Chroma Keying at DVinfo.net

Bev Standish · February 6th, 2005, 10:46 PM

Has anyone done any chroma key work with these cameras? If so how hard was it? I have heard that pulling a key is more difficult with HD than SD. Is that so?

Thanks very much for any thoughts or experience with this.

Bev

Mike Tiffee · February 7th, 2005, 11:00 AM

I've done it via after effects.. the key looks pretty good... on a still you can see blocky artifacts, but when moving, the key is very crisp, doesn't dance around, looks awesome, especially if you're going to downconvert to SD.

here's a framegrab:

http://www.miketiffee.com/hdv/chromakeytest.jpg

Bev Standish · February 7th, 2005, 02:44 PM

Thank you so much for your help Mike! Which camera did you use? Was it the FX1 or the Z1? If it's not too much trouble, what kind of lights?

Thanks again!

Bev

Douglas Spotted Eagle · February 7th, 2005, 03:32 PM

I've also done quite a bit, and will post some of it later in the week for you to play with. Using the 4:2:2 DI, it keys rather nicely, but the transport stream doesn't.
I'm shooting a Z1, using Photoflex softboxes against a Photoflex Flexdrop.

Bev Standish · February 7th, 2005, 04:49 PM

Thank you Douglas for your reply! what exactly do you mean by transport stream? I can't tell whether this is good news about chroma key or not.

Thank you very much for taking the time to post!

Bev

Douglas Spotted Eagle · February 7th, 2005, 04:52 PM

HDV cameras output what's called an M2T file, or a transport stream file. It needs to be decoded. Some people edit transport streams directly, which is foolish, and others use what's called a DI, or digital intermediary. that's the better way to go.

Bev Standish · February 7th, 2005, 05:52 PM

So what is your capture to edit process?

Thank you for your time!

Bev

Douglas Spotted Eagle · February 7th, 2005, 07:07 PM

Bev, I capture using the HDLink software from Cineform. It's PC only, so if you're in the Apple world, it's a little different.
In this capture, the m2t stream is converted to an avi stream. It creates a stream that's much easier for an NLE to work with, correct, and key with.

Joel Corral · February 8th, 2005, 01:06 PM

<<<-- Originally posted by Douglas Spotted Eagle : HDV cameras output what's called an M2T file, or a transport stream file. It needs to be decoded. Some people edit transport streams directly, which is foolish, and others use what's called a DI, or digital intermediary. that's the better way to go. -->>>

Douglas,

why is editing from the transport stream file foolish? is that native editing? pinnacle and canopus have embraced native editing. can you explain your view.

thanks,

joel

Laurence Maher · February 11th, 2005, 03:59 AM

Hey Douglas Spotted Eagle,

You mentioned 4:2:2 via DI. Are you saying you get 4:2:2 out of the Z1 via some method such as the component outs?

Thanks.

Douglas Spotted Eagle · February 11th, 2005, 08:10 AM

No. When you use the Cineform DI, the 4:2:0 long GOP is converted to a 4:2:2/2 GOP.

Filip Kovcin · February 11th, 2005, 08:15 AM

<<<-- Originally posted by Bev Standish : Has anyone done any chroma key work with these cameras? If so how hard was it? I have heard that pulling a key is more difficult with HD than SD. Is that so? -->>>

just a suggestion,

i do not know if this is mentioned somewhere earlier - but try to experiment with polarising filter whent shooting in front of blue/green screen.

filip

February 6th, 2005, 10:46 PM	#1
Bev Standish New Boot Join Date: Feb 2005 Location: Tigard, Oregon Posts: 6	Chroma Keying Has anyone done any chroma key work with these cameras? If so how hard was it? I have heard that pulling a key is more difficult with HD than SD. Is that so? Thanks very much for any thoughts or experience with this. Bev __________________ Bev Standish Wolfsong Studios

February 7th, 2005, 02:44 PM	#3
Bev Standish New Boot Join Date: Feb 2005 Location: Tigard, Oregon Posts: 6	Thank You! Thank you so much for your help Mike! Which camera did you use? Was it the FX1 or the Z1? If it's not too much trouble, what kind of lights? Thanks again! Bev __________________ Bev Standish Wolfsong Studios

