Saturday, July 31, 2010

Focus!


Desire

You can correct a lot of mistakes in digital photography. Depending on the software you use and your level of skill with it, you can straighten, brighten, adjust the colour and increase the contrast, soften your mother's skin and remove bird droppings from your new sports car, but there are a few things that no amount of Photoshopping are going to fix for you, and the first of these things is focus.

"Well", you say, "what about the sharpening feature in Photoshop?"

Well, I answer, all decent photo editing software comes with a sharpening feature (including decent photo editing software that doesn't cost more than a sports car), but here's the bad news: it only works if your pictures are already sharp to begin with.

Huh?

The sharpening feature in photo editing software doesn't really sharpen anything. What it does is increase local edge contrast, so that your pictures look sharper to the human eye. Software cannot make up information that isn't there; if you feed it a blurry picture, there's no amount of manipulation that will make it less blurry.

There are several factors involved in taking sharper pictures. Some of these have to do with the technical aspects of getting something sharp, and others have to do with getting the right thing sharp. So let's talk about the technical stuff first.

GETTING IT SHARP

First of all, the shutter speed has to be fast enough to "freeze" your subject, on the one hand, and prevent your own movements from blurring the picture, on the other. Neither of these things will usually bother you much when you're shooting outside in broad daylight; it's when you try to take pictures indoors or in low light that you're going to start noticing them getting blurry. Assuming that you're using one of your camera's automatic modes, that would be because the camera has to keep the shutter open for a longer period of time in order to get all the light it needs to take the picture. If your or your subject happen to be moving while the shutter is open, the camera will record the movement as a blur.

So how do you fix that?

The first thing to try is to set your camera to aperture-priority mode (check your manual), and use a wide aperture. (As a reminder, the widest aperture will be the lowest number.) With a wider aperture, your camera will be able to use a faster shutter speed, because the lens is allowing more light inside and the camera doesn't have to keep the shutter open for quite as long. Think of it as filling a bathtub with a drinking straw or a firefighter's hose; the hose will get the job done faster.

If your lens or camera has a vibration reduction feature built into it, turning it on will help to a degree. It also helps if you hold your camera properly, with your elbows tucked in and your body steady. If you can brace yourself against a fence, wall or tree, that will help as well.

If you've just bought your first DSLR and you're used to framing pictures by looking at the LCD in the back of a point-and-shoot camera, do yourself a favour and turn off the live view. Learn to shoot through the viewfinder like a crusty old film veteran. The only way you'll get any decent pictures by holding your camera at arm's lenght is by pure accident.

In very low light, or if you're taking pictures of a city skyline at night, you're going to have to use a tripod. There are thousands of models available from hundreds of manufacturers, at prices that range between $10 and several thousand. Which one you need depends on how much you're going to use it, but you should make sure in any case that the tripod you buy will be able to support the weight of your camera and lens. A lot of cheap tripods available in electronics stores are designed to support a small point-and-shoot camera, not a DSLR. If it wobbles, or if the lens "droops" after you frame your picture, you need a sturdier tripod.

GETTING THE RIGHT THING SHARP

Even if you're using a tripod in bright light and shooting a statue of Queen Victoria, your pictures will still look terrible if you get the wrong thing in focus -- like the trees behind Her Majesty instead of Herself.

Many digital cameras will give you the option to display an overlay in the viewfinder, showing among other things the focus point the camera is using. It's a good idea to turn that feature on, and learn how to move the focus point around the frame if that option is available to you.

Most digital cameras have several focusing modes available. Many of them will have a matrix focusing mode that tries to figure out what your subject is; other modes will focus on the object that's closest to the camera, which can be useful in many situations, but not always. If you're taking a picture of your daughter as she stands behind a hedge, for instance, you don't want the hedge to be sharp and your daughter out of focus.

Take some time to read through the section in your manual that describes the various focusing modes, and experiment with each of them. If you have the time and inclination, set your lens on manual focus and experiment with that as well. There will be some situations where autofocus is either difficult or impossible, and it's a good idea to get comfortable with trusting your own eyes.

And speaking of eyes, that's what you should be focusing on when taking pictures of people or animals. Whether or not the eyes are the mirror of the soul is beyond the scope of this blog, but I can tell you without a doubt that getting your girlfriend's nose sharper than her eyes will get you no brownie points whasoever.

ADDITIONAL RESOURCES

Photocritic.org has an article here that provides 8 steps to taking sharper pictures.

Photographer Nasim Mansurov has an excellent article here.

NEXT WEEK: COMPOSITION

Tune in next week for a discussion of picture composition, or how to take photos that look interesting and dynamic.

Happy shooting!

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