I’ve often heard people say “the camera adds ten pounds” when they’re photographed. Is that just an excuse or is there any truth to it? —Emma

No question there’s an element of denial here. Since you’re not looking at yourself most of the time, it’s easy to maintain a self-image reflecting the svelte physique you had 10 years ago. But that’s not the whole story. For reasons having to do with optics and the way your brain works, the camera can in fact make you look heavier than you are.

The main difference between a camera’s view of the world and yours is that the camera has a single “eye” whereas you have two. That subtly changes the way things look. Here’s an experiment. Pose a round object in front of a varied background—a coffee cup in front of the computer monitor worked well enough for me. From a distance of two or three feet, look at the object alternately with both eyes, then one. You’ll notice that, seen with one eye, the object looms larger in your field of vision, and obscures more of what’s behind it. It seems bigger and bulgier. In other words, it looks fat.

To find out why, look at the object first with your right eye, then your left. Notice the familiar shift in perspective known as parallax—background features hidden from one eye can be seen by the other. When you look at the object with both eyes, the brain blends the two views together. You see more of what’s behind the object, making it seem smaller. Result: Binocular vision is slimming, monocular the opposite.

There are ways to compensate for the fattening effect of the camera. One is to use a telephoto lens when shooting portraits. Step back from the subject and zoom in—parallax, and thus the addition of pounds, diminishes with distance.

If you don’t have a telephoto lens but you do have digital photo-editing software, you can still step back when taking portraits and crop out the extra background later. If you’re on the other side of the camera, here’s some advice: Watch out for amateur photographers who feel they need to have the subject fill the frame. They’ll tend to take portraits from three feet away, making it appear that your face has been painted on a balloon.

There are other ways to make people look slimmer:

• “Short lighting” can make a broad face look thinner. The subject turns one side of his or her face toward the camera and the photographer shines a studio light on the other. Bright lighting on half the face tends to elongate it.

• Dress your subject in black and put him against a dark background.

• Have the subject turn at an angle to the camera, creating a narrower silhouette.

• Let’s not forget those vertical stripes.

• Get Mister Chubs to lay off the

chimichangas. —Cecil

How much nutrition do you get from eating corn? I know the day after I eat corn, what appear to be full kernels are released back into the wild. Does everyone have this condition? —Just Being Corny, Reno

It’s not just you, my friend. A corn kernel has a tough outer hull that’s about 90 percent crude fiber and none too digestible. However, the human body’s capabilities include an amazing process that enables us to get the most out of stubborn foods. It’s called chewing. Thus exposed, the inside of the kernel is loaded with nutritionally useful stuff—starch, sugar, protein, and oil.

Even if you don’t chew it enough, corn probably still does you some good. My assistant Una calculates that, at most, 10 percent of corn’s bulk is truly indigestible. We’re assuming that your digestive juices manage to breach the hull. To be on the safe side, though, listen to Unca Cecil: Sit up straight, get lots of fresh air, and chew your food. —Cecil Adams

Is there something you need to get straight? Take it up with Cecil at straightdope.com.