Minimize Depth of Field for Selective Focus

A lot of depth of field is a great thing if you want everything in your pictures to be in sharp focus. But there are times when you might want to limit or restrict depth of field so that only your main subject is sharply focused and the background and/or foreground is less sharp. The main reason for doing this is to accent your primary subject--in a head-and-shoulders portrait, for example--where you want your subject's face in sharp focus but want to toss the background into a soft blur.

You can reduce the amount of depth of field by simply reversing the things we talked about in the previous tip. Again, here are the primary factors:

• Lens focal length: The longer the focal length of the lens, the less depth of field you will have at any given aperture (f/stop) and at any given distance. As you zoom a lens from wide to telephoto, for example, you quickly lose depth of field (provided you are keeping the aperture the same, see below). I used a 70-300mm Nikkor AFS lens at the 300mm position (450mm in 35mm terms) to shoot this horse on the King Ranch in Kingsville, Texas partly because I needed the long lens to bring the wild horse close, but also so that I could throw the foreground scrub and background out of focus.
• Lens aperture: The wider the aperture (again, assuming focal length and subject distance are constant) the less depth of field. You will get significantly less depth of field at f/4 than at f/16, for example. Think "smaller" f/stop numbers = larger lens openings = less depth of field. Remember, this does not affect how sharp your subject will be if you focus carefully, the larger aperture only reduces the near-to-far sharpness.
• Subject distance: The closer you are to your main subject, the less that will be in sharp focus in front of and behind the subject. Want less depth of field? Move closer. Want more? Get farther away from your subject.
  

So, if you were shooting a portrait of a friend sitting on a bench near a harbor and just wanted the person sharply focused with the boats in the background recorded as a soft impressionistic blur, you could choose a wide aperture and a long lens. You'll be able to see the results of your depth of field experiments on the LCD when reviewing the shot, but you won't see them if you're composing on the shot live on the LCD because the lens is not stopped down to its shooting aperture until you actually shoot the photo. (If you're using a DSLR with a depth-of-field preview button, you can use that feature to check it, but the viewfinder gets so dark that it's often hard to tell the difference.)

Keep in mind, if you're shooting with a point-and-shoot camera, you'll have less control when it comes to restricting depth of field because they tend to have inherently smaller apertures which (you knew this already!) creates more depth of field.

Finally, if you're shooting in bright light and the camera won't allow you to use a wide aperture, even at a high shutter speed, you can use a neutral-density filter in front of the lens to reduce the light. These filters won't affect color but reduce the amount of light entering the lens. I'll write a tip of "ND" filters in the future.

Maximize Depth of Field for Ultimate Sharpness

There are really two kinds of sharpness in a photograph. One is the sharpness of your main subject, say, a person standing on the beach and that sharpness depends on how steady you were at holding the camera, the shutter speed you used, how carefully you focused on your subject and how still your subject was standing. If you are careful with your technique, your subject should be quite sharply focused.

The other is depth of field or "near-to-far" sharpness and that describes how much of the beach in front of and behind your subject is also in sharp focus. Depth of field sharpness is not an absolute thing that has exact starting and stopping points, rather it's a zone of what is called "acceptable" sharpness. Ultimately how sharp a photo appears also depends on where you're seeing it and how far away you are from the image. If you're looking at an online version it will often look sharper than it will in a print, largely because a print is made of paper and ink and has a surface that can interrupt our interpretation of sharpness. Also, images online are rear-illuminated so they will always look brighter and, within reason, sharper. And if you're looking at a print, the farther you are from the print, the sharper it will appear (particularly if you refuse to wear your reading glasses).

But you can maximize depth of field, that zone of acceptable sharpness, if you know what factors affect it. Basically three things (in combination) determine how much depth of field sharpness an image will have: lens focal length, your distance from the subject and the aperture you're using. Here are some things to keep in mind when you're trying to maximize depth of field:

• Wider lenses have inherently more depth of field. That means that for a given f/stop at a fixed lens-to-subject distance, the shorter the focal length of the lens, the more that will be in sharp focus. Wide-angle lenses provide the most depth of field and telephoto lenses the least.
• With any given lens, the smaller the aperture (f/16 as opposed to f/4, for example) the more depth of field you'll get.
• With any given lens at any given f/stop, the farther you are from your subject, the more depth of field you will have. If you were shooting a picture of a friend with a 28mm wide-angle lens at f/8, for example, your photo would have inherently more depth of field if you stood 10 feet away than if you stood five feet awy.

Remember, it's these three factors in combination that really determine depth of field. If you're photographing a landscape and want lots of near-to-far sharpness, choose a wide lens and a small aperture and you will increase depth of field. I shot this photo of Las Olas Boulevard in Fort Lauderdale using a combination of a wide-angle lens and a very small (f/20) aperture to wring the maximum amount of sharpness from the image. Because you're usually using small aperture to get a lot of depth of field, you'll also be using relatively slow shutter speeds. In order to be able to shoot this photo at such a small aperture, I had to reduce the shutter speed to 1/30 second. You can see the motion blur caused by the slow shutter speed in the pick up truck. Using a tripod helps to steady the camera, but you'll still get blur with any moving subjects.

