" setting" how is that different from bringing the footage into FCP? It's all really about the same 4:2:0 isn't it? What are you using for post?

Steven Thomas · December 24th, 2007, 11:21 AM

Since he's using Cineform, filmscan is a name for one of their quality settings (second from the best) when converting to the Cineform intermediate.
Cineform will also convert the 4:2:0 GOP to 4:2:2 Intraframe. Of course it will not increase the chroma samples, but this process adds for better grading in post.

IMO, Cineform is one of the best, if not the best intermediate solutions you can buy!

Andrew Wilson · December 24th, 2007, 11:58 AM

What platform is that? Is it similar to converting to ProRes422 in FCP?

Since he shot it outdoors, that pretty much guarantees that the footage was recorded to the SxS card and we not looking at a HD-SDI capture workflow, right?

Do you have a wafian you're not telling us about?

December 20th, 2007, 02:27 AM	#1
Leonard Levy Trustee Join Date: Feb 2006 Location: USA Posts: 1,684	Green Screen + EX? Has anyone tested the EX on green screen footage yet?

December 20th, 2007, 05:15 AM	#2
Tuomas Sebastien Regular Crew Join Date: Nov 2007 Location: Finland Posts: 107	I'd like to know how well EX1's HQ mode with 4:2:0 keys compared to DigiBeta 4:2:2. Will the resolution advantage of EX1 key better or will the reduced color grading (or what the hell these where called again) cause unwanted leaks that resolution can't compensate.

December 20th, 2007, 10:00 AM	#3
Thomas Smet Trustee Join Date: Mar 2004 Location: Milwaukee, WI Posts: 1,719	well now that all depends. How can you compare SD to HD? If you plan to down convert the EX1 footage to SD in your timeline to match digibeta then it could end up looking better. Sure 1920x1080 only has 960x540 chroma pixels but that is still more then 720x480's 360x480. Yes ratio is important but again we are talking HD here and not SD. If you wanted to compare SD 4:2:0 to SD 4:2:2 well then of course the 4:2:2 would be better but this isn't the case here. If you had HD 4:2:2 it would of course be better but it is no where even close to garbage like some people would make you think. I am a compositor by trade by while I prefer 4:4:4 for my own sick twisted reasons I am fine with 4:2:0 as long as it is dealt with properly. Keep in mind that progressive 4:2:0 is better then interlaced 4:2:0. If you plan on shooting 720p with the EX1 or shooting 24p,30p or 25p then you will get some darn good results. Turn down the edge enhancement and it will be even better.

December 20th, 2007, 10:40 AM	#4
Brian Rhodes Major Player Join Date: Nov 2005 Location: Houston, Texas Posts: 753	I shot some footage in the SP mode. I use the V1u as my B roll cam. The footage keyed very well its was shot with dim available light. I try to post some footage today.

December 23rd, 2007, 02:42 PM	#6
John Hess New Boot Join Date: Sep 2007 Location: Temecula, CA Posts: 19	I shot some Chromakey using a fold out greenscreen in my backyard. Used Cineform and Keylight in AfterEffects to pull the key. http://www.gospeljohn.net/webpages/E...creentest.html HVX users can say what they want about their 4:2:2 compression... I choose resolution over their 4:2:2 any day.

December 23rd, 2007, 02:50 PM	#7
Leonard Levy Trustee Join Date: Feb 2006 Location: USA Posts: 1,684	Thanks John, Finally a real test. Any chance you can put somebody with frizzy hair in front of it. (Or just make yours go wild if you can ). That's the real question. I had no doubt it would key someone with clean edges well. By the way I'm as interested in your subjective opinion of the results as i am in looking at footage because I am always looking at compressed footage on the web and don't trust it. There was alot of ghosting in the hand movement I saw on my computer. Is that web compression or was that really in the picture? I'm no expert on green screen but it didn't look good to me. here. Lenny

December 23rd, 2007, 03:54 PM	#8
Steven Thomas Trustee Join Date: Sep 2005 Location: Gilbert, AZ Posts: 1,896	It looked good to me. Remember it's 24P. Standing in front of a camera waving your arms is going to show mothion blur, especially at 24P. Also, the original was 1920x1080. I can only imagine it looked decent.

December 24th, 2007, 01:35 AM	#10
Leonard Levy Trustee Join Date: Feb 2006 Location: USA Posts: 1,684	John, As I mentioned I'm no expert on Green screen and have never pulled a key myself. I've shot a great deal of it though and I try to be extremely careful. Pretty much the only problem that I ever hear complaints about is always frizzy hair. Incidently, what IRE was your green screen at? With the HVX200 I had to raise the greens screen level to about 55-60 to get away from the noise. I was used to shooting it about 40. Thanks again for the test. Do you do a lot of Green screen? Lenny

December 24th, 2007, 01:47 AM	#11
John Hess New Boot Join Date: Sep 2007 Location: Temecula, CA Posts: 19	I do very little green screen actually but when I do it, I've never really had too much trouble with it. I didn't check the IRE on the greenscreen - I just threw out a portable screen on an overcast day and started shooting. From what I can judge, it looks like it's around 40 or 50. Noise is certainly not a problem with this camera. I'll try some frizzy hair for you if I can get a chance!

December 24th, 2007, 04:22 AM	#12
Joe Lawry Major Player Join Date: Jul 2004 Location: Auckland, New Zealand Posts: 418	Very nice both Brian and John, the footage looks great from both of you. Looking forward to seeing someone with some messy hair next, female shoulder length is usually the one to give me trouble with 4:2:0.. although last time i did that it was interlaced. Eww.

December 24th, 2007, 10:14 AM	#13
Andrew Wilson Tourist Join Date: Nov 2007 Location: Vermont, USA Posts: 123	John, Thanks for doing that test. When you say "Imported using Cineform Prospect and transcoded using "FilmScan" setting" how is that different from bringing the footage into FCP? It's all really about the same 4:2:0 isn't it? What are you using for post?

December 24th, 2007, 11:21 AM	#14
Steven Thomas Trustee Join Date: Sep 2005 Location: Gilbert, AZ Posts: 1,896	Since he's using Cineform, filmscan is a name for one of their quality settings (second from the best) when converting to the Cineform intermediate. Cineform will also convert the 4:2:0 GOP to 4:2:2 Intraframe. Of course it will not increase the chroma samples, but this process adds for better grading in post. IMO, Cineform is one of the best, if not the best intermediate solutions you can buy!

December 24th, 2007, 11:58 AM	#15
Andrew Wilson Tourist Join Date: Nov 2007 Location: Vermont, USA Posts: 123	What platform is that? Is it similar to converting to ProRes422 in FCP? Since he shot it outdoors, that pretty much guarantees that the footage was recorded to the SxS card and we not looking at a HD-SDI capture workflow, right? Do you have a wafian you're not telling us about?