Green video in gym at DVinfo.net

Ethan Cooper · April 20th, 2008, 08:43 PM

Here's my little mystery:

We had a reception in a gym this weekend and no matter what I did to white balance 2 of my 3 cameras, both came out with a green cast or tint to their pictures. One was our trusty old VX2000 and the other was a HV20. Our FX7 was unaffected by the problem.
I started out with all cameras in auto white balance, but when it became apparent there was some sort of problem going on I tried to manually white balance both the VX and the HV20 on a table cloth to no avail. They both seemed to think the room was green no matter what I tried. The FX7 never read the light as green at any point.
I seem to think it has something to do with a particular type of lighting used in gyms, but I can't track it down and have no explanation for why it only affected 2 of 3 cameras. Anyone know what it is exactly and if there's something you can do about it. Better yet, do you have an explanation for why it would affect a VX2000 (3 chip CCD) and HV20 (1 chip CMOS) but not a FX7 (3 chip CMOS)?

Greg Boston · April 20th, 2008, 09:13 PM

Same thing happens with regular old fluorescent lighting. You have to have a minus green filter on the lens (or light source) that counteracts this effect.

The problem is that the light output has a more or less dual spike in the green spectrum. Another way to counteract this is with a custom color matrix in the camera. My F350, along with some other cameras, have this as a preset.

As to why the FX7 handled it better, I am as puzzled as you are.

-gb-

Ethan Cooper · April 20th, 2008, 10:26 PM

I've shot in a lot of lighting situations over the past 6 years and this is the first I've ever seen of the green cast I remember reading about with fluorescence. It's not a problem since I can always correct it in post, but I could see it being a major problem if you were doing a live broadcast or something like that and didn't have the proper on camera filtration or in camera settings.

Any good theory for why the FX7 came through unscathed?

Monday Isa · April 21st, 2008, 09:19 AM

It's a sign to get another one (^_^)

Ethan Cooper · April 21st, 2008, 09:22 AM

Funny. I'll get right on that.

Tim Harjo · April 26th, 2008, 12:33 AM

I'm frequently guilty of not doing a good white balance job before a shoot. I usually try one of the auto settings and go with the one that looks the best. I don't worry about it ever because I just fix it in post. not sure what you are using, but i use final cut Pro. I use the 3 color corrector. The one circe on the right adjusts for "whites". I simply move this until I like it.

On that note, I used to make the whites, well... white. Now I adjust it to give it more of a 'mood'. I love working with colors.

April 20th, 2008, 08:43 PM	#1
Ethan Cooper Trustee Join Date: Dec 2003 Location: Houma, La. Posts: 1,400 Images: 5	Green video in gym Here's my little mystery: We had a reception in a gym this weekend and no matter what I did to white balance 2 of my 3 cameras, both came out with a green cast or tint to their pictures. One was our trusty old VX2000 and the other was a HV20. Our FX7 was unaffected by the problem. I started out with all cameras in auto white balance, but when it became apparent there was some sort of problem going on I tried to manually white balance both the VX and the HV20 on a table cloth to no avail. They both seemed to think the room was green no matter what I tried. The FX7 never read the light as green at any point. I seem to think it has something to do with a particular type of lighting used in gyms, but I can't track it down and have no explanation for why it only affected 2 of 3 cameras. Anyone know what it is exactly and if there's something you can do about it. Better yet, do you have an explanation for why it would affect a VX2000 (3 chip CCD) and HV20 (1 chip CMOS) but not a FX7 (3 chip CMOS)? __________________ ∅ -Ethan Cooper

April 20th, 2008, 10:26 PM	#3
Ethan Cooper Trustee Join Date: Dec 2003 Location: Houma, La. Posts: 1,400 Images: 5	I've shot in a lot of lighting situations over the past 6 years and this is the first I've ever seen of the green cast I remember reading about with fluorescence. It's not a problem since I can always correct it in post, but I could see it being a major problem if you were doing a live broadcast or something like that and didn't have the proper on camera filtration or in camera settings. Any good theory for why the FX7 came through unscathed? __________________ ∅ -Ethan Cooper

April 21st, 2008, 09:22 AM	#5
Ethan Cooper Trustee Join Date: Dec 2003 Location: Houma, La. Posts: 1,400 Images: 5	Funny. I'll get right on that. __________________ ∅ -Ethan Cooper

April 20th, 2008, 09:13 PM	#2
Greg Boston Wrangler Join Date: Oct 2003 Location: DFW area, TX Posts: 6,117 Images: 1	Same thing happens with regular old fluorescent lighting. You have to have a minus green filter on the lens (or light source) that counteracts this effect. The problem is that the light output has a more or less dual spike in the green spectrum. Another way to counteract this is with a custom color matrix in the camera. My F350, along with some other cameras, have this as a preset. As to why the FX7 handled it better, I am as puzzled as you are. -gb-

April 21st, 2008, 09:19 AM	#4
Monday Isa Major Player Join Date: Mar 2006 Location: College Park, Maryland Posts: 913	It's a sign to get another one (^_^)

April 26th, 2008, 12:33 AM	#6
Tim Harjo Regular Crew Join Date: Dec 2003 Location: Sacramento, California Posts: 195	I'm frequently guilty of not doing a good white balance job before a shoot. I usually try one of the auto settings and go with the one that looks the best. I don't worry about it ever because I just fix it in post. not sure what you are using, but i use final cut Pro. I use the 3 color corrector. The one circe on the right adjusts for "whites". I simply move this until I like it. On that note, I used to make the whites, well... white. Now I adjust it to give it more of a 'mood'. I love working with colors.