What Is White Balance?

Why Cameras Need White Balance At All

Human vision performs color constancy automatically: a white shirt looks white to you whether you're standing under a candle, an overcast sky, or a fluorescent office light, because your brain continuously discounts the color of the ambient light. A camera sensor does not do this. It records whatever wavelength mix actually reaches it, so the same white shirt comes out orange under candlelight, blue in open shade, and greenish under some fluorescent tubes unless something corrects for the light's color first. White balance is that correction: an instruction telling the camera (or your RAW editor) what color the ambient light is, so it can shift the recorded colors back to neutral.

The Kelvin Scale

Light color is measured in kelvin (K), a scale borrowed from the color a theoretical heated object glows as it gets hotter. Low kelvin values describe warm, orange-red light: candlelight sits around 1900K, household tungsten bulbs around 2700-3200K. Middle values describe roughly neutral daylight, around 5000-5600K at noon. High kelvin values describe cool, blue light: open shade often runs 7000-8000K, an overcast sky can push past 9000K. The scale runs opposite to everyday color language: "warm" light is low kelvin, "cool" light is high kelvin, even though we call the numbers themselves "high" and "low," not warm and cool.

The Part That Confuses Everyone: Which Way the Camera Dial Goes

Here is the detail that trips up most people learning manual white balance: setting a higher kelvin value on your camera's white balance dial makes the photo render warmer, more orange, not cooler. This feels backward until you remember what the dial actually means. It is not telling the camera what color you want the output to be; it is telling the camera what color it should assume the ambient light already is, so the camera can subtract that color back out. If you dial in a high kelvin number, you are telling the camera "assume this light is very blue," and the camera responds by pushing heavy orange correction into the image to neutralize the blue it now believes is there. Dial in a low kelvin number and you're telling it "assume this light is very orange," so it pushes blue correction in instead, and the result looks cooler. The light in the room has not changed; only what you told the camera to assume about it has.

White Balance Presets

Every camera ships with presets that pick a fixed kelvin value (roughly) for common lighting: Daylight (around 5500K), Cloudy (around 6500K, adding warmth to compensate for overcast blue), Shade (around 7500K, adding more warmth still), Tungsten (around 3200K, adding strong blue to cancel orange bulbs), and Fluorescent (variable, since fluorescent tubes vary widely and often need a slight magenta shift too, on top of a kelvin shift, to correct their green cast). Auto White Balance analyzes the scene and guesses; it is good enough for casual shooting and unreliable the moment a scene has strong color casts, mixed light sources, or a dominant color subject that fools the algorithm into "correcting" a color that was never a lighting problem in the first place.

Custom White Balance With a Grey Card

For accurate, repeatable results in a fixed lighting setup, photograph a neutral grey or white card that fills the frame under the actual light you'll be shooting in, then use the camera's custom white balance function to sample that shot. The camera measures exactly what color the "neutral" reference came out as and builds a correction from that measurement instead of a guess. This is standard practice in studio, product, and any color-critical work, because it accounts for the specific mix of light in that specific room, which a generic preset cannot.

RAW vs. JPEG

This is where the file format you shoot in matters more than almost anywhere else in photography. A RAW file stores white balance as a metadata instruction layered on top of unprocessed sensor data; changing it later in software is non-destructive and identical in quality to having set it correctly in camera, because the underlying data never had a white balance baked into it. A JPEG applies the white balance setting permanently to the pixel data at the moment of capture. You can still nudge a JPEG's color temperature afterward, but you're pushing already-processed, already-compressed pixel values around, with real quality loss the further you push. If you shoot JPEG, getting white balance right in camera matters. If you shoot RAW, white balance is a creative decision you can defer entirely to your editor without any penalty.

Mixed Light

A single white balance setting can only correct for one color of light at a time. A room lit by a tungsten lamp near a window letting in daylight has two different color temperatures in the same frame, roughly 3000K near the lamp and 5500K near the window, and no single kelvin setting neutralizes both; correcting for the tungsten leaves the window light looking unnaturally blue, and correcting for daylight leaves the lamp looking deep orange. Professional solutions include gelling the lights to match one temperature (an orange "CTO" gel on a flash to match tungsten ambient, or a blue "CTB" gel to match daylight), turning off or blocking one source, or simply accepting the mixed cast as part of the scene's character, which is often the better choice for documentary or available-light work where fighting the light isn't worth the effort.

Creative White Balance

Nothing requires white balance to be "accurate." Deliberately setting a cooler-than-correct white balance during a sunset intensifies the orange rather than neutralizing it. Setting Tungsten white balance in broad daylight (telling the camera to assume very warm ambient light when it's actually neutral) pushes a strong blue cast across the whole scene, a common deliberate look for night, cold, or unsettling moods. Because RAW files keep white balance as an adjustable instruction rather than a baked-in change, the safest way to experiment creatively is to shoot RAW at a neutral or slightly-off setting and push the color further in post, where you can compare options side by side instead of committing in the field.

See It Side by Side

Which photo has a warmer color cast?

A B

Common Mistakes

• Assuming Auto White Balance is "correct" by default. It is a guess, and a busy or heavily mixed scene will fool it more often than a simple one.
• Mixing up which direction the kelvin dial goes. A higher number on the white balance dial makes the image warmer, not cooler, for the reasons explained above.
• Fighting mixed light to a "perfect" neutral instead of picking which source to serve. Usually one color cast has to win; deciding which one on purpose beats a muddy compromise.
• Nudging white balance repeatedly on a JPEG and wondering why color starts banding or shifting oddly. That's cumulative quality loss from adjusting already-baked pixel data; shoot RAW if color accuracy matters.
• Treating white balance as a fixed camera setting rather than a creative tool. "Wrong" white balance, applied on purpose, is a legitimate way to set mood.

Try This

Photograph the same static subject under one light source (indoor lamp, window light, or open shade all work) using each white balance preset your camera offers: Auto, Daylight, Cloudy, Shade, Tungsten, and Fluorescent. Line the results up side by side. You'll see the same scene rendered from strongly orange to strongly blue from nothing but a menu setting, which is the fastest way to build an instinct for what each preset is actually assuming about the light.

Related

• Color Temperature: the glossary entry behind the kelvin numbers on this page.
• Kelvin: the unit itself and its origin.
• RAW: why RAW makes white balance a non-destructive decision.
• Golden Hour: the natural low-kelvin light most photographers first learn to recognize.
• Fundamentals Lesson 3: Understanding and Choosing Lenses, with the in-browser camera simulator.

Test Your Knowledge

• White Balance & Color Temperature Quiz