White Balance

Among the things I learned in Digital Imaging: Reset, the most important lesson was *everything*. It turns out I’ve been using my digital cameras wrong this whole time. All the way back to my very first 3MP Canon in 2001, a hand-me-down from my father, which is now completely outclassed by my cell phone.

I kept my camera on Manual mode because I knew how to work the F-stop, Exposure time, and ISO to my advantage. And what else did I need to know, really? I even set it to custom white balance sometimes, because I was so clever. And I thought, the trick to white balance is to tell it what the whitest white in the scene is, so nothing goes beyond that and gets blown out.

There are two little problems with that theory…
1: That is not what white balance is for. It wants to know the MIDDLE tone and sets whites and blacks accordingly.
Because it is a digital camera, that means the middle of values between 0 (black) and 255 (white). The exact middle is 127, grey. For an RGB colorspace, that would be 127/127/127, a warm grey.

How would you know when you’ve got the exact right grey? Well, that’s what those funny little grey cards are for! You know, the ones that sometimes come with the camera. Yep, there is a reason for that.

2: Setting custom white balance requires entering a special white balance metering mode, which looks at the dead center of the selected shot. So you put your grey card wherever you plan to focus, at the exact settings you plan to use (no zooming in later, no suddenly changing the f-stop, no nothing) and cover as much of the viewscreen as you can with the grey. Which means you cannot use it for long-distance compositions! It is, however, great for portraits and close-ups.

The assignment was to set the custom white balance using the grey cards, and compare it to the white balance presets on the camera.

Example 1:
Wood paneling, indoor light

Custom white balance is a clear winner here.

Example 2:
Popcorn, filtered daylight

I like the look of auto white-balance best, because popcorn looks best very pale. But the truth is, this popcorn is slightly yellowish, and custom white balance is somewhat more accurate. I think the truth is somewhere between the two. I experimented with the other white balance settings for comparison, those were much farther off (unsurprisingly).

So, from now on my close-up composed shots are going to look much nicer! The action and distance shots will not change appreciably – but who knows what the rest of the course will bring.


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