Use Depth of Focus and Dark Cloths to Make Problems Disappear

How often have you been at to zoo or aquarium and been disappointed because your photos have annoying fences or glare that ruin the scene. Did you know that many professionals use a couple of simple tricks to make these distractions fade away? With a little understanding about your camera and some practice, you too can take photos that look as if you just got back from the African savanna or a South Seas coral reef.

Before I can divulge the secret to the magic disappearing act, we need to understand why the problems show up. Let’s take them one at a time.

Annoying chain link fences between you and the subject. No one wants these protective barriers to actually go away. I am not looking forward to an angry tiger asserting his right to eat my sandwich. But we can make it appear that the fence has been removed by using the focus range of our camera.

Cameras have an iris between the lens sections that opens and closes just like the iris in our eyes. When it is closed down to a small opening (or aperture), the distance from front to back that appears in focus is deep. When the aperture is wide open, the apparent range of focus is less. As an example, let’s consider that we are shooting a set of flowers in our garden. The flowers are spread out from front to back. The pansies are up front, tulips are behind the pansies, and the irises are filling the background. If we focus the camera on the pansies with a small aperture, the tulips and iris will also be in focus. This is called a wide Depth of Field (think “Depth of Focus”). I however, we change the aperture to its widest, the tulips become a little fuzzy and the background iris are just a blur of color with little detail.

So it seems that changing the aperture will make objects in front of or behind the main subject become ether clearer or more unfocused. In fact, it is possible to make objects in the very near foreground become so out of focus that they seem to disappear. And so now we have a way to remove that fence.
 

Setting Up the Shot Through a Fence

Here’s how to set up for the shot. First, if your camera has an aperture priority setting, use it. It will be on a large dial, often on top of the camera. Look for the letters “Av” (aperture value), “Ap” (aperture priority), or just the letter “A”. This setting tells the camera that you want to control the iris in the lens to insure a specific aperture. The camera will then adjust the shutter speed to insure the correct exposure. Set your aperture at the lowest number that your camera will allow, such as 2.8, 3.5 or 4.0. Keep away from the larger numbers like 5.6, 8, or 11. Next, position yourself very close to the fence with the lens centered between the links for the least obstruction. Focus on the tiger, or whatever else you wish to photograph. Take the shot. Look closely at the result. If there are slight remnants of the fence showing try using a dark cloth, jacket, or even just your hand to block the sun from shining onto the fence near the camera and try again.

Pocket Camera Problem

Now for the bad news! I often praise the ability of new pocket cameras to get awesome photos that used to require expensive cameras and years of knowledge. It is a fact that the introduction of digital sensors and computer chips into these small cameras have opened up the world of the professional to the average weekend photo hobbyist. But those big expensive cameras are still selling off the shelves. That's because there are some areas where they provide options that the smaller cameras still have difficulty. Depth of Field is one such area. Because of the very small lenses in pocket cameras, the control of focus is limited. Put simply; the smaller the lens, the more that everything will look clear even at large apertures even when you don't want. So if you stood next to a friend who is using a large DSLR with a telephoto lens attached, he would have more ability to blur the fence than you. But you still have a good chance and its well worth the effort. If you have a zoom control, use the telephoto end(Zoom in) of the range rather than the wide angle setting. This will also help decrease the Depth of Field.
 

Setting Up the Shot Through Glass

Now let’s talk about those ugly reflections when you shoot through glass, such as at the aquarium or of a diorama in the museum. Just as we used a dark cloth or jacket to hide the sun on the fence, we can hide the reflections from getting to the glass. Get close to the glass, set your aperture to its lowest setting if you want to also remove smudges or dirt from the glass. Then hold the jacket so that it is shielding the glass where the reflections show. Move it around to locate the best position, and take the shot. This technique is more suitable to all kinds of cameras because you are not relying on the camera’s features as much as your ability to block the light.

By the way, this tip can also come in handy for shooting from a moving car. A woman at one of my classes was complaining that her husband would never stop so that she could take photos. Her attempts at shooting through the windshield or side windows often revealed lots of close-ups of dead bugs. I ran into her a few days later and she showed me some great pictures that she got using this tip. I don’t know if it helped her marriage. But I’m sure that her family and friends will enjoy her vacations photos more.