White balance question

Mitchell Lewis · February 22nd, 2009, 08:45 PM

Okay, so here's another dumb question. What's the difference between:

A) White balancing on a warm card
B) White balancing on a white card, noting the color temp, entering it into your preset, and then adjusting the color temp to slightly warm up your shot

David C. Williams · February 22nd, 2009, 09:38 PM

White balance affects red, green and blue channels, so balancing on a green card effectively removes some green from your image. You can't do that at all or as quickly on most cameras.

Dean Sensui · February 23rd, 2009, 03:53 PM

Quote:

Originally Posted by Clark Peters

I have been told to use a Kodak gray card to white balance (the gray side, not the white side).

So far, it seems to work. Is there a problem I should be looking for?

Pete

A grey card is basically a darker version of a white card. You can do a white balance on it since it's neutral, and that's what important.

If you open a few stops, the grey card is white. If you close down a few stops, a white card is grey.

Personally, I use presets as much as possible for the sake of consistency. 5500k for daylight. 3200k for tungsten. I do the final correction in post.

Timothy R. Barksdale · April 9th, 2009, 08:51 PM

You've already received the correct advice, but buried in this are a few misleading suggestions... !

Under some circumstances using the un-calibrated warm cards can lead one into disaster.

I recommend that if you try to use the warm cards without a calibrated reference monitor you May not be happy with the final results. Blacks can get crushed and unless you are able to plan to reshoot, stick to either 100 IRE White or Neutral Gray. Always try to use clean white lights if indoors or natural light if outdoors. Fill your frame with as much of the lit card for your best white balance.

If you are doing evening shooting I try to get my final white of the day a few hours before sunset and then hold that setting. Your results will show you why I do this.

Tim Barksdale
D.P. Birdman Productions

Max Allen · April 9th, 2009, 09:56 PM

Quote:

Originally Posted by Serena Steuart

Distance doesn't affect the light..

Hi,

Take a color meter and measure a light's temperature at 2 feet then at 15 feet. You'll get different readings.

Regarding others' advice to rely on presets. For stage lighting, if there are spotlights, that should be your fallback instead of the primary solution. Spots range from 48k to over 6k.

For Stage lighting, a couple of answers from the LD will map out your approach.

1. Are there spotlights.
2. Is there a stage wash.
3. Between 1 & 2 what is corrected to what, or is there no correction (in which case the tools are; switch WB mid shoot/PProfile, ATW or WB to a median temp... depends on your shots and the degree of variance in source temperatures)

If there are no uncorrected Spots and keys are Lekos or PARs, 32k preset is fine. If keys are VLs (varilights) ask for white from the VLs and WB to that or try 56k preset -- this is again a fallback.

On cards, I'd recommend DSC Truewhite rather than Vortex and all other cards out there. More accurate. Nothing against Vortex, just ordered Doug's EX1 Field Guide. I would not recommend any warm cards. Warm cards should never have been invented for a host of reasons. Modify color in camera. That said, in a pinch whatever works, works. Someone convinced DSC to make a warm card too and later they admitted this mistake.

I also came across an old post I made on this 5 yrs ago:

http://www.dvinfo.net/conf/panasonic...procedure.html

Have a good shoot.

Anthony Lovell · April 10th, 2009, 02:46 PM

Quote:

Originally Posted by Brian Barkley

I use Warm Cards for all color (white) balancing. NEVER just pickup a piece of white paper or use someone's white clothing unless it is an emergency and you have no choice.
Warm Cards are pricey, but they will affect everything you shoot from this day forward, and for the rest of your career. I consider them a must . . . I have not white balanced from a white surface for a very long time. I will never go back to white balancing with a white card.
Vortex Media: VIDEO & PHOTO Tools and Training

I am glad to hear of someone else using these, as I have a set and use them as a totem to offset my inexperience.

I have recently kitted up my equipment to be a core set of equipment and "everything else". The warm-cards are in the core set so I cannot be anywhere without them unless I've mis-packed. Without having extensively practiced to see the results, I use the Warm 1/2 card as a minimal step toward a warmer-than-white scene. There are 2 cards colored more aggressively to skew your scene in the direction advertised.

edit: troubled by the follow-up answers. Maybe I have more to learn!

tone

Dean Sensui · April 10th, 2009, 03:01 PM

I always set my camera's white balance to get a neutral tone. The exceptions are sunrise and sunset, and night shots when there's several light sources.

Having done lots of color work, both in print and in broadcast, I prefer having a clean starting point, then skewing it as needed. It's much easier to do that than having to unskew something that's been shot with an in-camera effect, or dealing with material someone else might have tried to fix with an uncalibrated monitor.

At least one cameraman I know shoots with RED, records the raw image data off the imager, and sets the white balance in post. It sounds like a lousy workflow but it actually makes a lot of sense if the camera is capturing the raw imager data. In fact, it's probably the most flexible and future-proof way of doing things for now.

