Green fuzz on captured footage at DVinfo.net

Gibran Jimenez · December 2nd, 2009, 03:48 AM

Hello guys, hope you know about this problem... I am working on a regular dv sequence.. and notice that I get this fade of green in the top right half of the screen.

It looks like a distortion but really mechanical since it shows a border in the top half of footage.. i included a picture of this problem.. it is the green fade to disolve.

Any input is appreciated.
I have also seen this problem on HDV 30P footage as well. I thought it was a computer display problem but it actually makes it to DVD or YOUTUBE.

-JVC HD-100
-Captured using NTSC/DV 720x480 on a same setting sequence..

Ted Ramasola · December 2nd, 2009, 05:17 AM

Gibran,

Its seems you were shooting with existing light. Did you shoot this using stock lens at full open? Like f1.4-f1.8 ? If you did then its due to lateral CA on the stock lens. You can see this clearly when shooting on a gray or white wall. Go wide and full open. You'll see the green and magenta CA.

It starts going away at f2. Gone by f2.8.

Ted

Eric Deyerler · December 6th, 2009, 07:55 AM

it is not CA, it looks like a green flare in the top of the picture,
it can cause due to the light fall in the optic, when you use a greater
sunshade the problem will be solved.

Phil Balsdon · December 6th, 2009, 02:17 PM

It's from the fluorescent light tubes. Much of the scene is probably lit directly with the downlights (in the little round holes) which are tungsten. The lighting concealed higher up and reflecting off the ceiling is flourescent and has a green hue.

Back in film days a magenta or "negative green" gel was used to correct this.

It's not CA which occurs on contrasty edges and is a lens problem, there's nothing wrong with your camera.

Taylor Brush · December 7th, 2009, 02:40 PM

I second the fluorescent tubes theory. "Minus green" gels solve the problem. Secondary color correction with a digital grad filter probably will take care of it too.

Jay Webster · December 7th, 2009, 06:17 PM

Yup,
Taylor, Phil, Eric and Ted have nailed it. I do a series of tv commercials for a retail chain that just loves to shoot in their stores. had a similar problem first time out when lighting. Couldn't shut the entire store down, so, placed Tough minus green over the overhead flourescents and Whalaa! problem gone. Just check what types of flourescents you are dealing with and adjust you gel correction accordingly.

Cheers,
Jay Webster
NYC Director/Cameraman

Eric Deyerler · December 7th, 2009, 06:19 PM

The same green fuzz get a user with one of the first HM700.
I know it also in some lighting situations, but when you know it,
you can solve it

Gibran Jimenez · December 12th, 2009, 05:17 PM

This is the second time it happens.. The first time was also indoors with flourescent lights.. so basically a "minus green" is a gel that would be wrapped around a set of lights?

Thanks for all your responses,, i'll check more constantly next time.

Jay Webster · December 13th, 2009, 10:28 AM

The gel goes over the fluorescent light.

Jay Webster
NYC, NY

December 2nd, 2009, 03:48 AM	#1
Gibran Jimenez New Boot Join Date: Jan 2008 Location: Los Angeles, CA Posts: 9	Green fuzz on captured footage Hello guys, hope you know about this problem... I am working on a regular dv sequence.. and notice that I get this fade of green in the top right half of the screen. It looks like a distortion but really mechanical since it shows a border in the top half of footage.. i included a picture of this problem.. it is the green fade to disolve. Any input is appreciated. I have also seen this problem on HDV 30P footage as well. I thought it was a computer display problem but it actually makes it to DVD or YOUTUBE. -JVC HD-100 -Captured using NTSC/DV 720x480 on a same setting sequence.. Attached Thumbnails

December 12th, 2009, 05:17 PM	#8
Gibran Jimenez New Boot Join Date: Jan 2008 Location: Los Angeles, CA Posts: 9	Wow, thanks for the info... This is the second time it happens.. The first time was also indoors with flourescent lights.. so basically a "minus green" is a gel that would be wrapped around a set of lights? Thanks for all your responses,, i'll check more constantly next time.

December 13th, 2009, 10:28 AM	#9
Jay Webster Regular Crew Join Date: Feb 2006 Location: New York Posts: 131	Green fuzz The gel goes over the fluorescent light. Jay Webster NYC, NY

December 2nd, 2009, 05:17 AM	#2
Ted Ramasola Trustee Join Date: May 2005 Location: Allen, Texas U.S.A Posts: 1,117	Gibran, Its seems you were shooting with existing light. Did you shoot this using stock lens at full open? Like f1.4-f1.8 ? If you did then its due to lateral CA on the stock lens. You can see this clearly when shooting on a gray or white wall. Go wide and full open. You'll see the green and magenta CA. It starts going away at f2. Gone by f2.8. Ted

December 6th, 2009, 07:55 AM	#3
Eric Deyerler Regular Crew Join Date: May 2009 Location: Schwabach (Germany - Bavaria) Posts: 199	it is not CA, it looks like a green flare in the top of the picture, it can cause due to the light fall in the optic, when you use a greater sunshade the problem will be solved.

December 6th, 2009, 02:17 PM	#4
Phil Balsdon Regular Crew Join Date: May 2006 Location: Sydney, Australia Posts: 91	It's from the fluorescent light tubes. Much of the scene is probably lit directly with the downlights (in the little round holes) which are tungsten. The lighting concealed higher up and reflecting off the ceiling is flourescent and has a green hue. Back in film days a magenta or "negative green" gel was used to correct this. It's not CA which occurs on contrasty edges and is a lens problem, there's nothing wrong with your camera.

December 7th, 2009, 02:40 PM	#5
Taylor Brush Regular Crew Join Date: Mar 2008 Location: Jurbise, Belgium Posts: 29	I second the fluorescent tubes theory. "Minus green" gels solve the problem. Secondary color correction with a digital grad filter probably will take care of it too.

December 7th, 2009, 06:17 PM	#6
Jay Webster Regular Crew Join Date: Feb 2006 Location: New York Posts: 131	Yup, Taylor, Phil, Eric and Ted have nailed it. I do a series of tv commercials for a retail chain that just loves to shoot in their stores. had a similar problem first time out when lighting. Couldn't shut the entire store down, so, placed Tough minus green over the overhead flourescents and Whalaa! problem gone. Just check what types of flourescents you are dealing with and adjust you gel correction accordingly. Cheers, Jay Webster NYC Director/Cameraman

December 7th, 2009, 06:19 PM	#7
Eric Deyerler Regular Crew Join Date: May 2009 Location: Schwabach (Germany - Bavaria) Posts: 199	The same green fuzz get a user with one of the first HM700. I know it also in some lighting situations, but when you know it, you can solve it