Another White Balance Observation

Tom Roper · January 10th, 2009, 07:13 PM

On my EX1, B is set to ATW (which I seldom use)
A is what I manually white balance with a card,
and Preset is what I dial in from the picture profile.

As I understand, A performs the green/magenta correction, Preset does not.

When I go outside at dusk, this time of year in Denver, and white balance on a card, it comes up as 20,000 kelvin, which seems slightly yellow.

If I set the Preset from the picture profile I can't go above 10,000k and it looks magenta.

Tuomas Sebastien · January 11th, 2009, 01:55 AM

You can use color matrix in presets to fix green/magenta

Tom Roper · January 11th, 2009, 09:39 AM

Quote:

Originally Posted by Tuomas Sebastien

You can use color matrix in presets to fix green/magenta

Thanks, I could do that in post as well. Any thoughts on the "White Shading" inside the maintenance menu?

Alister Chapman · January 11th, 2009, 10:35 AM

White Shading corrects for hot spots or uneven exposure and require very careful setup. It has no effect on white balance.

Tom Roper · January 11th, 2009, 12:36 PM

Thanks. I'm leaning toward not making the adjustment on the color matrix Tuomas mentioned because I think it's correct where it stands under normal lighting conditions. Could the magenta push on the preset setting be happening because I can't manually dial the temperature above 10,000k? Is 20,000k under the white card balance unusual for evening shadows? Since I can't go above 10,000k dialing the temperature manually, could doing an offset in the picture profile for a white card balance be helpful? Maybe using an offset for the manual temperature setting could compensate for the magenta. I didn't think of that, but the confusion arises because the scaling of the offset is +/-99 arbitrary units whereas the temperature setting is absolute degrees kelvin, so trying to make this compensation from the flip out LCD is not likely to be satisfactory.

January 10th, 2009, 07:13 PM	#1
Tom Roper Trustee Join Date: Jun 2004 Location: Denver, Colorado Posts: 1,891	Another White Balance Observation - What should I do? On my EX1, B is set to ATW (which I seldom use) A is what I manually white balance with a card, and Preset is what I dial in from the picture profile. As I understand, A performs the green/magenta correction, Preset does not. When I go outside at dusk, this time of year in Denver, and white balance on a card, it comes up as 20,000 kelvin, which seems slightly yellow. If I set the Preset from the picture profile I can't go above 10,000k and it looks magenta.

January 11th, 2009, 10:35 AM	#4
Alister Chapman Inner Circle Join Date: Dec 2005 Location: Bracknell, Berkshire, UK Posts: 4,957	White Shading corrects for hot spots or uneven exposure and require very careful setup. It has no effect on white balance. __________________ Alister Chapman, Film-Maker/Stormchaser http://www.xdcam-user.com/alisters-blog/ My XDCAM site and blog. http://www.hurricane-rig.com

January 11th, 2009, 01:55 AM	#2
Tuomas Sebastien Regular Crew Join Date: Nov 2007 Location: Finland Posts: 107	You can use color matrix in presets to fix green/magenta

January 11th, 2009, 12:36 PM	#5
Tom Roper Trustee Join Date: Jun 2004 Location: Denver, Colorado Posts: 1,891	Thanks. I'm leaning toward not making the adjustment on the color matrix Tuomas mentioned because I think it's correct where it stands under normal lighting conditions. Could the magenta push on the preset setting be happening because I can't manually dial the temperature above 10,000k? Is 20,000k under the white card balance unusual for evening shadows? Since I can't go above 10,000k dialing the temperature manually, could doing an offset in the picture profile for a white card balance be helpful? Maybe using an offset for the manual temperature setting could compensate for the magenta. I didn't think of that, but the confusion arises because the scaling of the offset is +/-99 arbitrary units whereas the temperature setting is absolute degrees kelvin, so trying to make this compensation from the flip out LCD is not likely to be satisfactory.