Lens flare

Lens flare is the result of unwanted light entering the lens and hitting the image sensor. How the effect occurs depends upon various factors such as the number of internal lens components, lens focal length, aperture size and width, and the type of light source and its brightness (such as the sun, a spotlight, etc.).

Lens flare and ghosting can both have similar effects caused by unwanted light entering your lens at an extreme angle. This type of hazy look is a typical problem that is easily remedied by simply blocking the light or moving your position. (ISO 400, 1/160 second, f/10, taken with an EOS 20D and an EF24-70mm f/2.8L lens.)

Many higher-quality lenses have features that help deter flare and disperse light within the lens before it reaches the sensor, but, as with ghosting, virtually any lens is susceptible to flare given the right conditions. The appearance in the image is that of a series of geometric bright shapes that extend from a corner of the image toward the center, gradually increasing in size. They can look like starbursts, rings, or polygons that are a direct reflection of the lens’s aperture shape. Sometimes, it can simply be the effect of a hazy quality to the lens (see figure 5-1). Longer lenses and lenses with more complex optical systems and multiple elements tend to suffer from flare more severely than simpler, shorter ones; however, it can happen in virtually any lens given the right light conditions.

As with ghosting, using a lens hood or shading a bright light source can help avoid flaring. Sometimes it may be that you simply need to use your hand as a shield from the light, placing it just beyond the image border of your shot. Studio lights can also produce flare, but are easily moved or shielded by a hood or leaf (a flat panel) on the light housing. In figures 5-2 and 5-3, I had noticed that the studio light I was using caused some minor flare to enter the photo on the bright light source can help avoid flaring. Sometimes it may be that you simply need to use your hand as a shield from the light, placing it just beyond the image border of your shot. Studio lights can also produce flare, but are easily moved or shielded by a hood or leaf (a flat panel) on the light housing. In figures 5-2 and 5-3, I had noticed that the studio light I was using caused some minor flare to enter the photo on the upper-right side; I was able to close a panel on the light to block the light to eliminate the effect. Using a lens hood, even in studio shots, can also be helpful.

Lens flare and ghosting can both have similar effects caused by unwanted light entering your lens at an extreme angle. This type of hazy look is a typical problem that is easily remedied by simply blocking the light or moving your position. (ISO 400, 1/160 second, f/10, taken with an EOS 20D and an EF24-70mm f/2.8L lens.)


Tip

Sometimes the effect of lens flare can be interesting, providing an artistic quality to the photo.

Category: Science of Lenses

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