EX1 & Green Screen

Dave Morrison · February 28th, 2009, 03:00 PM

Quote:

Originally Posted by Dean Sensui

Yep, life can be tough... :-)

It beats canning pineapples.

So THAT'S what it means to be "on the dole"? ;)

Dean Sensui · February 28th, 2009, 03:27 PM

double post

Dean Sensui · February 28th, 2009, 03:28 PM

Quote:

Originally Posted by Dave Morrison

So THAT'S what it means to be "on the dole"? ;)

No, that's what it means to get "canned". . . :-)

It was that summer job as a teenager, operating a palletizer in 90-degree steam heat for 8 hours a day, is what drove me and my friends to get college degrees.

Dave Morrison · February 28th, 2009, 04:01 PM

Touche, Dean!! ;)

I was watching a program this morning on the Discovery Channel about canned foods and never realized that there were few people other than those in Hawaii who even knew what pineapple was until canned foods became available.

Have fun over there. Your state is one place I'd love to see before I shuffle off this mortal coil.
dave

p.s. sorry for the threadc**p folks....back to the show

Rob Collins · February 28th, 2009, 05:29 PM

I've had good results with Keylight within FCP: The Foundry Keylight - PlugInFinder | Toolfarm's Plug-in Finder

Here's a little green screen video I did for my church: http://robcollins.net/gnn

Bob Grant · February 28th, 2009, 06:42 PM

Didn't see this thread before!
I'm trying to shoot an extreme closeup of talent with long hair with them deliberately flicking their hair around to then be keyed. Delivery is 1080p. So far I'm not having a lot of success.
So far things I've done wrong and will correct in my next test:

1) Using a blue instead of green screen.
2) Forgetting to turn detail Off.

I'm finding the single strands of hair are a nightmare to key when they're in motion.
Tools I have are Vegas's basic keyer, Keylight in AE and Ultra. Oddly enough to date Vegas's basic keyer seems to do the best job.
I've also taken on board suggestions to key the hair seperately. This might not be a trivial task as the talent will be moving their head a lot but indeed keyer settings that seem to work OK for the hair do not work well for the rest of the frame and edge correction is impossible on such fine hair but OK on the body of the talent.

Any and all suggestions appreciated, I'm kind of at the point of thinking rear projection would be a better option than keying.

Ben Hogan · March 1st, 2009, 02:42 AM

I've had the same success using the keyer in Vegas over some others. And with Vegas I can edit my video with all the other elements and not export video to be keyed and then importing back in, etc.

I've wondered what some of the tricks are to cut down on motion when keying; meaning when you get motion blur, the key falls apart. I'm trying to learn what can be done to minimize that other than not having the talent move hands too fast, etc. But my client is part Italian from New Jersey, so he talks using his hands a lot. But for things other than talking heads, such as jumping, dancing, etc.

I'm guessing the more expensive your key program the better your results. Obviously Hollywood can accomplish very clean chroma-key but then I'm sure using 4:2:2 and big budgets helps a lot.

Dean Sensui · March 1st, 2009, 03:08 AM

The "key" in keying is the program's ability to distinguish what's green, what's not and what's in-between.

Subtle discrimination and spill control is what makes Primatte so powerful. To eliminate green edges Keylight has to cut away at the foreground element. It works but it's a bit crude. The equivalent of chopping away anything that doesn't look good, even though it might contribute to certain essential foreground elements.

Programs such as Primatte and Ultimatte turn most of those edges into transitions.

So elements such as smoke, fine hair and even translucent veils and plastic can be keyed.

You don't need 4:2:2 to get a good key, although it certainly helps. XDCamEX, with it's 4:2:0 sampling provides very good keying data partly because of the full 1920x1080 raster.