Mitchell Lewis · April 10th, 2009, 03:09 PM

Maybe I'm doing something wrong, but I can't remember the last time I white balanced a camera. If I'm using my tungsten lights, then I preset for 3200. If I'm outdoors, then I set for 5600. Fluorescents 4100. The only time I white balance is if the light is different from one of those (sunrise, sunset, gymnasium lights, etc...) If my color is slightly off, it's easy to fix in post. Final Cut Pro = 3-Way Color Corrector or Apple Color. After Effects = Color Finesse. I'm a little red/green color blind and using this technique, I still get compliments on how good my footage looks, so I must be doing something right. :)

Doug Jensen · April 10th, 2009, 06:58 PM

Quote:

Originally Posted by Timothy R. Barksdale

I recommend that if you try to use the warm cards without a calibrated reference monitor you May not be happy with the final results. Blacks can get crushed

As the owner of Vortex Media and the creator of WarmCards, I can assure you that white balancing on WarmCards (or anything else) cannot crush the blacks. White balance has nothing to do with anything except color tones. I am not sure where you heard that, or thought you saw it happen, but I assure you that it is untrue. In fact, this is the first time I have ever even heard it suggested.

Also, I suggest that people experiment with the cards when they first get them using a monitor so that they get a feel for how they work with THEIR camera, but after that, using a monitor is no more or less necessary than any other shooting situation. I use them 100% of the time and rarely use a monitor unless I'm shooting a formal sit-down interview or on-camera talent.

WarmCards are a simple way of achieving a conistently warmer white balance and than trying to monkey around with the offset white function of the EX1 and EX3.

I have shot nothing in the past 8 years that wasn't first custom white balanced with one of the WarmCards. 24,000 cameramen worldwide (including 60 Minutes, 20/20, BBC, CNN, NFL Films, ESPN, etc. can't be wrong. :-)

Max Allen · April 10th, 2009, 11:49 PM

Howdy Doug. Thanks for making some of the useful tools to help us all out. I have some further thoughts to share on this topic.

Millions of pros also use tungsten instead of HMI despite tungsten's flicker and reduced dynamic range. TV set manufacturers also abandoned the global D65 white reference in favor of brighter phosphors pushing white on end user sets to 9k. And CCDs also capture and TVs display RGB but studios and transmission process YPbPr causing legal and illegal levels crossing into each other. All of these practices are technically not ideal but it's the way things are because of economics.

If we were to consider the fundamentals, camera technology up to this point will never give you as good an image white balancing to any white card vs. having the camera manually aligned to a greyscale. WB is a cheap and dirty way to fall in the general area of what is visually acceptable. The crave for the warm card look is partly due to the inherent reflectance curve error of all white cards dipping so low after 5k in the spectrum, thus producing a blue image. If you think you don't see blue after WB, consider perceptual color and 'white' adaptation vs. the gamma readings on a scope. A warm card is then creating two wrongs to make a right. Some engineers will tell you it's better to warm the image in post. I don't necessarily agree with this unless you're shooting RAW as with RED. Any good engineer, however, will dissaprove of using a warm card. That said, a warm card is just another tool and useful in some situations but one that should be understood like any other tool. It is by no means the best tool for the intended result.

Back to white cards, again another flawed tool but nonetheless necessary due to economics and time. Personally, I'd prefer to know the reflectance curve of a white card and its spectrophotometer reading to see what I'm paying for vs. laminating card stock myself from the local art shop. A card appearing white to the eye may not have uniformity through the entire visible spectrum, with peaks and spikes at different points in addition to the blue shift. The difference between a card manufactured with tolerances and one that isn't is better overall image tonality, especially in skin tones. If you're shooting breaking news it's not the primary thought. If you're shooting a feature, commercial, high end newsmagazine... it is a concern. But then I'd hope there is a DIT.

Regarding the RED camera and leaving everything to post mentioned earlier. Compared to other video cams RED captures everything, making this possible. Other cameras record whatever you program the boards and DSP to capture. If highlights are clipping, shadows are undersaturated and blacks are void of detail and you're relying on factory default presets all around, footage will not be salvageable in post anywhere near the level that it would be with RED footage. It's also optically more pure I'd say to create the image to a nominal degree in camera vs. post processing.

Anyhow these are just some thoughts if anyone finds them interesting.

February 22nd, 2009, 08:45 PM	#16
Mitchell Lewis Trustee Join Date: Dec 2008 Location: Kennewick, WA Posts: 1,124	Okay, so here's another dumb question. What's the difference between: A) White balancing on a warm card B) White balancing on a white card, noting the color temp, entering it into your preset, and then adjusting the color temp to slightly warm up your shot __________________ Sony EX3, Canon 5D MkII, Chrosziel Matte Box, Sachtler tripod, Steadicam Flyer, Mac Pro, Apple/Adobe software - 20 years as a local videographer/editor

February 22nd, 2009, 09:38 PM	#17
David C. Williams Major Player Join Date: Jun 2008 Location: melb.vic.au Posts: 447	White balance affects red, green and blue channels, so balancing on a green card effectively removes some green from your image. You can't do that at all or as quickly on most cameras. __________________ www.davidwilliams.com.au

