White Balance with XL-2

Jonathan Ramsey · October 14th, 2004, 09:13 AM

Greg,

Here are some thoughts:
1. Check out getting some premade white balancing cards from warmcards.com. They have field sizes and studio sizes and I've had great results from these (but keep them in their case so that the sun doesn't fade them). Essentially, they offer a compact variety of increasingly cooler and warmer cards from which to white balance. In practice, that means if things are showing up cooler than you'd like, white balance on a slightly blue surface or on a white surface that has bluer light reflecting off of it. Your result will be a warmer look. This is all essentially tricking the camera into what you are saying is 5600K. Follow me?
2. So, without the cards, you can also do this. The old way was to hold up a guerilla book infront of the lens and do it. Pain in the hinney. A quick field shoot way to handle it, perhaps useful in the Pacific NW especially, is to white balance off of some clouds. They may appear white to your eye, but in fact they have loads of cool color temps bouncing in and around them and they will result in a warmer white balance. You just have to do it over and over until you get exactly what you'd want.
3. In Costa Rica, the light is very white, being so close to the equator. I shot there, too. So, you might have tried the cloud technique or you might have the person with the white shirt hold it up to point to the sky. Get on a rock or something and look down on it, that will warm it up even more. Better yet, go to warmcards.com and drop $65. I think they have minus green available, too (for flourescent lighting issues).

Does that help?

Ramsey

Greg Matty · October 14th, 2004, 10:06 PM

Ramsey,

Many thanks for the well thought out response.

I have the warm cards but have only ever used the minus 1/2 blue. I'll try the idea of the sky white balance the next I am shooting under the clouds.

With so many people puzzled as to why I have never gotten a good white balance, I am now convinced my XL-1 was defective.

Greg

Barry Goyette · October 15th, 2004, 09:16 AM

Greg.

I know what your saying. My xl1s was always balancing10-15% more yellow than it should be...some might like the warmth, but I always felt it was just inaccurate. My xl2, on the other hand seems dead neutral, even more so than the gl2, which I always felt had a better white balance than the xl1. I've found that if you white balance correctly and then up the color gain 1 or 2 notches, use cinegamma and cinematrix...you get a natural scene rendering with baywatch skin tones...something the xl1s would never do. If you want a more filtered look, then start tweaking the individual color channels (similar to the controls on the DVX).

Barry

A. J. deLange · October 16th, 2004, 11:17 AM

It's relatively simple to check the white balance on your camera. You need something that is neutral to do it with. A grey card is fine as long as it is a new one of good quality and you light it flatly. An Expodisc, a device which fits over the lens with neutral transmission (calibration data is included with it) is ideal and a bright white coffee filter will serve as well. Fix Epodisk or coffee filter (coffee filters have been reported as being neutral and the one brand I have checked is but this does not guarantee that the one you buy will be) over the lens, point at the light source you are interested in and push the balance button. After the balance operation is complete, capture a frame and open it in Photoshop. Be sure to indicate to Photoshop that the source was from NTSC space. Now use the eyedropper to examine the uniformly gray field using the Lab slider option for the color info. If the camera, disk and balance algortihms were perfect you would read the same luminance everywhere in the frame and a and b would both be equal to 0. In reality you will find (or at least I found with my camera) that there are lots of regions where you read (use 5 x 5 pixel averaging) 0,0 but there are others where you'll get pairs like (0,1), (-2,0), (-1,1), (1,0) and so on. Take the square root of the sum of the squares of a and b. Where this is 1 or less (pairs with two zeros or a zero and a 1) the color is considered identically neutral. Where this is 3 or less (e.g. 2,1 or 2,2) the color is considered indistinguishable from gray. On my camera I find that the colors are indistinguishable from gray until I get out to the corners of the picture where I suspect the Expodisc is vignetting because the luminance is dropping off there too.

Thus I conclude that my camera does a very good job indeed of setting white balance. If you do this experiment and get a similar result don't fault the camera if you don't like the color balance. It is doing what it is supposed to do. If you consider the result too warm or too cool that is because your taste or preference is different from what the camera provides which is true neutrality. Tweak the color settings until you get what you want. This is not a reflection upon your taste. De gustibus non disputandem est!

A.J.

Clayton Hairs · November 4th, 2004, 04:26 AM

I remember having this sort of problem when I originally bought the XL1 (about six/seven years back - I"m now a committed XL2 freak...without the troubles you're having I might add)...is there any chance your camera might've got damp while shooting - I remember shooting in mist in South Africa when I first got the XL1 and somehow this had got back to the CCD's and the white balance would run rabid as a banshee...ok maybe that's an exaggeration but it didn't behave itself as it should've...

Lauri Kettunen · November 4th, 2004, 08:01 AM

By experimenting with my Xl1 I found that it was often useful not to focus on the white card when adjusting the white balance. The out of focus creates a kind of averaging process A.J mentioned about in his post.

In my experience Xl2 is indeed more accurate in setting the white balance than Xl1 although never had significant problems with the Xl1. I notice the difference now especially when filming sunrise of sunset. The color tone on video is very close to what I observe by eye; This is something which I never quite managed to end up with the Xl1 (or with a Sony Betacam camcorder before the Xl1).

David Clark · November 4th, 2004, 11:18 AM

Hi, have you tried using one of those "Shooters Blues" white card from e-bay. Should warm up the color a bit.

