If you’ve ever taken a photo of a group of people, you’re probably used to the chant of ‘oh no, I blinked’, usually from that obnoxious little blonde that you can’t stand the sight of. But did you know that there is actually some science behind taking photos of people, and whether they blink or not?

Behold – the guide to avoiding people’s half-closed, semi-drugged looks!

People who always blink

As a photographer, you eventually come across people who always seem to blink in photos. They probably aren’t aware they are doing it, but they are – and rather consistently, too. This isn’t a coincidence, it’s actually an effect of the way modern flashguns work. New, high-tech flashguns use a pre-flash to measure the light available, and then shoot the ‘proper’ flash a fraction of a second later. This happens so quickly that you don’t even notice it – it looks like a single flash. Some people — especially some athletes and top gamers — have very fast reactions, however, and will blink as a reaction to the first flash, so by the time the photo is actually taken, you are photographing their half-closed eyes.

So how do you avoid it? Well, there’s nobody who can react fast enough to close their eyes on a single flash (it’d mean you would literally have light-speed reactions, and that’s physically impossible), so all you need to do is to avoid the first flash. There’s no button on a flashgun or a camera anywhere that says ‘turn off pre-flash’, but there are settings you can change that does this.

Knowing that the flashgun uses the pre-flash for measuring light gives a hint: Just prevent it from doing light measurements! You can do this by using the flashgun in manual mode: Set the flash output yourself. To find out how much flash you need, either learn how to use your flash (there’s a rather excellent article about this on the Digital Camera website), or just use the trial-and-error method.

Alternatively, you can use the Exposure Lock function (circled in red on the D400 400D on the left here) that exists on most advanced cameras. By pressing the button, you are forcing the camera to do the light metering it needs to do. When you are ready to take the photo, it won’t bother doing any measuring, which means that there is no pre-flash, and your photo-victims won’t be blinking!

Avoiding blinking in groups

I found a wicked little article on LiveScience.com titled Picture Perfect: How to Make Blink-Free Holiday Photos, which goes into the science of taking blink-free photos of people. It’s actually quite a funny read (if you’re a geek, like me)

“At any given moment for a typical person, their eyes are likely to be blinking about 4 to 5 percent of the time,” said physicist Piers Barnes of the Commonwealth Scientific and Industrial Research Organization. “This is fine if you only want to take a photo of one person, but once you start adding extra people, then your chances of getting an unspoiled photo start dropping.”

Excellent, yeah? Thought so. Now go read the article :)

(The livescience article is via this comment)

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