By Dave Johnson
May 26, 2010

SAN FRANCISCO – Have a question about digital photography? Send it to me. I reply to as many as I can–though given the quantity of e-mails that I get, I can’t promise a personal reply to each one. I round up the most interesting questions about once a month here in Digital Focus. For more frequently asked questions, read my newsletters from February, March, and April.

Better Exposures for Dark Complexions

I frequently volunteer in Haiti, where the Caribbean sun is usually very bright and the people are very dark skinned. I use a compact camera and, in nearly every shot, the camera compensates for the bright surroundings, so facial features are lost in shadow. What adjustments can I make to try to solve this problem?
–Brandon Johnson, San Francisco

You’ve got a tricky exposure situation, Brandon. In very bright sunlight, your scene probably has a broader range of exposures (from sunny background to dark skin) than it’s physically possible for your camera’s sensor to record.

If your camera lets you attach filters in front of the lens, you might want to invest in a neutral density filter, which will reduce the overall exposure by a stop or two. Or you can use the camera’s flash as a “fill flash” to put more light in your subject’s faces. If you find that it washes out the subject too much, see if your camera lets you reduce the intensity of the flash–set it at 50 percent power, for example, for more subtle results. Or finally, try the camera’s exposure compensation setting (usually marked EV) to overexpose the scene a bit. That might “blow out” the background, but will improve the exposure of your subject’s faces.

Owning Photos From the TV

Recently I took some shots of a travel program on the TV. Are those my shots? Can I use them any way I wish? What are the legal ramifications?
–Al McConnaha, Huntsville, Alabama

First, my standard disclaimer when issues of copyright arise: I am not a lawyer, so don’t take anything I write as legal advice. That said, when you take a photo of something on TV, you’ve made a copy of someone else’s intellectual property. It’s no different than making a copy of a photo, painting, song, or movie. You don’t have any legal right to use these photos in any way except for personal use.

There is an exception, though. Artists can generally incorporate other people’s work into their own–this is the root of concepts like “sampling,” “remixing,” and “mash-ups.” Oh, and another point: Any media created by the U.S. government is automatically in the public domain, so I suppose you’re free to reuse anything you photograph on C-Span.

Long-Term Photo Storage

I have a lot of pictures saved in my hard drive and make back-ups on DVD and flash drives. But what is the best way to archive my pictures long term?
–Efrain R. Camara, Myrtle Beach, South Carolina

The best long-term storage that money can buy is a second hard drive. You can get a terabyte of storage for under a hundred dollars, which is a mind-bogglingly good value. So buy an external terabyte drive, plug it into your computer’s USB port, and use it to make regular, automatic backups of your photos and other data. The drive will last for years. When it eventually fails, replace it with an even bigger, even cheaper drive.

I don’t suggest messing with DVD backups. No one really knows how long they’ll last–25 years? 50 years? And you won’t really know they’ve failed until you try to use one and discover it’s dead. But archiving your valuable stuff on a backup hard drive is easy, economical, and you’ll know instantly when it has failed. As long as you also maintain a copy of your stuff on your computer’s main drive, you’ll always have two copies and you’ll be safe.

The truly paranoid among us make occasional backups to a third hard drive and store that one off-site for safekeeping, such as in a safe deposit box.

Card or Cable?

I enjoyed your column about the care and feeding of memory cards. Do you have any thoughts on whether the best way to transfer photos to the PC is to use the cable that came with the camera, or whether it’s better to use the memory card for the transfer? I’m inclined to use the cable since it minimizes the handling of the card. –Bill Lavezzi, Victoria, Texas

Unless you’re using ancient Smart Media cards (those long-obsolete wafer-shaped memory cards used by early digital cameras), I don’t think you have anything to worry about from handling memory cards–even kind of roughly. Memory cards have been known to survive falls out of five-story buildings, trips through the washing machine, and even being lost at sea.

I strongly recommend using a memory card in a card reader, since it means you don’t have to drain the camera’s precious battery life just to copy files from the camera to the PC. And if you have concerns about damaging hardware, I’d be a bit more worried about the sometimes-delicate cable connector on your camera.

Eye Damage from Flash?