February 7th, 2005, 03:32 PM	#4
Douglas Spotted Eagle VASST Join Date: Jan 2004 Location: Stockton, UT Posts: 5,648	I've also done quite a bit, and will post some of it later in the week for you to play with. Using the 4:2:2 DI, it keys rather nicely, but the transport stream doesn't. I'm shooting a Z1, using Photoflex softboxes against a Photoflex Flexdrop. __________________ Douglas Spotted Eagle/Spot Author, producer, composer Certified Sony Vegas Trainer http://www.vasst.com

February 7th, 2005, 04:49 PM	#5
Bev Standish New Boot Join Date: Feb 2005 Location: Tigard, Oregon Posts: 6	Transport Stream Thank you Douglas for your reply! what exactly do you mean by transport stream? I can't tell whether this is good news about chroma key or not. Thank you very much for taking the time to post! Bev __________________ Bev Standish Wolfsong Studios

February 7th, 2005, 04:52 PM	#6
Douglas Spotted Eagle VASST Join Date: Jan 2004 Location: Stockton, UT Posts: 5,648	HDV cameras output what's called an M2T file, or a transport stream file. It needs to be decoded. Some people edit transport streams directly, which is foolish, and others use what's called a DI, or digital intermediary. that's the better way to go. __________________ Douglas Spotted Eagle/Spot Author, producer, composer Certified Sony Vegas Trainer http://www.vasst.com

February 7th, 2005, 11:00 AM	#2
Mike Tiffee Regular Crew Join Date: Oct 2004 Posts: 150	I've done it via after effects.. the key looks pretty good... on a still you can see blocky artifacts, but when moving, the key is very crisp, doesn't dance around, looks awesome, especially if you're going to downconvert to SD. here's a framegrab: http://www.miketiffee.com/hdv/chromakeytest.jpg

February 7th, 2005, 05:52 PM	#7
Bev Standish New Boot Join Date: Feb 2005 Location: Tigard, Oregon Posts: 6	Thanks again! So what is your capture to edit process? Thank you for your time! Bev __________________ Bev Standish Wolfsong Studios

February 7th, 2005, 07:07 PM	#8
Douglas Spotted Eagle VASST Join Date: Jan 2004 Location: Stockton, UT Posts: 5,648	Bev, I capture using the HDLink software from Cineform. It's PC only, so if you're in the Apple world, it's a little different. In this capture, the m2t stream is converted to an avi stream. It creates a stream that's much easier for an NLE to work with, correct, and key with. __________________ Douglas Spotted Eagle/Spot Author, producer, composer Certified Sony Vegas Trainer http://www.vasst.com

February 8th, 2005, 01:06 PM	#9
Joel Corral Major Player Join Date: Nov 2003 Location: Brea, CA Posts: 356	<<<-- Originally posted by Douglas Spotted Eagle : HDV cameras output what's called an M2T file, or a transport stream file. It needs to be decoded. Some people edit transport streams directly, which is foolish, and others use what's called a DI, or digital intermediary. that's the better way to go. -->>> Douglas, why is editing from the transport stream file foolish? is that native editing? pinnacle and canopus have embraced native editing. can you explain your view. thanks, joel

February 11th, 2005, 03:59 AM	#10
Laurence Maher Join Date: May 2004 Location: denton, texas, usa Posts: 416	Hey Douglas Spotted Eagle, You mentioned 4:2:2 via DI. Are you saying you get 4:2:2 out of the Z1 via some method such as the component outs? Thanks.

February 11th, 2005, 08:10 AM	#11
Douglas Spotted Eagle VASST Join Date: Jan 2004 Location: Stockton, UT Posts: 5,648	No. When you use the Cineform DI, the 4:2:0 long GOP is converted to a 4:2:2/2 GOP. __________________ Douglas Spotted Eagle/Spot Author, producer, composer Certified Sony Vegas Trainer http://www.vasst.com

February 11th, 2005, 08:15 AM	#12
Filip Kovcin Major Player Join Date: Dec 2003 Location: warsaw, poland Posts: 440	Re: Chroma Keying <<<-- Originally posted by Bev Standish : Has anyone done any chroma key work with these cameras? If so how hard was it? I have heard that pulling a key is more difficult with HD than SD. Is that so? -->>> just a suggestion, i do not know if this is mentioned somewhere earlier - but try to experiment with polarising filter whent shooting in front of blue/green screen. filip __________________ in kino (sic!) veritas