Of course, there will be times when you want to minimize depth of field--to limit sharpness in a portrait, for example, and to do that...you'll have to read the next tip!

Compose with Odd Numbers (Don't Ask Me Why)

You probably wouldn't think it would matter how many of something you have in a particular photo, but whenever you're composing a group of things, whether it's pears, people, polar bears or pretty much anything else, compositions seem to work best with odd-numbered quantities. None of the composition books I have seems to offer a really solid reason why that's so (file it under "minor mysteries of the human brain"), but I think it's a good rule to follow. Whenever I'm arranging objects in a found still life or composing a landscape (three trees, five horses, etc.), I almost always seem to gather things in groups of three or five. There were about 50 sailboats in the harbor when I took this shot, clustered in little groups, some odd, some even, but the groups that looked best in the viewfinder always had odd numbers in them. Strange, isn't it? I think part of the problem with even-numbered groups is that the eye can easily divide the subjects into pairs and it starts to divide up the frame on some subconscious level. But whenever there are threes or fives, for example, they seem to adhere to one another in a way that unifies them. Try it sometime. Photograph groups of apples on your kitchen table and see if you like the odd groups better than the even ones. And if you figure out why the odds look better, let me know.

Shoot What Interests You

When it comes to deciding if a subject is worth photographing or not, I think a lot of people (including most professionals) run the idea through a mental filter: Is this subject interesting or good enough to spend time photographing? Don't filter yourself. The one criteria you should use in deciding whether or not to photograph something is if it interests you. If something calls you and makes you want to photograph it, don't listen to the critics in your head, just listen to your imagination. These are, after all, your pictures and you get to decide what makes a good photograph. If you critique your ideas too much before you shoot them, you'll only stifle your imagination and give yourself another reason not to haul out the cameras and tripod and make the effort.

I grew up in a suburban part of Connecticut that wasn't far from a much more rural area. Because I didn't spend much time in the rural areas as a kid, I was always fascinated by them. I'm sure if I had grown up on a farm I might not find cows and tractors and old bars quite so fascinating--or maybe I still would, who knows. But farms and farm machinery have loomed large in my imagination since I was a kid and when I got to Iowa the first time a few years ago and saw huge grain elevators with their own private railroad sidings, I was totally intrigued. I spent several days just wandering down dirt roads (look at yesterday's posting for one of those shots) and photographing things like corn cribs, forgotten barns, ratty old farm fences and just about ever silo that I saw.

I shot the photo here in the picture-perfect town of Prairie City, Iowa. In fact, this tractor is sitting in front of a few huge grain silos just a short walk from the town center. By the time I got there the light was beginning to fade (you can see the last splash of daylight on one of the big silos) and a deep shadow had fallen across the tractor. I shot several photos anyway knowing that I could probably save the shot in Photoshop--which is exactly what I did. In fact, getting a decent image from the original file was kind of a challenge (I could write a entire article on the 30 or 40 steps I used to get a good finished file), but because I loved the subject so much, spending time with the image was fun. I just put on some Greg Brown music (he's an Iowa folk singer) and tweaked to my heart's content.

The most important audience you'll ever have for your photography is you. If your photos don't excite you, if the subjects don't stir your imagination, you'll have a hard time inspiring someone else with them. I think the love you have for your subjects and your fascination with them ultimately becomes part of their power. I can't imagine anyone putting "industrial tractor" at the list of their favorite photos subjects, but I think there is a quietness and an intimacy to this shot that others can appreciate. And any time I can document a piece of fading America, I feel that's a worthwhile ambition to serve.

These are the Greg Brown lyrics I was listening to as I edited this image. I'm sure I heard them in my head as I was shooting, too:

Now the railroad came generations ago
And the town grew up as the crops did grow
The crops grew well and the town did too
They say it's dyin now and there ain't a thing we can do
I don't have to read the news
Or hear it on the radio
I see it in the faces of everyone I know
The cost goes up
What we made comes down
What's gonna happen to our little town

"Our Little Town"
Lyric copyright Greg Brown

Keep a "Places" Journal (And Stop Losing Those Pretty Red Barns)

For a travel photographer, one of the most frustrating things in the world is to find a great photo location and then lose it. I know, because I've done it a lot. The problem is that I like to wander a lot, especially when I'm exploring someplace new, and since I'm concentrating more on things like finding interesting shots, waiting for great lighting and wondering where I'm going to stop and get a burger, I often forget to make notes about exactly where I was when I shot the pictures. A few weeks later I'm back home and editing photos and scratching my head looking at maps trying to piece the trip back together again.