Just to re-iterate: it helps a LOT to get a good shot from the start. Make sure your optics are as clean. Expose the green screen at 50 IRE and white balance based on the light that illuminates your green screen, or at least make sure it's green and not some other blend of colors. For example, it's OK to light your green screen with green lights. Just make sure you're not spilling all over your foreground elements and talent. Turn off your edge sharpening in the camera. Shoot progressive at max resolution of 1080, and not interlaced. Keep your gain at zero.

If you can record the 4:2:2 output of the camera that's even better. If not, the 4:2:0 sampling on the SxS card works well, too.

Michael Cox · March 7th, 2009, 12:54 AM

I am just starting out I have an FX7 that shoots 1080i. I don't think I can do 1080p but I'm not sure. My concern is I keep reading on this thread that you should use p. Any info is appreciated fellas. Thanks...

Dean Sensui · March 7th, 2009, 01:37 AM

For interlaced material, the usual procedure is to de-interlace first. Do the composite. Then re-interlace.

April 11th, 2009, 04:32 AM

Quote:

Originally Posted by Dean Sensui

Mike...

I'm shooting in a studio.

Love that! All the praise you need Dean...and thanks for sharing your knowledge. Thinking a lot about the less conventional approach.

Interesting to hear all the talk of these third party (costly?) plugins. In addition to standard RGB and Chroma keyers Avid ships with Spectramatte which works very well indeed. Cant keep up with all the latest competing software sellers!!!

I shot Bonnie Tyler against blue once. When I went to key it I found it was the exact same blue as her eyes >doh< hours of tracking/masking fun!!! Check your subject and props carefully is my top tip!

BD

Leonard Levy · April 11th, 2009, 01:16 PM

Dean's discovery that he needed to blue up his fill is key (pun intended) to the kind of thinking you need to make it look natural. Match the light, (and the feeling of saturation which will come from how hard the light is) of the original scene as much as possible.

Actually in Dean's shots I would suggest that perhaps a little cool bounce backlight or top light would be even closer to to matching how someone outside is lit because that same sky fill light is also hitting the tops and sides of the subject. Dean's shots look great though so its obviously not always neccessary.

Sometimes the purpose of that that top or back light is to overwhelm reflection of the green screen in the subjects hair or clothes. That can be helped just by putting white or black cards around the green screen just out of shot to minimize the reflection.

I used to always put my blue & green screens down at 40% in the BETA days, but had noise problems when I started using the HVX200. Jim Arthurs from Texas who's done lots of green screen with the EX and other cameras suggested raising it to 60%. I've been wary of 60 but switched to 55% after that. I think he still does his blue screens lower though. Jim was the first guy on these forums to rave about what a good key you could get with the EX-1 despite it being 4:2:0
Lenny Levy

Mitchell Lewis · April 11th, 2009, 01:27 PM

I recently did a chroma key test shoot shooting 1080 30p HQ. When the model was framed down to her waist only, the key looked great. But the client wanted to see the model walking from a distance toward the camera. Because the model was a short distance away, she was about 1/4 the size of the video frame. When I tried to get a good key on her at this distance, the edges didn't look that great (stair-stepped, pixelated). Having your model be as large as possible in the frame really helps you get a good quality key.

Anyone have any experience using the EX1/EX3 chroma key for a "virtual set" where the model is at a greater distance to the camera?

Kenn Christenson · April 11th, 2009, 02:41 PM

If you're getting a full-body shot - try mounting the camera sideways (portrait mode) to get the maximum amount of pixels dedicated to your subject.

Mitchell Lewis · April 11th, 2009, 02:45 PM

Whoa! How do you guys come up with this stuff? I never would have thought of that. Thanks Kenn.