April 9th, 2009, 08:51 PM	#19
Timothy R. Barksdale New Boot Join Date: Jan 2006 Posts: 16	Warm Card warning You've already received the correct advice, but buried in this are a few misleading suggestions... ! Under some circumstances using the un-calibrated warm cards can lead one into disaster. I recommend that if you try to use the warm cards without a calibrated reference monitor you May not be happy with the final results. Blacks can get crushed and unless you are able to plan to reshoot, stick to either 100 IRE White or Neutral Gray. Always try to use clean white lights if indoors or natural light if outdoors. Fill your frame with as much of the lit card for your best white balance. If you are doing evening shooting I try to get my final white of the day a few hours before sunset and then hold that setting. Your results will show you why I do this. Tim Barksdale D.P. Birdman Productions

April 10th, 2009, 03:01 PM	#22
Dean Sensui Inner Circle Join Date: Oct 2001 Location: Honolulu, HI Posts: 2,054	I always set my camera's white balance to get a neutral tone. The exceptions are sunrise and sunset, and night shots when there's several light sources. Having done lots of color work, both in print and in broadcast, I prefer having a clean starting point, then skewing it as needed. It's much easier to do that than having to unskew something that's been shot with an in-camera effect, or dealing with material someone else might have tried to fix with an uncalibrated monitor. At least one cameraman I know shoots with RED, records the raw image data off the imager, and sets the white balance in post. It sounds like a lousy workflow but it actually makes a lot of sense if the camera is capturing the raw imager data. In fact, it's probably the most flexible and future-proof way of doing things for now. __________________ Dean Sensui Exec Producer, Hawaii Goes Fishing

April 10th, 2009, 03:09 PM	#23
Mitchell Lewis Trustee Join Date: Dec 2008 Location: Kennewick, WA Posts: 1,124	Maybe I'm doing something wrong, but I can't remember the last time I white balanced a camera. If I'm using my tungsten lights, then I preset for 3200. If I'm outdoors, then I set for 5600. Fluorescents 4100. The only time I white balance is if the light is different from one of those (sunrise, sunset, gymnasium lights, etc...) If my color is slightly off, it's easy to fix in post. Final Cut Pro = 3-Way Color Corrector or Apple Color. After Effects = Color Finesse. I'm a little red/green color blind and using this technique, I still get compliments on how good my footage looks, so I must be doing something right. :) __________________ Sony EX3, Canon 5D MkII, Chrosziel Matte Box, Sachtler tripod, Steadicam Flyer, Mac Pro, Apple/Adobe software - 20 years as a local videographer/editor

April 10th, 2009, 11:49 PM	#25
Max Allen Regular Crew Join Date: Mar 2004 Location: NY Posts: 186	Howdy Doug. Thanks for making some of the useful tools to help us all out. I have some further thoughts to share on this topic. Millions of pros also use tungsten instead of HMI despite tungsten's flicker and reduced dynamic range. TV set manufacturers also abandoned the global D65 white reference in favor of brighter phosphors pushing white on end user sets to 9k. And CCDs also capture and TVs display RGB but studios and transmission process YPbPr causing legal and illegal levels crossing into each other. All of these practices are technically not ideal but it's the way things are because of economics. If we were to consider the fundamentals, camera technology up to this point will never give you as good an image white balancing to any white card vs. having the camera manually aligned to a greyscale. WB is a cheap and dirty way to fall in the general area of what is visually acceptable. The crave for the warm card look is partly due to the inherent reflectance curve error of all white cards dipping so low after 5k in the spectrum, thus producing a blue image. If you think you don't see blue after WB, consider perceptual color and 'white' adaptation vs. the gamma readings on a scope. A warm card is then creating two wrongs to make a right. Some engineers will tell you it's better to warm the image in post. I don't necessarily agree with this unless you're shooting RAW as with RED. Any good engineer, however, will dissaprove of using a warm card. That said, a warm card is just another tool and useful in some situations but one that should be understood like any other tool. It is by no means the best tool for the intended result. Back to white cards, again another flawed tool but nonetheless necessary due to economics and time. Personally, I'd prefer to know the reflectance curve of a white card and its spectrophotometer reading to see what I'm paying for vs. laminating card stock myself from the local art shop. A card appearing white to the eye may not have uniformity through the entire visible spectrum, with peaks and spikes at different points in addition to the blue shift. The difference between a card manufactured with tolerances and one that isn't is better overall image tonality, especially in skin tones. If you're shooting breaking news it's not the primary thought. If you're shooting a feature, commercial, high end newsmagazine... it is a concern. But then I'd hope there is a DIT. Regarding the RED camera and leaving everything to post mentioned earlier. Compared to other video cams RED captures everything, making this possible. Other cameras record whatever you program the boards and DSP to capture. If highlights are clipping, shadows are undersaturated and blacks are void of detail and you're relying on factory default presets all around, footage will not be salvageable in post anywhere near the level that it would be with RED footage. It's also optically more pure I'd say to create the image to a nominal degree in camera vs. post processing. Anyhow these are just some thoughts if anyone finds them interesting.