White balance

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DanHD

Well-known member
I'm having a hard time understanding white balance and how it correlates to lighting temperature, ect.

I mean, if I light a room with tungsten lights, and I want it to look tungsten, is the white balance going to try to make it look like daylight?

and visa versa?

I just dont get it
 
What is the difference between white balancing, and adding a certain color of light?

Totally naive question, I know.
 
Hi Dan,
Your 2 post indicate you are under the wrong impression that 'white balancing' is an attempt to describe color to a camcorder.
White balancing is an attempt to tell the camcorder 'what is white'.
Once camcorder recognizes what is white under that certain light, it produces all other colors accordingly.
To answer your first question: if you use tungsten light, and do a white balance accordingly what you gonna get is not daylight look, but a very similar look to what you are seeing with your eyes on that room.
If you want a warmer look in this set up, simply do your white balance with a slightly blueish card...
There are many aspects to this subject, i just wanted to describe some basics...
 
3200k light balanced @ 3200k = "white" light
5600k light balanced @ 5600k = "white" light
5600k light balanced @ 3200k = blue light
3200k light balanced @ 5600k = warm light

etc, etc. for the entire spectrum in between.
 
WB refers to the color spectrum of the dominant light source. In the old days we changed film stock - now we WB electronically.

WB balance on your camera also corrects for mired shift (green/magenta), something no film-stock could do.

Ignore people who tell you to WB every shot - that is rarely helpful advice
 
DanHD said:
WHy would it not be alright to white balance more frequently?
Click to expand...

White balance every time you change lighting quality... You could otherwise introduce 'shifts' in a sequence of takes, which may disallow the results to be 'easily' edited together, with out post-production balancing. As I recall the 'balancing in camera' is done before compression, so, the 'full' values are used for to shift the relationships between RGB. When this is done after compression, because the compression is 'lossy' the shifting may not be as good.

While in theory, for the same light value, successive white balances should result in the same values for removing a color cast... things often in practice are different...
 
DanHD said:
What is the difference between white balancing, and adding a certain color of light?

Totally naive question, I know.
Click to expand...

As people have said, you white balance to tell the camera what white is in the shot.

So if you want to compliment the WB with colored light - WB for the dominant light and then use colored gels on your fixtures to add your splashes of color.

DanHD said:
WHy would it not be alright to white balance more frequently?
Click to expand...

It depends on what you are shooting. But a couple of examples would be:

Shooting a narrative scene where the lighting is controlled - you set WB (and this doesnt have to be a WB to true WB - you can set it to taste), but once you set it for a particular scene, you most likely would want to ensure it remains uniform for the whole scene.

Its important to note your WB, as you may come to another scene in the same room, thats meant to be the same time of day etc and may want to return to the same settings you used in previous.

Another example is on an exterior shot where you WB to 5600K for daylight, but want to then shoot the golden hues of the sun setting etc. You would most likely want to stay on 5600k to ensure those hues are golden. Redoing a WB would mean a color shift away from that.

I use the words "most likely" here as its all subjective to taste and what you want in feel etc．

Another example would be an interview, see my first point about narrative scene, same thing applies. Again apply "most likely".

I think its becoming more common these days (in the digital world) to do a true WB, and do color changes in post.
 
Still dont totally understand it.



I mean, if I'm shooting a scene where I want tungsten to LOOK tungsten, is the WB going to try to make it look white?
 
DanHD said:
Still dont totally understand it.

I mean, if I'm shooting a scene where I want tungsten to LOOK tungsten, is the WB going to try to make it look white?
Click to expand...

Okay, the most direct explanations I can think of to this specific question:

- If you have a purely white surface in front of the camera, in the same light that the scene will be shot in, and you white balance the camera based on that, the camera will take that white surface, and try to calibrate it to see pure white. Everything else will adjust accordingly.

- So if you're in very warm lighting, it will compensate and cool colors a bit to neutralize the color temperature.

- If you're in very cool lighting, it will compensate and warm colors a bit to neutralize the color temperature.

DON'T THINK OF IT SO MUCH AS WHITE, BUT AS GRAY, AND "WHITE BALANCING" IS THE CAMERA'S WAY OF MAKING SURE GRAY STAYS NEUTRAL, NEITHER WARM NOR COOL IN (IDEALLY) WHATEVER LIGHTING SITUATION YOU'RE IN.

- As far as wanting "tungsten to LOOK tungsten", I'm not sure exactly what to say. I'd recommend white balancing the shot, and then if while editing you'd like to color to be a little warmer or cooler, adjust the colors in the editing software.
 
Than what is the point of using lights with a certain temperature. Why arent the came lights used for everything and then white balance will manipulate the color spectrum to make it look natural?


sorry if im frustrating you lol
 
Because unlike your eyes, cameras can only make a certain kelvin (K) temperature look white at a time.

If you told your camera that 3200K is white (tungsten light) and you had daylight in your shot (5600K), the daylight would look very blue and skin tones, white point, and everything would look wrong.

The easiest way for you to understand this though is to take your camera and just go try white balancing under different light sources and see the effects. Very soon you will realize that for lack of a better term, things just look "wrong" with an incorrect white balance.
 
First I suggest you read this:

http://www.cambridgeincolour.com/tutorials/white-balance.htm

I know you probably have some background on the subject but I just want to make sure we are on the same page here.

Generally when I shoot I try to white balance to one of two settings, 5600K or 3200K (I can dial it in on my XH A1). The reason I do this is because when you work with film you have one of two options for white balance: Daylight (5600K) or Tungsten (3200K).

