Address Movement in Close-Up Portraits
The closer you get to a subject, the greater motion’s effect on the position of your focal point, and the sharpness of your images. The slightest movement by the camera or the subject at such a close range can cause the focal point to be displaced, or the subject to be blurred during the exposure.
In order to produce sharp images with a controlled point of focus, you must address two factors, movement in the camera, and movement in the subject.
Even with your camera positioned steadily on a tripod, if your subject moves closer or farther from your camera between the time you lock focus and the time you take the shot, then your focal point is no longer consistent with the position of your subject. Here are some tips for preventing this dilemma:
Communicate with your subject. If you’re posing someone for his close-up, explain to him that too much movement will affect your focus. Ask him to remain as still as possible while you’re shooting. But, if you’re trying to capture a more natural look by letting the model move about during the shoot, have him make movements that are parallel to the camera’s digital sensor.
Parallel movements occur along the focal plane (the two-dimensional space parallel to the digital sensor that appears sharp in an image) and remain consistent with your point of focus. Movements toward or away from the camera cause the subject to move out of your plane of focus and become blurry.
Find the auto-focus mode that works for you. Most digital SLRs are equipped with an auto-focusing mode designed to produce sharp images when dealing with moving subjects (usually labeled as auto-servo, or AI Servo).
Your servo auto-focusing mode causes your selected point of focus to track the subject as it moves (between the time you lock focus and release the shutter). Refer to your owner’s manual for information on locating and setting your auto-focusing modes.
Pose your subject comfortably. If you’d like to minimize movement in your model, then pose her in a way that’s comfortable and stable. The less awkward the pose, the more likely she’ll be able to stay still for her close-up.