October 14th, 2004, 09:13 AM	#16
Jonathan Ramsey Regular Crew Join Date: Sep 2004 Location: Colorado Posts: 32	Greg, Here are some thoughts: 1. Check out getting some premade white balancing cards from warmcards.com. They have field sizes and studio sizes and I've had great results from these (but keep them in their case so that the sun doesn't fade them). Essentially, they offer a compact variety of increasingly cooler and warmer cards from which to white balance. In practice, that means if things are showing up cooler than you'd like, white balance on a slightly blue surface or on a white surface that has bluer light reflecting off of it. Your result will be a warmer look. This is all essentially tricking the camera into what you are saying is 5600K. Follow me? 2. So, without the cards, you can also do this. The old way was to hold up a guerilla book infront of the lens and do it. Pain in the hinney. A quick field shoot way to handle it, perhaps useful in the Pacific NW especially, is to white balance off of some clouds. They may appear white to your eye, but in fact they have loads of cool color temps bouncing in and around them and they will result in a warmer white balance. You just have to do it over and over until you get exactly what you'd want. 3. In Costa Rica, the light is very white, being so close to the equator. I shot there, too. So, you might have tried the cloud technique or you might have the person with the white shirt hold it up to point to the sky. Get on a rock or something and look down on it, that will warm it up even more. Better yet, go to warmcards.com and drop $65. I think they have minus green available, too (for flourescent lighting issues). Does that help? Ramsey __________________ Jonathan Ramsey director/producer treeline film company colorado

October 14th, 2004, 10:06 PM	#17
Greg Matty Regular Crew Join Date: Mar 2002 Location: Kirkland, WA Posts: 177	Ramsey, Many thanks for the well thought out response. I have the warm cards but have only ever used the minus 1/2 blue. I'll try the idea of the sky white balance the next I am shooting under the clouds. With so many people puzzled as to why I have never gotten a good white balance, I am now convinced my XL-1 was defective. Greg

October 15th, 2004, 09:16 AM	#18
Barry Goyette Trustee Join Date: Oct 2001 Location: San Luis Obispo CA Posts: 1,195	Greg. I know what your saying. My xl1s was always balancing10-15% more yellow than it should be...some might like the warmth, but I always felt it was just inaccurate. My xl2, on the other hand seems dead neutral, even more so than the gl2, which I always felt had a better white balance than the xl1. I've found that if you white balance correctly and then up the color gain 1 or 2 notches, use cinegamma and cinematrix...you get a natural scene rendering with baywatch skin tones...something the xl1s would never do. If you want a more filtered look, then start tweaking the individual color channels (similar to the controls on the DVX). Barry

October 16th, 2004, 11:17 AM	#19
A. J. deLange Major Player Join Date: Jun 2004 Location: McLean, VA United States Posts: 749	It's relatively simple to check the white balance on your camera. You need something that is neutral to do it with. A grey card is fine as long as it is a new one of good quality and you light it flatly. An Expodisc, a device which fits over the lens with neutral transmission (calibration data is included with it) is ideal and a bright white coffee filter will serve as well. Fix Epodisk or coffee filter (coffee filters have been reported as being neutral and the one brand I have checked is but this does not guarantee that the one you buy will be) over the lens, point at the light source you are interested in and push the balance button. After the balance operation is complete, capture a frame and open it in Photoshop. Be sure to indicate to Photoshop that the source was from NTSC space. Now use the eyedropper to examine the uniformly gray field using the Lab slider option for the color info. If the camera, disk and balance algortihms were perfect you would read the same luminance everywhere in the frame and a and b would both be equal to 0. In reality you will find (or at least I found with my camera) that there are lots of regions where you read (use 5 x 5 pixel averaging) 0,0 but there are others where you'll get pairs like (0,1), (-2,0), (-1,1), (1,0) and so on. Take the square root of the sum of the squares of a and b. Where this is 1 or less (pairs with two zeros or a zero and a 1) the color is considered identically neutral. Where this is 3 or less (e.g. 2,1 or 2,2) the color is considered indistinguishable from gray. On my camera I find that the colors are indistinguishable from gray until I get out to the corners of the picture where I suspect the Expodisc is vignetting because the luminance is dropping off there too. Thus I conclude that my camera does a very good job indeed of setting white balance. If you do this experiment and get a similar result don't fault the camera if you don't like the color balance. It is doing what it is supposed to do. If you consider the result too warm or too cool that is because your taste or preference is different from what the camera provides which is true neutrality. Tweak the color settings until you get what you want. This is not a reflection upon your taste. De gustibus non disputandem est! A.J.

November 4th, 2004, 04:26 AM	#20
Clayton Hairs New Boot Join Date: Nov 2004 Location: London, UK Posts: 12	I remember having this sort of problem when I originally bought the XL1 (about six/seven years back - I"m now a committed XL2 freak...without the troubles you're having I might add)...is there any chance your camera might've got damp while shooting - I remember shooting in mist in South Africa when I first got the XL1 and somehow this had got back to the CCD's and the white balance would run rabid as a banshee...ok maybe that's an exaggeration but it didn't behave itself as it should've...

November 4th, 2004, 08:01 AM	#21
Lauri Kettunen Major Player Join Date: Aug 2004 Location: Kangasala, Finland Posts: 445	By experimenting with my Xl1 I found that it was often useful not to focus on the white card when adjusting the white balance. The out of focus creates a kind of averaging process A.J mentioned about in his post. In my experience Xl2 is indeed more accurate in setting the white balance than Xl1 although never had significant problems with the Xl1. I notice the difference now especially when filming sunrise of sunset. The color tone on video is very close to what I observe by eye; This is something which I never quite managed to end up with the Xl1 (or with a Sony Betacam camcorder before the Xl1).

November 4th, 2004, 11:18 AM	#22
David Clark Regular Crew Join Date: Mar 2004 Location: Carrollton, Texas Posts: 145	Hi, have you tried using one of those "Shooters Blues" white card from e-bay. Should warm up the color a bit.