FUN FACT: If you look at the names Kodak film stocks you can tell whether they are daylight or tungsten based on the letter (T or D) right after the film speed. For example Vision 2 200T 5217 is tungsten and Vision 2 500D 5205 is daylight. Also the 5 in the film "name" represents 35mm film as opposed to the 7 which represents 16mm film (for example Vision 2 500D 7205 is the 16mm equivalent of the 5205)

Once I've picked one of the two color temperatures I try to manage all my colors around it. For example if I'm shooting at night indoors I'll use 3200K. The lights indoors will appear white. However If I want a blue light to represent the moon I'll put some gels (CTB - Color Temperature Blue) on it in order to raise the temperature up closer to 5600K, which will appear blue. This choice is purely aesthetic and it is one of the benefits of using different light temperatures. If I want the lights to look more orange I'll add a gel (A CTO - Color Temperature Orange) in order to lower their temperature and make them look more orange.

Realize the white balance isn't a magic wand that fixes the colors. It just creates a setting for the mixture of colors in the room. THERE IS ABSOLUTELY NO WAY to create a perfect white balance in a mixed lighting situation. If you are in a room with daylight and tungsten lights it will not work. That is one of the reasons I really dislike the electronic white balance settings on most cameras.

If I was setting white balance electronically in the camera, I would just get white and I wouldn't have a clue what the white balance was set to so it would be really hard for me to change light colors to match my artistic needs. That's why I choose to use the set temperature method that is used in film. Now this is for purely narrative filmmaking that allows me to control the light temperature for my needs, in a documentary setting I would certainly white balance every shot.

As you can see this is one of the big reasons professional lighting equipment is expensive. Those lights are reliably designed so always maintain the same color temperature and to behave exactly as a cinematographer needs them to behave.

We add color by using gels and carefully playing them off the white balance settings. These colors have to be well picked. If your white balance is set to red and you use a red filter, you are just getting white anyway.

The concept of white balance and color temperature manipulation is rather complicated but there is a lot of good literature on the subject. I highly suggest you get a copy of Harry C. Box's book The Set Lighting Technician's Handbook. I never go anywhere without it. I also suggest you look online for information about MIRED units. It's a bit advanced and probably not really necessary for most prosumer filmmakers but understanding them will give you an edge when trying to make artistic decisions regarding color.

Hope that helps somewhat.
 
great info Ozar...definately answered a question i was just about to ask...(why is lighting so darn expensive?) ....reliability..<--------- totally understandable now. (though i still think there are a couple companies who are overscharging for marginal reliability.)
 
I am extremely interested in the advanced technical aspect behind concepts and am now researching this in depth.
 
Qzar - you say:

THERE IS ABSOLUTELY NO WAY to create a perfect white balance in a mixed lighting situation. If you are in a room with daylight and tungsten lights it will not work.

then:

in a documentary setting I would certainly white balance every shot.

Surely some mistake?

IMHO - presets are preferred in the majority of situations
 
pwyll said:
Qzar - you say:

THERE IS ABSOLUTELY NO WAY to create a perfect white balance in a mixed lighting situation. If you are in a room with daylight and tungsten lights it will not work.

then:

in a documentary setting I would certainly white balance every shot.

Surely some mistake?

IMHO - presets are preferred in the majority of situations
Click to expand...

For a 'documentary', or say, a 'wedding', the light color cast may change from room to room, or during the day, for example varying clouds, give 'bluish', to 'yellowish', depending on the sun, and holes... etc.

So, I'd say 'white balance' for every shot is good advice for a documentary.

However, if one has a fixed setup, fixed lights, etc. given that 'white balance' is an interative process in the camera, it may actually give a 'different' balance across successive 'balances'. Perhaps in high end fancy cameras the algorithm will converge to the same balance... but I'm not convinced about prosumer...

The same order of things with auto focus, or anti-vibration, where the algorithm may move things around, despite everything in the scene being fixed.

In the case of mixed light, sun light, tungsten, either filter one or the other, or compromise...
 
Yes I understand many people insist on electronically white balancing every scene. Most older textbooks recommend this practice without even mentioning the "mixed lighting" gotcha. Think about it - most indoor run-and-gun shooting is mixed light.

I suspect the problems you are having getting consistent WB readings are operator error rather than faulty electronics. In mixed lighting minor changes in the position or angle of white card and camera can yield wildly different readings.
 
pwyll said:
Yes I understand many people insist on electronically white balancing every scene. Most older textbooks recommend this practice without even mentioning the "mixed lighting" gotcha. Think about it - most indoor run-and-gun shooting is mixed light.

I suspect the problems you are having getting consistent WB readings are operator error rather than faulty electronics. In mixed lighting minor changes in the position or angle of white card and camera can yield wildly different readings.
Click to expand...

Yeah in a run and gun situation you really should white balance electronically whenever the lighting changes dramatically. What I'm trying to say basically is that it's impossible to get good "white" results in a mixed lighting situation. If you are in a room with tungsten lights and big windows, the white balance no matter how hard you try is always going to be biased towards one of the color spectrums. The difference is just too great.

It's important to be aware of the lighting conditions even when you are white balancing electronically. If you can bring the general lighting close to one of the spectrums it will make your life easier in the long run and give you better results.

These are the kind of questions people NEED to ask, it took me a lot of searching to find answers to them in the past. I'm glad forums like this exist.
 
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