Control Depth of Field to Take Better Photographs

One of the biggest shifts I encourage my students is to make in their growth as photographers is to take control of the camera functions. In the early stages of shooting, many people rely on the camera's automatic exposure controls capability. They set the camera on Program mode, and shoot away.

One of the first steps in taking creative control in evolving your vision is deciding what the viewer's eye will focus on. Depth of field is one of the tools in accomplishing that. Simply put, depth of field is the distance in front of, and behind the point your focus on that is in focus. A photograph shot at a wide open aperture like f2.8 will have less depth of field than an image shot at a small aperture like f16.

In this example, my interest is in having the viewer look at the texture of the wooden buggy at a historical site. In the image above, the aperture is set at f2.8, so the focus is quite shallow. The background is blurred and the eye focuses on the corner near the wagon wheel. But in the image below, notice that using a small aperture of f16 allows the rocks and winter grass in the background to compete with the main subject because they are much sharper.



So my recommendation is that when you are making an image, think about what you want the viewer to see, and use depth of field as an ally to accomplish that.

Available light photography vs on camera flash

Most point and shoots have an auto flash setting so that when you are indoors, it simply guesses the best exposure. But that's not always the way to go.

For example, if your subject is near a window, you could raise the ISO setting, and shoot with the available light. The advantage is that unlike the small point source of the on-camera flash, you will have a large broad, palnterly light source.

And the second advantage is that instead of the flatness rendered by a light coming right from the camera (see the image below), you can position your subject so that you have directional lighting in the image. The result is that there is a more three dimensional quality to the photograph.



Obviously, this would not work if it were very dark inside, but when the light levels allow, try this technique for some lovely results.

Making good photographs in bad weather

Shooting on location is not all blue skies and dramatic color. Sometimes, you are in a great location, but the weather is bad. But should that stop you from looking for opportunities for images?

In fact, bad weather creates a whole new set of possibilities for pictures. And here's a good example. I was in New York recently, and the weather was overcast with rain showers. Certainly I could have just kept my head down under my umbrella and scurried from one dry interior to another.

But the wet streets and the shapes of the umbrellas of the passers-by was intriguing. And because the light level was so low because of the rain, I could shoot at slow shutter speeds giving me the opportunity to create a sense of activity and movement.

Getting great winter photographs

One of the challenges of getting great winter photographs is the lack of color in a snow covered scene. The world is mostly white with muted shades of browns, which can be exciting if you are shooting black and white pictures. But what if you are shooting color?

I find one of the best solutions is to shoot either at sunrise or sunset, where you get get the warm light associated with those times to add strong, dramatic accents to a colorless world. The added advantage of shooting sunrise is that there will be less footprints in the snow to break up the pristine quality of the scene.

WHAT TO PACK FOR A PHOTO TRIP PART IV

There are a lot of things I've been able to shed from my pack when I head out the door to shoot with a digital camera. Color compensating filters, for example, used to adjust the color of how film sees light in different conditions is easily replaced by one of two methods. You can either use preset or custom white balance settings in shooting to affect how the sensor reads the existing light, or shift the color in post production with the color balance adjustment layer in Photoshop.

But one thing I still carry for digital photography is my polarizer filter. Yes, there are some Photoshop plug-in filters that emulate it, but I still prefer to have the real thing in my camera bag. Why? Well, a polarizer is a great tool for making a sky look darker and richer than what the scene would look like without. The effect is particularly noticeable when you are shooting a subject that is in the shade, but the sky is still visible. That's because you are opening up the exposure from the full light exposure to capture detail in the shaded areas. But along with that, you are lightening the sky. Using a polarizer compensates for that overexposure of the sky, and makes it look more natural. Just compare the image above with a filter, to this image below that does not have one.



But be aware that a polarizer works at it's best when aiming 90 degrees from the sun. Shooting into the sun, or directly opposite will have no effect. In between, the effect increases as you approach the full 90 degree differential. In this example, I am shooting with the sun in the eastern sky close to sunrise, and I am shooting straight south.

WHAT TO PACK FOR A PHOTO TRIP, PART III

When it comes to lenses to carry on a trip, it's good to have a range so you can cover a variety of situations. And with today's technology, zoom lenses often come close to or match the quality of prime, fixed focal length lenses.

If you are shooting digitally, you want to keep in mind the camera sensor factor before choosing a lens. A 17-35mm lens for a full frame chip becomes a 27-56mm lens when used with a smaller chip with a 1.6X factor. That's a significant difference in coverage, and if you love to shoot wide angle, it's something to consider.



The same effect is a consideration when choosing which telephoto lens to take. A 70-200mm zoom becomes a 112-320mm lens when used with a chip with a 1.6X factor.

