Lens flare results from pointing your lens towards a bright source of light. Direct light striking the glass creates flare in the form of colorful blobs. Although lens flare is often best avoided, you can use flare to make creative and expressive images. In this article, pro photographer Ian Plant shows you how to avoid lens flare, how to use it artistically, how to create a "sunstar" effect, and in a video available to PRO subscribers only, how to remove flare from your photos.
Lens flare results when direct light strikes the glass of your lens. It can manifest in different ways, including colorful blobs or a low-contrast glare, depending on lens and aperture choice. For this photo, I used lens flare creatively to give the image a warm, dreamy glow. Arctic National Wildlife Refuge, USA. Canon 1DXII, Canon 200-400mm lens, ISO 200, f/4.5, 1/800 second.
What is lens flare?
Lens flare happens when bright light strikes the front elements of a camera lens, producing (often) undesirable artifacts in the final photo. This happens as light reflects within the lens design itself or strikes imperfections in the glass. Complex lenses such as zooms tend to produce more flare. Lens manufacturers combat flare with advanced coatings and other technology.
There are, generally speaking, two types of lens flare. The first is a general "glare" that forms over part or all of the image frame, making the image look "washed out" by reducing contrast and color saturation. The second is noticeable artifacts that appear as colorful "spaceship blobs" in the final image. There are certain kinds of photography where this type of flare is acceptable, but with landscape and wildlife photography, this second type of flare especially is generally considered undesirable and best avoided.
Pointing the camera towards the sun often results in flare, especially when the light is very bright, such as with this photo where the sun was relatively high in the sky. The result are a bunch of colorful blobs that look like an alien spaceship invasion.
Avoiding lens flare
The easies way to prevent lens flare is to simply avoid pointing your lens towards bright light. Since I love shooting into the light, this isn't a very exciting option, in my opinion. If you aren't pointing directly at the light, using a lens hood can often be sufficient to prevent side light from striking the front element of your lens. You can also shade your lens using your hand or a hat. Dust or grease on the outside glass of the lens can produce flare, so it is important to keep your lens clean. Filters can also create flare, so if you are getting lots of bad flare when using filters, try taking them off to see if you get better results.
If shooting directly into the light, a lens hood or other shading method won't help. Your best bet to reduce or eliminate flare is to look for something to partially block the light (for example, using a tree trunk to partially block the sun). Also, timing can help reduce flare: when the sun is high in the sky, it will be more intense and flare will be more of a problem, but at sunrise and sunset when the sun is low in the sky, it won't be as bright and flare will be minimized.
Using flare creatively
For some types of photography, creatively incorporating lens flare is completely acceptable. Even with landscape and wildlife photography, you can use flare creatively, although typically you want to control the flare as much as possible to get "good" flare (the first kind of flare discussed above) rather than "bad" flare (the second kind which forms the blobs). For example, this is the same scene as photographed in the preceding image. The sun was high in the sky, just above the tall sand dune in the background and just outside of the image frame. The first photo had a lot of flare blobs, but for this second photo, I used my hand to partially block the sun. I didn't block it entirely, as I wanted to keep the resulting bright glare at the top of the composition, but I blocked it enough to eliminate the blobs.
I controlled the flare by partially shading the lens with my hand, which allowed me to eliminate the "bad" blob flare but keep the "good" bright glare at the top of the image, which creates a halo effect around my main subject. Namib-Naukluft National Park, Namibia. Canon 5DIII, Canon 24-70mm lens, ISO 100, f/16, 1/50 second.
Part of what creates the blob type of flare is shooting stopped down, especially with a wide-angle lens. Simply put, flare gets more distinct as you increase your depth of field. Lens flare is easier to control with longer focal lengths and large apertures. For example, I photographed this one-eyed lion with a long telephoto zoom with the sun rising over his shoulder just outside of the image frame. There was lots of lens flare, but because I shot this wide open with a telephoto lens (which essentially magnifies the flare), the flare was diffused over the entire image frame. The end result is a warm, "gauzy" low-contrast look for the image.
It's relatively easy to get "good" lens flare when shooting with telephoto lenses at wide-open apertures. Shooting with a large aperture minimizes depth-of-field, essentially throwing the flare blob completely out of focus, and telephoto magnification enlarges the flare over most or all of the image frame. The result can be dreamy and colorful. Masai Mara, Kenya. Canon 5DIV, Tamron 100-400mm lens, ISO 400, f/6.3, 1/400 second.
Commonly know as "starbursts" or "sunstars," this lens flare effect is achieved by including the sun in the picture frame. The sunstar effect is caused by light passing through the lens aperture and being diffracted across the aperture blades (arguably this technically isn't lens flare, but maybe we can call it "lens flare adjacent"). Sunstars look best using wide-angle lenses with small apertures; typically, f/11, f/16, or f/22 will produce the best-looking sunstars. Not all lenses produce attractive sunstars, and sunstar preference is a subjective personal choice. If you shoot a lot of sunstars, make sure to pick lenses that produce stars that you like, and that do a good job controlling lens flare.
When shooting sunstars, lens flare is an issue, and you want to be careful to avoid bad flare. This is often best accomplished by partially blocking the sun with a cloud, the horizon, a tree trunk, or some other object. You want to find that perfect "sweet spot" between having too much sun (creating lots of bad flare) and too little sun (no flare but also the sunstar effect is weak or non-existent). Often, there is no perfect compromise, and you will have to clean up any resulting bad flare when processing your photo, but usually you can minimize the amount of bad lens flare that creeps in, making clean-up easier.