Lenses and light
From choosing the best aperture to waiting for the right light, these techniques will help you get pin-sharp results every time
MASTER SHA LLOW DEPTH OF FIE LD
Isolating your subject by blurring the background (and foreground) is one of the most effective ways that you can add impact to your shots. The contrast between the sharp areas and the blur can make the subject appear sharper, even if the sharpness is only relative.
Depth of field – how much of the scene is sharp – is affected by three variables; the focal length of the lens, the aperture you have selected, and your distance from the subject. To get a shallower depth of field you can use a longer lens, set a wider aperture or get closer to the subject – or a combination of all three.
Remember, though, that as well as blurring the background, you need to make sure that the depth of field is large enough to keep your main subject sharp.
CLEAN YO UR KIT
You can’t expect to get sharp results if your lenses aren’t spotlessly clean. Get an air blower, cleaning cloth and cleaning solution, and check the front and rear elements of your lenses regularly for dust, fingerprints or marks from condensation and water. Don’t leave your Nikon with the lens mount open for an extended period of time. When removing a lens, replace it immediately, or pop a body cap on the camera.
FOCU S A THIRD IN
A classic technique to ensure your images are in focus, especially in landscape photography, is to keep everything from the foreground to the far distance sharp. Try using a short focal length lens, such as 18mm on a DX-format Nikon or 24mm on a full-frame model, then set a small aperture, such as f/11, and focus a third of the way into the scene.
CHOSE THE OPTIMUM APERTURE
The sharpness of every lens will vary at different aperture settings, particularly at the edges of the frame. At the widest apertures most lenses are softer at the edges of the frame compared to the centre, while at very small apertures, such as f/22, the sharpness can suffer across the whole image due to an optical effect known as diffraction. Optimum sharpness is usually around two to three stops smaller than the widest setting, so f/8 or f/11 for a lens with a maximum aperture of f/4.
Test your own lenses by shooting a static subject from a tripod. Take shots at every available aperture, and check the results at 100% magnification to determine the best aperture to use. Then use this aperture to get the sharpest images, unless you need to achieve a specific depth-of-field effect or shutter speed for the lighting conditions.
Even though it’s not usually the most flattering light for many subjects, bright sunlight or flash can also make your shots appear sharper than shooting with a softer and more diffuse light. This is because the sharp shadows created by direct light reveal detail and texture in the subject, which creates an impression of sharpness.