I always try to pack as light as possible, but insure that I have a bit more focal length range than I think I will need if I can fit the extra lens in my bag and am willing to carry the extra weight. I might think I am only going to be shooting broad landscape images that show scale and intimacy, but along the way, I might be surprised by a scene where a telephoto lens makes a more succinct statement, as the image at the top exemplifies.

TAKE GREAT PICTURES IN CLOUDY WEATHER

More often that we might like, we end up at a location where the opportunities for photographs are quite good, but the weather is not. An overcast sky that is uniformly grey can be a big damper in creating beautiful scenics, so what do you do?

One possibility, of course, is the shoot the scene and add a sky later in post production. Although this can be successful in some situations, you have to be careful that the sky you add looks believable.

The other option is to look for photographs that do not include the sky, thus eliminating the lackluster quality it brings to the image making process. The first thing I would suggest is to look for a composition that shows as much of the landscape as possible without including the sky.



This is also great time to hone your observation skills, and zoom in on details. Start looking for parts of the landscape that are interesting, things like streams, rock formations, flowers. All can be great subjects in the soft light the overcast sky provides. For example, the lower light level means you can shoot with slower shutter speeds to get motion blur in a stream. And the same soft light allows you to see patterns in rock formations without the harsh contrast (and shadows) created by a sunny sky.

Depth of Field

One of the most important concepts to understand is depth of field, which is the distance in front of, and behind the subject that will be sharp in relation to where you focus. The general rule of thumb is that the greater the ƒ-stop number, the more depth of field you will have. So, for example, at ƒ22 you will have a lot more in focus in front of, and behind your subject than you will at ƒ4.

The benefit of understanding this, is that different subjects benefit from using more or less depth of field. Landscapes, for example, benefit from greater depth of field because you can keep the foreground and background sharp. So you can keep a rock in the foreground in focus, as well as the mountains in the background.



But for portraits, the reverse is generally true. Although in environmental portraits there may be an interest in keeping the surroundings sharp, for the most part, we want to separate our subject from the background as much as possible. So shooting with a shallow depth of field is the way to go.



Just look at this portrait, taken on a basketball court. The important thing here is the personality and expression of the person, so allowing the background to go soft is a great solution.

But what if even shooting wide open (in this case, ƒ4) leaves some areas sharp because they are in the same plane of focus as the subject?



In this case, I duplicated the background layer, used guassian blur on the duplicate layer, then added a mask and protected the person’s face.



Look at the difference in this detail snapshot.





The result is that I’ve added more separation between the person, and the distracting pattern of the fence.

Texture

Here’s a fun example of how to use texture to create an interesting image.

I was walking along a trail in the redrock country of Utah, surrounded on all sides by big, undulating stone shapes. By themselves, of course, they can be wonderful subjects. But when I saw this dead tree coming up from a group of rocks, the contrast in texture was stark, especially against the clouds that added yet a third texture.

Another treat was that there were three distinct values of light and dark (white in the clouds, midtones in the rocks, and near black in the tree) so there was great contrast as well. You’ll also note that I am using the rule of thirds, both horizontally in how I place the tree off to the right, and vertically by having the tree top two-thirds up the image.

The result is a nice convergence of simple elements where texture can be the hero of the image.

Photoshop’s Recovery and Fill Tool

Photoshop CS3 has added two wonderful new features in Adobe Raw Converter. They are Recovery, for salvaging highlights, and Fill, for bringing out detail in the shadows.

Look at this example. The highlights are blown out, and the shadows plugged up. But by using the Fill slider, I was able to pull back information that seemed lost. And the Fill allowed me to pull a bunch of detail from the shadows.

Yes, some of this could have been handled a couple of other ways. I could have used Curves once the image was in Photoshop to help the shadows. Or, I could have done two conversions, one for highlight contro, one for shadow control, and then blended them as two layers in one file.

But with these new features, I can get a lot closer to where I want to be a lot faster, which means my workflow is improved.

Just take a look at the difference between the image above, which have the adjustments shown in this screenshot, and the image below that which is the straight conversion.



Here is the dialog box for the converter, with the settings I used.

Travels with Charlie

Taking a great picture of your pet can be challenging. Here’s one tip I think is important when your friend has both dark and light features.

Getting a good exposure can be difficult if you shoot with direct sunlight (either front or side lit) on your pet. That’s because with the extreme contrast in that kind of lighting situation, either the shadows will be too dark, or the highlights will be blown out. The image below is exposed for highlight detail, and look how the shadows plug up.

The better solution is to have your subject backlit. That reduces the contrast so the film or digital sensor can handle the range of exposure from shadow to highlight. Also, it will create some nice highlights in the hair or fur at the back edges, separating your pet from the background and adding a sense of depth. The top photograph shows that approach.

Just look at the difference in this portrait of Charlie. And just think how much happier he was without having to squint!