2.5 – Lighting – White Balance

Okay, we’re not going to get TOO crazy on this one.  I want you to walk away with a basic understanding and to have a few links, should you choose to dig in deeper.  Have you ever heard someone say they need to adjust the color temperature or white balance?  You just kind of act like you know what they’re talking about.  There are some phrases in photography that are mentioned a lot and yet seem to evade us in meaning.  How can color have a temperature?  That doesn’t even seem to make sense. Color temperature is measured by a scale called Kelvin (K) and it refers to the intensity of visible light along the scale.  This part is going to jack with your head, so bear with me…

The lower the “K” number, the warmer a light source is considered.  The higher the “K” number, the cooler a light source is considered.

When you’re in your living room at night and you have an incandescent lamp on, have you noticed how the room looks kind of orange?  Well, that’s considered “warmer” Kelvin (maybe 2700K).  And when you’re outside in the middle of the day, the light is very blue-ish white?  That light is “cooler” Kelvin (5500K).  It’s a bit counter-intuitive, because when we’re heating up your oven, the higher the temperature, the higher the number.  But, it’s the opposite here.  The cooler the color, the higher the number (temperature).  The warmer the color, the lower the number (temperature), in Kelvin (K).  Here’s a scale so you can see what I’m talking about.

Color Temp Chart - FreestylePhoto.biz

See what I’m saying?  The lower that number, it gets warmer and warmer looking…like a flame.  And that blue gets bluer and bluer until it becomes black.  Alright, all of that scientific hobble-dee-gobble to get to the point…White Balance.  Now, we’re talking about photography again, thank the Lord.  Remember how I’ve talked about our eye as a type of camera?  It lets in light and adjusts to the levels of light on-the-fly.  Well, another way that our eye and brain adapt to available light is by changing the way we interpret the color temperature of a scene.  Our eye looks at something that is “white” and says, “Hey pal, that t-shirt is supposed to be white.”  So, even if the color temperature of a room is very orange, and the t-shirt is looking orange, our brain, via our eye, will work very hard to interpret that shirt as white, but it has it’s limitations and that’s why everything ends up looking kind of orange.  Look at the scale above and you can see how the color gets darker and darker the further away from “white” (5500K) that it gets. Both directions, bluer AND redder.  So, our brain is working harder to change it’s interpretation of “white” back to “white”.  Right around 5500K, our brain doesn’t have to work too hard to adjust the “white balance” to see “white” as “white”, anymore.  It’s just straight up “white”.  So, we see all colors pretty accurately, and without a color-cast.

When we adjust the “white balance” of an image, we are changing the “K” to a level that allows “white” to be “white”.  It’s all relative.  So, no matter what the actual temperature of “K” in a room, we can input a “K” number into our camera (or in post-processing) and trick the camera into making “white” look like “white”.  That’s why it called “white balance”.  We are balancing the actual color temperature and bringing it in line with an altered color temperature that will allow us to see white as white.  Here are some examples…

Accurate Color Temp of 5,850K that matches actual shooting conditions

As you can see here, the image is fairly white and it’s pretty much balanced.  I shot this on a sunny day.  It is close to that sweet spot I was telling you about where your brain doesn’t have to work too hard to make “white” look “white”.  So, what will happen if I grab the Temp slider (as seen here in Adobe Lightroom)…

….and slide it left towards, let’s say 3200K, therefore making the color “warmer”?  It should be “warmer”, or more orange-ish, right?  Wrong.

Color Temp changed to 3,200K from actual 5,850K Color Temp

“Kevin, I’m so confused I want to hit myself in the head with a tack-hammer”.  That’s what Tommy Boy would say.  If I changed the color temperature in the computer to a “warmer” temperature, why is it looking cooler and cooler?  The answer is simple.  You are telling the computer that what it is looking at is really 3200K, when in reality, it was about 6000K.  So, it’s like you’re telling the computer, “Hey, I know this looks like it was out in the middle of the day, but she was really sitting by the fire sipping hot cocoa with a couple small lamps.”  So the computer goes, “Ohh, okay.  My bad.  I will now adjust everything in the picture to that new reality.”  What was actually pretty realistically white, is now much much bluer.  Let’s look at the opposite….

Color Temp changed to 10,000K from actual 5,850K Color Temp

We’ve now gone the opposite direction and told the computer that the real color temperature is supposed to be 10,000K.  In other words, we were saying, “Computer, the lighting conditions were really, really blue that day and the color temperature should have actually been 10,000K. ” So, the computer says, “Ahh, okay.  I will change the color temperature to 10,000K.”  Now, everything in the picture will be much warmer, relative to that new reality.”

That’s why everything looks so warm.  It’s simulating what it would look like if lighting conditions were normalized, relative to that temperature.  But, it’s really not normalized, is it?  It’s too orange (warm).  Because we did not feed in accurate directions as to what the REAL white balance should have been.

I hope at this point that you are not cursing me too much.  I’m sure some brains have imploded.  Mine has, just trying to teach this.  The good news is that your camera and computer are really, really good at understanding “white balance” in Auto mode.  Most people shoot in Auto White Balance mode and are just fine with the results.  A lot of times that’s what I leave it in, because I know that I will always adjust it later in Lightroom.  Now’s the time to make a really important point…

Always shoot in RAW mode (if you have it). When you shoot in .JPG, you have very limited control over color temperature, later in post-processing.  When your camera is shooting the picture, it locks in the color temperature, and then encodes the file.

This is the number one reason why you don’t want to shoot in .JPG… a lack of ability to accurately change the color temperature later in post-processing.  If you decide to ignore my advice, you’ll need one of these…

This is a “grey card”.  You may have seen people using these.  It’s 18% grey, and it helps your camera to know what the real white balance is.  You basically take a picture of the grey card right at the beginning of your shoot, and then tell your camera, in the menu, to key off of that grey card as the proper “K” level or “White Balance”.  I don’t want to take the time to explain why you don’t just use a white card, instead, just trust me.  Grey gives your camera’s sensor a better understand of what is “white” better than white does.

If you shoot in Auto White Balance in RAW, you will never have to jack with grey cards.

The last tip I’ll give you is this…people’s skin generally looks better when the perceived color temperature is “warmer’.  In other words, when we look like our skin is more tanned.  If you fudge, fudge in the direction of making them look more orange than blue.  Blue makes people look like cadavers.  I’ve never had a client ask me to make them look like a cadaver.  So, to that end, I generally shoot in “Cloudy” mode on my White Balance modes, when I’m shooting people.  It doesn’t lock anything in.  It just allows me to quickly see what it would look like later on if the person was more warm.  This mode looks really good with women, in particular.

It’s a bit of a feel thing.  You just have to look at something and see what looks good to your eye. Grab that slider (every photo editing program has a Temp slider) and pull it back and forth, until you find something that looks nice.  I know that this is a bit confusing, but hopefully now you have a better understanding of White Balance.  Here are a couple great links if you want to dig further into the subject…

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

http://www.photoxels.com/tutorial_white-balance.html

My hope is that this was fairly helpful, that there weren’t too many mistakes, and that the real experts would come in and scorch me in the comments section, so I can edit this post and actually make it accurate.  🙂 Feel free to ask me any questions you may have and I would love to see your images in our Flickr group.  Now, go sit in a padded room and give your brain a chance to rest.

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