Lens flare appears in photos in a pattern resulting from the aperture blades (diaphragm) of your camera. The diaphragm is a system of blades that open and close to control the amount of light that enters the camera. The aperture measurement on the camera refers to the opening in the lens and is usually measured in f-stops. The f-stop number corresponds to the size of the aperture; the larger the number, the smaller the aperture opening and the less light that enters the camera. The aperture can be adjusted on most film cameras and digital cameras with manual settings.
When you point a camera towards the sun, white- or yellow-tinged spots sometimes appear in the photo. These spots are a result of lens flare, which occurs when light streams into the lens at an angle and reflects between various parts of the lens. The light then reaches the camera's sensor (in digital cameras) or film (in traditional film cameras), resulting in the spots seen in photos. Flare is commonly a result of photos taken into the sun but can also occur from any bright light source.
There are a few basic things that you can do to prevent lens flare. Keep your camera clean. Minimize the objects that light can bounce off of by cleaning any filters and lenses with a lens cloth before you shoot. Cup your hand over the top of the lens or try using an umbrella or a piece of paper to block the light. If you plan to shoot outside or near bright light sources, you may want to buy a lens hood, which attaches to the lens and provides shade. Or change the composition of your shot; if your photo does not require standing in a specific position, place your back to the light. Not shooting directly into the light will reduce or eliminate flare. You can also adjust your angle and use elements in the shot to block the light source.
To prepare for a brightly lit shoot, there are a few different lens types that can aid in battling lens flare. Try a fixed focal length lens. Zoom lenses generally attract more lens flare because they have more parts, giving light more reflecting surfaces. Many wide-angle lenses also compensate for flare since they are frequently used for shooting expansive outdoor scenes. Several high-end lenses contain anti-reflective coating to minimize flare. If you do not want to invest in a new lens, consider purchasing a UV filter.
You can also try using lens flare to your advantage. Many modern photographers actually enjoy the effects of lens flare. Try shooting towards the sun or a light source (but do not point directly at the light source) using different framing and angles to see if you like the results of the flare. If you are shooting close up, use your subject to block the light, creating a silhouette effect. To make this effect work, you will usually need to shoot on manual mode to ensure that your subject is still well-lit. By experimenting with flare and light sources, you may find interesting results that complement your image.
- Digital Photography School; 5 Tips for Achieving Artistic Lens Flare; Christina N. Dickson
- Pop Photo; Tip of the Day: What is Lens Flare and What you can do About it; Popphoto Staff; December 2008
- Pop Photo, Picture Doctor: 4 Ways to Tame Flare; Dan Richards; December 2008
- Cambridge in Colour: Understanding Camera Lens Flare
- Photo Credit Roger Weber/Digital Vision/Getty Images