Learn more about the Guided 365 here!

“How to Use a Gray Card to Set Custom White Balance” is an excerpt from the Digital Photography for Moms Guided 365 project. The prior lesson explained how to use a piece of white paper for setting custom white balance in a pinch. This lesson provides you with a downloadable DIY gray card for more accurate custom white balance.


My gray card is a grubby old piece of cardboard that I tore from the back of a Scott Kelby book 7 years ago. I should probably update it – the gray is rubbing off in spots and I’m sure it’s getting dirty.

When I upgrade, I’ll get something like this that’s more durable:

gray card

To set custom white balance, begin by taking a photo of your gray card. Make sure it’s in exactly the same light as your subject, facing the camera. Zoom in, or get close enough to the card that it fills your entire viewfinder. Below is the photo I took:

gray card

That photo doesn’t even begin to look gray, does it? It’s very warm. This warmth means that the lighting is causing the camera to see gray as this beige color.

Shooting a gray card can be tough, by the way, because the camera doesn’t have anything to focus on. If you experience an inability to focus,  turn off AutoFocus momentarily. (Most lenses have a switch to toggle between auto & manual focus.) The photo you take for your custom white balance doesn’t need to be well focused, just well exposed.

Now that you’ve taken your photo, set custom white balance on your camera by following these steps:

Navigate to the Custom White Balance menu item on your camera. It will prompt you to navigate to the photo you’ve taken of your neutral area. (This menu item will be in a different place and might even have a different name from camera to camera. If you can’t find it, check in your manual.)


Next, my camera reminds me to change my White Balance setting to Custom. This is something that I tend to forget – it seems to me that the camera should change it automatically. Why go to the bother of setting a custom White Balance if you don’t want the camera to automatically use it, right?


Anyway, learn from my mistakes and go change your White Balance preset to Custom:


Now your white balance is set and you can take your photos. You would need to repeat this process if you move your subject or if the light changes.

Here is the photo I took with this custom white balance setting:

tech 2

And here is a comparison to a photo with auto white balance:

tech 1

Big difference, right?

Now, what if you don’t have a gray card? Get creative! Find a neutral gray in your house that you can set white balance from. Or download this photo. (Just right click on it and select Save Image As.)

How to Use a Gray Card to Set Custom White Balance

Print the file (it’s sized to be 4×6) and use it as a gray card. Now, the quality of the gray is only as good as your printer. Might be a good idea to print it in black & white to make sure that you get no color with it. Also, print it on the most purely white paper you can find.

Did you like this lesson about how to use a gray card to set custom white balance? Check out the Guided365 if you’d like 364 other step-by-step tutorials! Our workshop begins January 1 – don’t miss out!

Today’s Assignment

  • What to Shoot: Something white.
  • How to Shoot: On manual mode using a gray card for setting Custom White Balance. Shoot in Auto WB also, to compare the results.
  • Hashtag: #Guided365, #Day90Guided365
  • Include with Post: Your settings. Which photo was more accurate – Auto or Custom White Balance?
  • Carry forward from this assignment: Gray cards are an inexpensive way to set proper white balance.