Digital Photography Hacks [Electronic resources] نسخه متنی

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.