Sunday, March 28, 2010

The Case of the Tinted Picture

You're inside. Following the advice of the previous post, you turn on a lot of lights. The lighting *seems* fine, but you take a picture and this happens:

Tinted Shot

What went wrong?


Remember what I said earlier about cameras 'seeing' light in absolutes? It just happened again.

Fortunately, most cameras have what's called White Balance. Unless you change it, it's also set to 'Auto' - which does a fine job in certain situations - but not the one above obviously.

So how do I fix it?

If you have Photoshop, you can correct the problem somewhat using 'Curves>Auto' but it's really only half way there.

Curves Photoshop

A better option would be to fix the problem within the camera.

Bad News: You can't do anything about the shots you've already taken*.
*Unless you shot in RAW Mode
Good News: It's a better fix than Photoshop.

How?

Take a picture of something that's supposed to be white. That something should also be very close to what you're going to take a picture of. Technically it should be 18% gray, but white is easier to find and it doesn't make a huge amount of difference. You might find it helpful to put the camera in manual focus mode so it doesn't have to try and lock onto anything - it will just take the picture.

Custom White Balance

Find how to how to set 'Custom White Balance' with your particular camera. Use the picture like the one taken above for calibration.

Take another picture with an actual subject in it. It should now look like this:

Custom White Balance Fixed

2 comments:

Shadowsdream said...

You can also pick up white balance cards or kits which will help out with this process. I've even found them as magazine inserts in photography and photoshop magazines. The WhiBal kit is highly rated if you wanted to spend some money on a card which will work in nearly any conditions, their pocket kit is available for $29.95 form various online resellers, but they have studio kits as well that I found.

James said...

From what I've read - and a certain amount of practical experience - a plain white sheet of paper is fine for White Balance.

The 18% grey cards are more for exposure settings - but they can do double duty.

You can split hairs over how grey (or white) something is, but a CWB is going to get you a lot closer, a lot faster than most other methods.

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