White Balance Issue with XL-1

Charles Papert · March 22nd, 2002, 07:17 AM

Greg:

The Jungle Book does not have theatrical colors like the standard Rosco book, it's much slimmer and has primarily color correction and diffusion represented. Thus a theatrical supply company may not have it, but you may be able to have a film/video lighting supply house send you one.

CTO refers to the entire range of orange gels (Color Temperature Orange) for daylight to tungsten correction, and CTB to the blue gels. Thus the proper designation is 1/4 CTB, but is usually abbreviated to 1/4 blue.

As I'm sure is noted somewhere in the forum, Sony cameras tend towards the green as it increases apparent sharpness, but correcting out the green by using either a 1/8 or 1/4 green will substantially improve the skintones. This could also be done in color correction. Once you have made the correction, it is shocking to compare and realize just how green the standard Sony settings are! The Canon standard is much closer out of the box.

fargograf--yes, there are color temperature meters. Minolta makes the most popular. They provide a readout in degrees kelvin, and also designate the mired shift (which indicates how many points of magenta or green are present). It makes it easy to match all your lights to each other or the ambient light. Video is MUCH more forgiving of this sort of thing than film--it is possible to shoot under standard fluorescents supplemented with uncorrected tungsten lighting and have it look OK on tape, whereas the same scene would render noticeably green on film.

Greg Matty · March 22nd, 2002, 11:45 AM

Billravens,

I just got my 18% gray card and it is very gray. I thought it would be more of an off-white but no matter, it is here.

I don't have my XL-1 in front of me right now so I can't test it to see how it works. I have always been under the impression that white balance had to be done with something close to white. Obviously that is not the case.

You mentioned adjusting a color setting by +1. Is that on the XL-1 or XL-1s?

Thanks.

Greg

Ken Tanaka · March 22nd, 2002, 11:55 AM

<< Greg: I have always been under the impression that white balance had to be done with something close to white. Obviously that is not the case. >>

Actually if you white balance against something other than a white or neutral gray you get some pretty funky results. Try it when you have some lab time.

Bill Ravens · March 22nd, 2002, 12:02 PM

Greg...

yes, to our eyes, 18% gray looks dark. It, in fact, reflects no color information to the light meter...no chroma...just luma. That is, of course, unless you light it with light that has chroma in it. Shaded sunlight works good, cloudy sky light works best. Beware of lighting it with reflected light off of a colored surface. Kentanaka is right...take care when cal-ing with colored surfaces. I have great results calibrating with this card.

Yes, I've got an XL1s. 18% gray is 50 IRE...right smack in the middle of the IRE range. Calibrating with white is like calibrating at 100% IRE.....a long ways to extrapolate when reading an image that probably AVERAGES 50-75 IRE. Skin tones, for example are 75 IRE.

Good luck.

Greg Matty · March 22nd, 2002, 01:37 PM

<<<-- Originally posted by billravens : Greg...

yes, to our eyes, 18% gray looks dark. It, in fact, reflects no color information to the light meter...no chroma...just luma. That is, of course, unless you light it with light that has chroma in it. Shaded sunlight works good, cloudy sky light works best. Beware of lighting it with reflected light off of a colored surface. Kentanaka is right...take care when cal-ing with colored surfaces. I have great results calibrating with this card.

Yes, I've got an XL1s. 18% gray is 50 IRE...right smack in the middle of the IRE range. Calibrating with white is like calibrating at 100% IRE.....a long ways to extrapolate when reading an image that probably AVERAGES 50-75 IRE. Skin tones, for example are 75 IRE.

Good luck. -->>>

Can you clarify the "+" setting you referred to earlier? Maybe it is an XL-1s only feature.

Greg Matty

Bill Ravens · March 22nd, 2002, 02:05 PM

yep....in the XL1s there is a color adjustment in the menu. It allows shifting the recorded image chroma(hue) to red(+) or green(-). This is in addition to the "white balance, which shifts the virtual center of the color wheel....where "white" is defined.

Bob Zimmerman · March 23rd, 2002, 08:34 AM

This thread has really helped on the white balance subject. How often do you white balance? Every scene or just when the lighting changes? Do you use the white balance when using a light on the camcorder?

Charles Papert · March 23rd, 2002, 01:16 PM

It's best to white balance often outside if the sun goes into clouds, as the overcast sky is much bluer than direct sun. Also, at the end of the day the ambient light changes significantly--the setting sun often gets much warmer before it goes down, then the twilight is extremely blue, so if you are looking to maintain continuity then frequent white balancing will help.

When using an on-camera light, it's a good idea to have use small gels of various strengths blue and orange that will help match it to the ambient light conditions. It's an odd look to have tunsten light in the foreground and daylight in the background, but one that is frequently seen on the evening news--unless that is the desired effect!