Now I just have to figure out how to mount the camera sideways! :)

February 28th, 2009, 03:27 PM	#32
Dean Sensui Inner Circle Join Date: Oct 2001 Location: Honolulu, HI Posts: 2,054	double post __________________ Dean Sensui Exec Producer, Hawaii Goes Fishing

February 28th, 2009, 04:01 PM	#34
Dave Morrison Major Player Join Date: May 2002 Location: West Central Florida Posts: 762	Touche, Dean!! ;) I was watching a program this morning on the Discovery Channel about canned foods and never realized that there were few people other than those in Hawaii who even knew what pineapple was until canned foods became available. Have fun over there. Your state is one place I'd love to see before I shuffle off this mortal coil. dave p.s. sorry for the threadc**p folks....back to the show __________________ EX1, Nikon D750 http://www.morrisonphotographics.com http://www.heritagefilm.com

March 1st, 2009, 03:08 AM	#38
Dean Sensui Inner Circle Join Date: Oct 2001 Location: Honolulu, HI Posts: 2,054	The "key" in keying is the program's ability to distinguish what's green, what's not and what's in-between. Subtle discrimination and spill control is what makes Primatte so powerful. To eliminate green edges Keylight has to cut away at the foreground element. It works but it's a bit crude. The equivalent of chopping away anything that doesn't look good, even though it might contribute to certain essential foreground elements. Programs such as Primatte and Ultimatte turn most of those edges into transitions. So elements such as smoke, fine hair and even translucent veils and plastic can be keyed. You don't need 4:2:2 to get a good key, although it certainly helps. XDCamEX, with it's 4:2:0 sampling provides very good keying data partly because of the full 1920x1080 raster. Just to re-iterate: it helps a LOT to get a good shot from the start. Make sure your optics are as clean. Expose the green screen at 50 IRE and white balance based on the light that illuminates your green screen, or at least make sure it's green and not some other blend of colors. For example, it's OK to light your green screen with green lights. Just make sure you're not spilling all over your foreground elements and talent. Turn off your edge sharpening in the camera. Shoot progressive at max resolution of 1080, and not interlaced. Keep your gain at zero. If you can record the 4:2:2 output of the camera that's even better. If not, the 4:2:0 sampling on the SxS card works well, too. __________________ Dean Sensui Exec Producer, Hawaii Goes Fishing

March 7th, 2009, 12:54 AM	#39
Michael Cox Regular Crew Join Date: Jan 2009 Location: Phoenix AZ Posts: 31	Sorry for the dumb ? I am just starting out I have an FX7 that shoots 1080i. I don't think I can do 1080p but I'm not sure. My concern is I keep reading on this thread that you should use p. Any info is appreciated fellas. Thanks...

March 7th, 2009, 01:37 AM	#40
Dean Sensui Inner Circle Join Date: Oct 2001 Location: Honolulu, HI Posts: 2,054	For interlaced material, the usual procedure is to de-interlace first. Do the composite. Then re-interlace. __________________ Dean Sensui Exec Producer, Hawaii Goes Fishing

February 28th, 2009, 05:29 PM	#35
Rob Collins Major Player Join Date: Jul 2007 Location: Richmond, VA Posts: 229	I've had good results with Keylight within FCP: The Foundry Keylight - PlugInFinder \| Toolfarm's Plug-in Finder Here's a little green screen video I did for my church: http://robcollins.net/gnn

February 28th, 2009, 06:42 PM	#36
Bob Grant Trustee Join Date: Nov 2005 Location: Sydney Australia Posts: 1,570	Didn't see this thread before! I'm trying to shoot an extreme closeup of talent with long hair with them deliberately flicking their hair around to then be keyed. Delivery is 1080p. So far I'm not having a lot of success. So far things I've done wrong and will correct in my next test: 1) Using a blue instead of green screen. 2) Forgetting to turn detail Off. I'm finding the single strands of hair are a nightmare to key when they're in motion. Tools I have are Vegas's basic keyer, Keylight in AE and Ultra. Oddly enough to date Vegas's basic keyer seems to do the best job. I've also taken on board suggestions to key the hair seperately. This might not be a trivial task as the talent will be moving their head a lot but indeed keyer settings that seem to work OK for the hair do not work well for the rest of the frame and edge correction is impossible on such fine hair but OK on the body of the talent. Any and all suggestions appreciated, I'm kind of at the point of thinking rear projection would be a better option than keying.