A far better way, of course, is to just keep a notebook handy in your shooting vest or on the dash of your car and keep notes and directions for re-finding locations. I don't go back to the same places all that often, but there are certain pretty places, like this red barn in Iowa, that I would love to shoot again (perhaps in a different season) if I was back in that part of Iowa. I know roughly where I shot it and I can picture the road in my head, but I'm not at all sure I could find it on a map. Had I just written down the route number and the nearest cross street, finding it would be a breeze.

I'm sure that in the next few generations of digital cameras there will be geotagging/GPS included in the EXIF data and keeping a road journal will be a thing of the past, but for now, it's worth writing down where you were when you shot some of your favorite pictures. Besides, while GPS might be a cool techno thing to play with, it's not like you can stuff theme-park brochures or diner menus into it the way you can with a notebook or journal. And if you're going back to the same area to photograph you'll definitely want to remember where the best burgers in town were...though to be honest, I rarely have trouble remembering that.

Create a False-Color Infrared Look

Way back in the pre-Photoshop days, photographers who wanted to get experimental with color had to get somewhat inventive in their technqiues. And since many of us grew up in the 1960's and were influenced by artists like Peter Max, we went to some pretty great extremes to intentionally scramble colors. The simplest method was to put colored filters over the lenses, but some photographers got more extreme and tried methods like duplicating negatives and slides (often through many generations) and filtering them during duplication, cross-processing film (developing slides films in chemistry meant for color negative films) or just messing around with colors in the darkroom.

One other option that a lot of us experimented with was a film called Kodak Ektachrome Infrared Film. This film was called a "false color" film because it included a layer that was sensitive to the infrared portion of the spectrum (invisible to humans) and so the way that the film responded and the colors it produced could never be predicted. By using filters over the lens you could further mix up the already off-beat color palette. The colors were wild too: foliage often took on a magenta color, greens became bright yellow and the skies would range from magenta to brilliant pink or yellow/green, depending on what filters you used and what the atmosphere was doing that day. It was a blast. Unfortunately, Kodak stopped making the film a few years ago and unless you have some stored in your freezer, the film is history.

There's a simple way to recreate the false-color look in Photoshop (I'm sure you can do it with other editing programs, too), however, and it's a lot of fun to play with. All that you have to do is open an image and then call up the hue/saturation tool. By sliding the hue to extreme positions, you'll see the colors go through all sorts of wild combinations. That's exactly how I created this shot of St Patrick's Cathedral in New York. Once I had a color shift that I liked, I used the saturation tool to pump up the colors a bit more and then went into the selective color tool and adjusted individual colors (in this case I adjusted the magenta layer to add even more magenta to the sky). As a final step I used the noise filter (Filter>Noise>Add Noise) to add some noise to give the shot a slightly more realistic film look.

For some reason the hue shifting that you can create in Photoshop resembles the Infrared look a great deal and playing with it is kind of like a flashback to the basement darkroom I had during high school. If you'd like to see how pictures shot with the film really looked, take a look at the Flickr Color Infrared Pool. The great thing about experimenting with ideas like this is that there is no right or wrong so you can't make any mistakes and the results are always unexpected and fun.

Don't Settle for Your First Impression

Finding a potentially interesting photograph is a pretty exciting moment for most photographers since it's the reason that we own cameras and spend our free time picture hunting. Once you've found a subject with promise, however, it's important that you push past the first flush of attraction and take time to "work" the subject a bit. Refining the shot and looking more closely at what attracted you to a subject really helps to simplify and strengthen compositions.

Often what attracts you to a scene is a clash of color, a particularly interesting bit of lighting or perhaps just a interesting shape or texture. In the case of this bright yellow rope that I found on a dock in Camden, Maine, it was pretty much all of those things: the bright yellow rope, the bright but soft late-afternoon lighting, as well as the shape and texture of the coiled nylon rope. The first few shots I took (top photo) were somewhat predictable: I included the entire coil of rope, as well as some of the dock and the water. I actually left the dock after shooting those first few photos and returned a few minutes, nagged by that voice in my head that tells me I haven't looked hard enough yet.

When I returned to the rope, I began refining the composition by finding a more directly overhead view (which meant leaning out somewhat precariously over the dock from the gangplank I was standing on) and by zooming in more tightly with my 18-70mm Nikkor zoom (a great little lens that came with my D70s kit). By extending the zoom almost all the way (93mm in 35mm equivalent) I was able to crop out all of the excess baggage from the left side and lower parts of the frame. Finally I played with the angle of the dock in the viewfinder until it created that nice diagonal line. I still like the first photo a bit, but I feel the second image is much more graphic and dynamic.

Normally I would shoot this type of scene with a tripod, but because I was hanging out in space somewhat I wasn't able to use one. Fortunately there was enough light to shoot at 1/250 second while still using a relatively small aperture (f/11) to get the depth of field that I wanted. By the way, if you look carefully, you'll notice that the shadow of the cleat (upper right) has become substantially longer and more gentle in the second shot--an indicator of how long I spent trying to find the best shot.

Take time to work the subject and you'll give yourself a lot more options in editing and printing and as I say so often, it's free, so what the heck.