March 22nd, 2002, 07:17 AM	#16
Charles Papert Wrangler Join Date: Jan 2002 Location: Los Angeles, CA Posts: 6,810	Greg: The Jungle Book does not have theatrical colors like the standard Rosco book, it's much slimmer and has primarily color correction and diffusion represented. Thus a theatrical supply company may not have it, but you may be able to have a film/video lighting supply house send you one. CTO refers to the entire range of orange gels (Color Temperature Orange) for daylight to tungsten correction, and CTB to the blue gels. Thus the proper designation is 1/4 CTB, but is usually abbreviated to 1/4 blue. As I'm sure is noted somewhere in the forum, Sony cameras tend towards the green as it increases apparent sharpness, but correcting out the green by using either a 1/8 or 1/4 green will substantially improve the skintones. This could also be done in color correction. Once you have made the correction, it is shocking to compare and realize just how green the standard Sony settings are! The Canon standard is much closer out of the box. fargograf--yes, there are color temperature meters. Minolta makes the most popular. They provide a readout in degrees kelvin, and also designate the mired shift (which indicates how many points of magenta or green are present). It makes it easy to match all your lights to each other or the ambient light. Video is MUCH more forgiving of this sort of thing than film--it is possible to shoot under standard fluorescents supplemented with uncorrected tungsten lighting and have it look OK on tape, whereas the same scene would render noticeably green on film. __________________ Charles Papert www.charlespapert.com

March 22nd, 2002, 11:55 AM	#18
Ken Tanaka Retired DV Info Net Almunus Join Date: Dec 2001 Location: Chicago, IL Posts: 6,943	<< Greg: I have always been under the impression that white balance had to be done with something close to white. Obviously that is not the case. >> Actually if you white balance against something other than a white or neutral gray you get some pretty funky results. Try it when you have some lab time. __________________ Lady X Films: A lady with a boring wardrobe...and a global mission. Hey, you don't have enough stuff! Buy with confidence from our sponsors. Hand-picked as the best in the business...Really! See some of my work one frame at a time: www.KenTanaka.com

March 23rd, 2002, 01:16 PM	#23
Charles Papert Wrangler Join Date: Jan 2002 Location: Los Angeles, CA Posts: 6,810	It's best to white balance often outside if the sun goes into clouds, as the overcast sky is much bluer than direct sun. Also, at the end of the day the ambient light changes significantly--the setting sun often gets much warmer before it goes down, then the twilight is extremely blue, so if you are looking to maintain continuity then frequent white balancing will help. When using an on-camera light, it's a good idea to have use small gels of various strengths blue and orange that will help match it to the ambient light conditions. It's an odd look to have tunsten light in the foreground and daylight in the background, but one that is frequently seen on the evening news--unless that is the desired effect! __________________ Charles Papert www.charlespapert.com

March 22nd, 2002, 11:45 AM	#17
Greg Matty Regular Crew Join Date: Mar 2002 Location: Kirkland, WA Posts: 177	Billravens, I just got my 18% gray card and it is very gray. I thought it would be more of an off-white but no matter, it is here. I don't have my XL-1 in front of me right now so I can't test it to see how it works. I have always been under the impression that white balance had to be done with something close to white. Obviously that is not the case. You mentioned adjusting a color setting by +1. Is that on the XL-1 or XL-1s? Thanks. Greg

March 22nd, 2002, 12:02 PM	#19
Bill Ravens Join Date: Nov 2001 Location: santa fe, nm Posts: 3,264 Images: 10	Greg... yes, to our eyes, 18% gray looks dark. It, in fact, reflects no color information to the light meter...no chroma...just luma. That is, of course, unless you light it with light that has chroma in it. Shaded sunlight works good, cloudy sky light works best. Beware of lighting it with reflected light off of a colored surface. Kentanaka is right...take care when cal-ing with colored surfaces. I have great results calibrating with this card. Yes, I've got an XL1s. 18% gray is 50 IRE...right smack in the middle of the IRE range. Calibrating with white is like calibrating at 100% IRE.....a long ways to extrapolate when reading an image that probably AVERAGES 50-75 IRE. Skin tones, for example are 75 IRE. Good luck.

March 22nd, 2002, 01:37 PM	#20
Greg Matty Regular Crew Join Date: Mar 2002 Location: Kirkland, WA Posts: 177	<<<-- Originally posted by billravens : Greg... yes, to our eyes, 18% gray looks dark. It, in fact, reflects no color information to the light meter...no chroma...just luma. That is, of course, unless you light it with light that has chroma in it. Shaded sunlight works good, cloudy sky light works best. Beware of lighting it with reflected light off of a colored surface. Kentanaka is right...take care when cal-ing with colored surfaces. I have great results calibrating with this card. Yes, I've got an XL1s. 18% gray is 50 IRE...right smack in the middle of the IRE range. Calibrating with white is like calibrating at 100% IRE.....a long ways to extrapolate when reading an image that probably AVERAGES 50-75 IRE. Skin tones, for example are 75 IRE. Good luck. -->>> Can you clarify the "+" setting you referred to earlier? Maybe it is an XL-1s only feature. Greg Matty

March 22nd, 2002, 02:05 PM	#21
Bill Ravens Join Date: Nov 2001 Location: santa fe, nm Posts: 3,264 Images: 10	yep....in the XL1s there is a color adjustment in the menu. It allows shifting the recorded image chroma(hue) to red(+) or green(-). This is in addition to the "white balance, which shifts the virtual center of the color wheel....where "white" is defined.

March 23rd, 2002, 08:34 AM	#22
Bob Zimmerman Major Player Join Date: Nov 2001 Location: Illinois Posts: 888	This thread has really helped on the white balance subject. How often do you white balance? Every scene or just when the lighting changes? Do you use the white balance when using a light on the camcorder?