March 1st, 2009, 02:42 AM	#37
Ben Hogan Regular Crew Join Date: Feb 2008 Location: Grapevine Texas Posts: 27	I've had the same success using the keyer in Vegas over some others. And with Vegas I can edit my video with all the other elements and not export video to be keyed and then importing back in, etc. I've wondered what some of the tricks are to cut down on motion when keying; meaning when you get motion blur, the key falls apart. I'm trying to learn what can be done to minimize that other than not having the talent move hands too fast, etc. But my client is part Italian from New Jersey, so he talks using his hands a lot. But for things other than talking heads, such as jumping, dancing, etc. I'm guessing the more expensive your key program the better your results. Obviously Hollywood can accomplish very clean chroma-key but then I'm sure using 4:2:2 and big budgets helps a lot.

April 11th, 2009, 01:16 PM	#42
Leonard Levy Trustee Join Date: Feb 2006 Location: USA Posts: 1,684	Dean's discovery that he needed to blue up his fill is key (pun intended) to the kind of thinking you need to make it look natural. Match the light, (and the feeling of saturation which will come from how hard the light is) of the original scene as much as possible. Actually in Dean's shots I would suggest that perhaps a little cool bounce backlight or top light would be even closer to to matching how someone outside is lit because that same sky fill light is also hitting the tops and sides of the subject. Dean's shots look great though so its obviously not always neccessary. Sometimes the purpose of that that top or back light is to overwhelm reflection of the green screen in the subjects hair or clothes. That can be helped just by putting white or black cards around the green screen just out of shot to minimize the reflection. I used to always put my blue & green screens down at 40% in the BETA days, but had noise problems when I started using the HVX200. Jim Arthurs from Texas who's done lots of green screen with the EX and other cameras suggested raising it to 60%. I've been wary of 60 but switched to 55% after that. I think he still does his blue screens lower though. Jim was the first guy on these forums to rave about what a good key you could get with the EX-1 despite it being 4:2:0 Lenny Levy

April 11th, 2009, 01:27 PM	#43
Mitchell Lewis Trustee Join Date: Dec 2008 Location: Kennewick, WA Posts: 1,124	I recently did a chroma key test shoot shooting 1080 30p HQ. When the model was framed down to her waist only, the key looked great. But the client wanted to see the model walking from a distance toward the camera. Because the model was a short distance away, she was about 1/4 the size of the video frame. When I tried to get a good key on her at this distance, the edges didn't look that great (stair-stepped, pixelated). Having your model be as large as possible in the frame really helps you get a good quality key. Anyone have any experience using the EX1/EX3 chroma key for a "virtual set" where the model is at a greater distance to the camera? __________________ Sony EX3, Canon 5D MkII, Chrosziel Matte Box, Sachtler tripod, Steadicam Flyer, Mac Pro, Apple/Adobe software - 20 years as a local videographer/editor

April 11th, 2009, 02:41 PM	#44
Kenn Christenson Regular Crew Join Date: Oct 2003 Location: Medford Oregon Posts: 152	If you're getting a full-body shot - try mounting the camera sideways (portrait mode) to get the maximum amount of pixels dedicated to your subject.

April 11th, 2009, 02:45 PM	#45
Mitchell Lewis Trustee Join Date: Dec 2008 Location: Kennewick, WA Posts: 1,124	Whoa! How do you guys come up with this stuff? I never would have thought of that. Thanks Kenn. Now I just have to figure out how to mount the camera sideways! :) __________________ Sony EX3, Canon 5D MkII, Chrosziel Matte Box, Sachtler tripod, Steadicam Flyer, Mac Pro, Apple/Adobe software - 20 years as a local videographer/editor