I enjoyed your article on “Five Tips for Better Flash Photography” and it offered really great advice. One question that I’ve always wondered about: If you are taking pictures of your pets or babies, approximately how far away should you be when using the flash to avoid subject eye damage? –Marcia Richardson, Manchester, New Hampshire
Here’s another standard disclaimer: I am not a doctor, so don’t take anything I write as medical advice. Now that I’ve gotten that out of the way, let’s proceed.

While I wouldn’t cite this as one of the Great Myths of Photography, it certainly ranks up there with the most persistent misinformation that simply won’t go away. I’ve heard people worry about this for years, but the reality is that you can’t damage anyone’s eyes–adult, baby, animal–with a camera flash, no matter what distance. It takes a sustained, long duration beam of high intensity light to damage eyes, Marcia, and camera flashes are too brief and diffused to come even close to doing any damage. Indeed, doctors will tell you that they routinely use camera-like flash devices to diagnose eye issues and that flashes pose no danger.

We don’t usually often think of it this way, but photography is really about drawing pictures with light–which means that you can literally draw your own pictures by adding light to a photo in a controlled way. Many years ago, before digital photography, I used to experiment with this sort of photo using long exposures and a flashlight. In the past, I’ve shown you how to mimic that effect digitally (“Add Sci-Fi Special Effects“). This week, I thought it would be fun to do it the old-fashioned way and actually “paint” with a flashlight.

Get Set Up

Painting with light is more art than science: You can get great results with almost any kind of camera, and experimentation is key. Unlike the kind of experimentation I remember from my college physics class, though, this is actually fun.

To get started, you’ll want a digital camera that has some sort of long exposure mode. Ideally, you’ll be able to set the shutter speed to 8 or 16 seconds. I’ve found that 8 seconds is barely time to do anything, so honestly, you’ll get more satisfying results if your camera has a 16- or even 30-second exposure setting.

You’ll also need to set the camera on a stable surface. Since you can’t really hold it still for 16 seconds, a tripod is ideal. You could also just set it on a desk, table, chair, or any other surface that isn’t going to move around during the exposure.

And finally, you’ll need some light sources. You should gather one or more flashlights, and, if possible, an external flash unit. Don’t mount the flash on the camera–you’ll want to hold it and trigger it manually.

Taking the Shot

Now that you have your supplies ready, wait for nightfall and position your camera for a photo. Your surroundings should be as dark as possible, such as in a room with the lights turned off. or outdoors, away from street lights. Press the shutter release to start your long exposure, and then use a flashlight to “inject” light directly into the scene.

One way to use your flashlight is to mimic a sci-fi “phaser” effect, like this old photo from my film days. I achieved this shot of my buddy Paul “phasering” Bob by positioning them in total darkness, starting the camera exposure, and illuminating them with my handheld flash. Then I carefully moved a flashlight in a straight line from Paul to Bob. For a finishing touch, I removed Bob from the scene and fired the flash again to achieve the impression that he was disintegrating.

For a modern update with a digital camera, here are some shots I took just this week with my daughter, who hasn’t been this excited to be photographed since the time we tried our hands at popping water balloons at high shutter speed. Here she is shooting beams of light from her hands.

And this one shows the kind of cool, unpredictable light trails you get as a result of random variations in the way you hold the flashlight.

Controlling the Light

Since this technique relies on you moving a flashlight around in the dark, clearly it’s not possible to get perfect results every time–that’s why I say you need to experiment. You can stack the deck in your favor if you remember to choose your camera settings wisely.

The shutter needs to be open for a long time, so that means the only aspect of your camera you really have control over is the aperture. If you use a small aperture (which equates to a large number, like f/18), the effect of the light will be diminished. A large aperture (small number, like f/4) will admit a lot more light, and that means any ambient light will illuminate the entire scene. But it also means the flashlight will appear brighter, and you might pick up ghost images of the person moving around with the flashlight. Start with an intermediate aperture, like f/8, and vary it to see how different values affect your photos.

Pointing the Flashlight

Finally, how you point your flashlight can give you dramatically different effects. I recommended that you point the flashlight directly into the camera lens, because that will give you the most immediate and dramatic result. But as an alternative, try shining the flashlight at objects in the scene instead. In a perfectly dark room, for example, you can experiment with selectively illuminating subjects. Good luck, and send me some of your best results.