When I started paying attention to the quality of photos I was taking, I started to really dislike every shot when I used the flash. Whenever the flash was on peoples faces were washed out (oftentimes with deer-in-the-headlights looks), and backgrounds went dark. I stopped using a flash altogether and instead decided I needed to buy really fast lenses and a camera with a big sensor, so I could take a picture in moonlight and still be able to see the details of someone’s face.

The thing is, you can have the best camera and lens in the world, and still take mediocre photos in low light. Cameras capture light, and when there isn’t any good light to capture, you need to make your own. A flash is really good at making light. So let’s lay down some ground rules.

Rule #1: Know when to turn your flash off.
If you are at a nighttime concert and are more than about 10 feet from the performer, turn your flash off. It’s not going to do you any good, and you’re just going to end up with an image of really bright people sitting in front of you with a performer all in shadows in the background. Countless bad photos are taken this way; just glance at the audience at the next Super Bowl halftime show. In this situation, your flash isn’t making any meaningful light for the scene (you are trying to light a stadium with a candle). Turn your flash off, and let your camera figure out how to get more light for your shot. Most cameras will struggle with the situation, but I guaranty you will end up with a better image.

Rule #2: Know when to turn your flash on.
A lot of people assume that on a bright sunny day, you don’t ever need to use a flash. This is simply not true. When you are taking shots in the harsh mid-day sun, you will have some really strong shadows in your image. When these shadows fall on the faces of the people you are trying to photograph, it’s not going to look good. You need a fill flash to “fill in” the shadows. Turn on your camera’s flash in these situations, and the shadows will go away, leaving you with a nice image. Better yet, find a nice shady spot to take your photo, and keep your flash on.

Rule #3: When you have a dark subject in front of a bright background, turn on your flash.
This happens most frequently when you have someone standing inside in front of a big window. The camera sees a bunch of light coming through the window, so it doesn’t trigger the flash. You are left with a silhouette of your subject. In this situations, you have two options. You can overexpose the image to brighten your subject and make everything outside the window look white, or you can turn on your flash. If you turn on the flash, your subject will be lit from the flash, and as a bonus you’ll be able to see the scene outside the window as well.

Rule #4: When you have a light subject in front of a dark background, consider turning off your flash.
This is where the deer-in-the-headlights look comes from. You’re taking a photo of a friend in a bar, and your flash fires to light up the person’s face. If you find yourself in this situation, it might be better to turn your flash off. If you turn your flash off, and can set the camera on something steady so the camera doesn’t shake, and tell your friend to hold steady (which might be difficult after a couple of drinks), you’ll probably get a better picture. The bonus here is that you will probably capture a lot more of the mood lighting, because you are relying on the bar’s lights and not your flash.

If you have a flash that has a swivel head, you might want to try bouncing the flash off a wall or ceiling. This will give you more even lighting around most of the scene as well as light your subject. Watch the color of the wall you are bouncing off of though, because your photo will take that color tone.

If neither of these two methods are working, try taking a few steps back and using your camera flash. This reduces the amount of strength of the light on your friend’s face and will lighten the background a bit, thus improving your photo.

Tip: A flash can be very useful in landscape photography
Most people assume a flash doesn’t really come into play with landscape photography. Most of the time this is true, after all you should be using a tripod in any low-light situation, so you don’t need the extra light. However, there are times when a flash really comes in handy. For instance, any kind of macro photography can benefit from a flash. Flowers become more radiant, and you’ll get quicker shutter speeds for close-ups of other objects (meaning less blur due to camera shake, when it doesn’t work to use a tripod). Flashes also come in handy when you are taking photos at night. For instance, if you are taking a wide angle shot of something on the ground, with a starry sky behind it, a flash can come in really handy. Take your long exposure, and fire the flash to “paint” the foreground a little brighter.

When should I get an external flash?
A few years back, I was going to attend a wedding and had to choose between buying a faster lens or an external flash for my DSLR. Being all too familiar with the washed out faces from a flash, I was leaning toward buying the lens. Luckily, some people online told me to go with the flash. I did, and got some really amazing shots at that wedding that I never could have gotten with the fast lens alone.

If you are thinking of buying an external flash, but aren’t sure if you’ll benefit from using it, stop reading right now and buy the flash. Buying an external flash (I have a 430EX II for my Canon) is one of the single best investments you can make to improve your photography. There is a learning curve, but if you take the time to learn how to properly adjust and bounce your flash, you will love the results. To make your life as easy as possible, make sure the flash you buy supports TTL (Through The Lens) metering for your camera. A lot of third-party lenses don’t, and while you can save some money going that route, it isn’t worth the extra headaches jumping straight into manual flash operation. With TTL, your camera controls your flash exposure so you don’t have to worry about it. Much, much easier. Later, you can always turn TTL off if you want to add your own creativity to the shot with your flash.

In the end, if you follow a few simple rules, you can greatly improve the photos you make. Just try to think about exactly what light your scene is lacking and, if the need arises, let your flash give that little bit of extra boost to make a good photo great.