Blink free and picture perfect

As the New Year kicks off, and the country awakes from its festive slumber, many a thought will turn to planning the summer holiday to break the winter blues.

"Can everyone just stop blinking! Otherwise I'll have to work out this equation."

Whatever the choice of get-away, you’ll need to make sure that you get the perfect holiday snap - a feat that is not as easy as it sounds, especially if you want to catch everyone with their eyes open.

But fear not - to help photographers get the perfect shot, an Australian scientist has calculated the number of photos that need to be taken to ensure at least one blink-free photo.

“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 Organisation. “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.”

To get the right calculation, Barnes's equation takes into account the average number of times a person blinks (10 per minute), how long a blink lasts (250 milliseconds), camera shutter speed (8 milliseconds in a typical setting), and the number of people in the group.

“For groups of less than 20 people, divide the number of people in the group by 3 if the light is good or by 2 if the light is bad,” Barnes said. “Take that number of shots and you will have a better than 95% chance of getting at least one good one."