DVCProHD Chroma Key? at DVinfo.net

Rachael Hastings · August 28th, 2005, 03:37 PM

Hello,

Has anyone been able to get a successful chroma key shooting DVCProHD? And if so, how did you do it and is there any way to see it?

Someone I know did a test on a Nitris and it didn't chroma key well at all. I don't know what was done, but that doesn't make sense to me. Is there any reason anyone knows of why you'd be able to chroma key well with old Betacam but not with DVCProHD?

I'm thinking maybe they went in with firewire and it doesn't work unless you go in HDSDI. But I haven't been able to find anyone who has done this with this format, or HDV that I can see, so I'm trying to find out if this is possible and what the problems truly are (or aren't).

Info appreciated!

Thanks,

Rachael

Nick Jushchyshyn · August 29th, 2005, 01:06 PM

Capture method and format will have a lot to do with this.
As well, of course, as the setup on set. (screen & foreground lighting, etc.)

I haven't keyed DVCPro HD, but have done lots of 4:2:2 HD from CineAlta cameras. The resolution of the CineAlta is larger, but, when captured at 10bit 4:2:2, the image quality and key-ability should be about the same from a data-spec standpoint.

It should key quite well if the shot was setup properly in the first place.

Which camera was used?
How was the data captured?

Glenn Chan · August 29th, 2005, 01:34 PM

If you capture via SDI, it may have a slight advantage in that the deck applies chroma smoothing when you capture via SDI (but not firewire). This is the case with standard definition formats, I don't know what happens with HD.

If you capture firewire, your system may have a chroma smoothing/interpolation filter available to get a cleaner key.

2- Some keying software is better than others.

3- With some chroma keyers, it is better to light the screen dark so you have less spill on the subject. Other chroma keyers with spill suppression options work better with a brightly lit screen (the documentation should say if this is the case).

August 28th, 2005, 03:37 PM	#1
Rachael Hastings Tourist Join Date: Aug 2005 Posts: 1	DVCProHD Chroma Key? Hello, Has anyone been able to get a successful chroma key shooting DVCProHD? And if so, how did you do it and is there any way to see it? Someone I know did a test on a Nitris and it didn't chroma key well at all. I don't know what was done, but that doesn't make sense to me. Is there any reason anyone knows of why you'd be able to chroma key well with old Betacam but not with DVCProHD? I'm thinking maybe they went in with firewire and it doesn't work unless you go in HDSDI. But I haven't been able to find anyone who has done this with this format, or HDV that I can see, so I'm trying to find out if this is possible and what the problems truly are (or aren't). Info appreciated! Thanks, Rachael

August 29th, 2005, 01:06 PM	#2
Nick Jushchyshyn Major Player Join Date: Feb 2004 Location: Philadelphia, PA, USA Posts: 548	Capture method and format will have a lot to do with this. As well, of course, as the setup on set. (screen & foreground lighting, etc.) I haven't keyed DVCPro HD, but have done lots of 4:2:2 HD from CineAlta cameras. The resolution of the CineAlta is larger, but, when captured at 10bit 4:2:2, the image quality and key-ability should be about the same from a data-spec standpoint. It should key quite well if the shot was setup properly in the first place. Which camera was used? How was the data captured?

August 29th, 2005, 01:34 PM	#3
Glenn Chan Inner Circle Join Date: Jun 2003 Location: Toronto, Canada Posts: 4,750	If you capture via SDI, it may have a slight advantage in that the deck applies chroma smoothing when you capture via SDI (but not firewire). This is the case with standard definition formats, I don't know what happens with HD. If you capture firewire, your system may have a chroma smoothing/interpolation filter available to get a cleaner key. 2- Some keying software is better than others. 3- With some chroma keyers, it is better to light the screen dark so you have less spill on the subject. Other chroma keyers with spill suppression options work better with a brightly lit screen (the documentation should say if this is the case).