Hack 44 Eliminate Glare in Reflective Surfaces

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Hack 44 Eliminate Glare in Reflective Surfaces

You've probably felt the frustration of trying to take a picture of a reflective object, such as a framed painting, and getting glare. The secret is to add another flash .

Using two external flashes instead of your camera's built-in unit offers all sorts of new photographic possibilities. As discussed in [Hack #43] , you can produce great-looking portraiture with just a couple electronic flashes and light stands. Here's another use for this capability: photographing reflective surfaces without producing glare.

As you know, when you try to use your camera's built-in flash to take a flash picture of, let's say, a painting on the wall, you always get a hot spot somewhere in the image. You could turn off the flash, lug everything outside, and then use natural light, but that's not always convenient either, such as when it's night. Plus, if you're shooting a lot of different objects to sell on eBay, do you really want to be standing outside with your equipment all day?

Try this method instead and work comfortably indoors. Hang your artwork on the wall and get your flashes and light stands together [Hack #43] . For this assignment, you won't need the photo umbrella, but you will need both the flashes mounted on their light stands.

Raise the light stands so that the flashes are the same height as the painting. Now, position one on the left and one on the right, each at 45 angles from the painting. The flashes and painting should form a triangle.

Mount your camera on a tripod and extend the legs so that the camera is the same height as the center of the painting. Make sure the camera is level and centered between the two flashes. Now, focus and take a picture.

Both flashes will go off, but amazingly, there's no light reflection in the picture! Magically, each flash cancels out the reflection from the other (see Figure 4-12). You get an evenly illuminated image with no hot spots.

Figure 4-12. Two flashes at 45 angle for no reflection

You can also apply this technique to tabletop photography for items such as flower vases and glassware. The main thing to remember is to keep your light sources at strict 45 angles from the subject, and keep the camera centered between them.

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Hack 45 Freeze Action with Electronic Flash

The hand is quicker than the eye, and your electronic flash is faster than your shutter. Use it to stop time and capture that magic moment .

The shutter on your camera can reach speeds of 1/2000 of a second or faster. The faster the shutter speed, the easier it is to stop action that is, freeze your subject in its tracks or, in the case of Figure 4-13, in mid flight. The challenge with a fast shutter speed is that it also severely reduces the amount of light passing to the image sensor. So, you have to either open up the aperture all the way (f-2.8 or so), increase your ISO speed (to ISO 400 or more), or both. And even then, you still might not have enough light to capture the picture.

Figure 4-13. A hummingbird captured in flight with flash

But there's a workaround for these limits imposed by the laws of physics. Your camera's electronic flash is an excellent tool to stop action when you don't have enough light to use a super-fast shutter speed.

In fact, even when you do have enough light, you still might want to use the flash. Why? Your camera's shutter probably tops out at 1/2000 of a second or so. But the electronic flash is just getting warmed up at that speed, and some external units can emit bursts of light as short in duration as 1/50,000 of a second. Now that's high-octane performance!

And it gets even better. Since the flash adds light to the scene, you don't have to fiddle as much with aperture and ISO settings. It's rare when you get to have it all in photography, but this is one of the few occasions where that's possible.

To use this technique, you first have to make sure the flash fires. If you're outdoors, switch to Fill Flash or Flash On mode. Now, make sure you're within range of your flash. For most built-in units, this means eight feet or closer. You can extend this range if your camera accepts an external flash, which is more powerful.

If you're using a point-and-shoot digicam, you're still going to have to deal with shutter lag : the delay from the moment you press the shutter to when it actually fires. You'll have to anticipate the decisive moment and shoot accordingly . Digital SLR shooters have more responsive cameras and don't have to compensate nearly as much for lag. Get to know your camera, and go from there.

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