One photographic technique can both captivate and disorient us. It can twist a baby into a wide-eyed, big-mouthed gargoyle, but can also render a panoramic night sky in striking detail. It's graced CD covers and countless advertisements, and is even being put to use to make our roads safer. The fisheye lens has a name you won't easily forget. And when this unique creative tool is used well, it can produce unforgettable images that bend our perception of reality.
Ask any professional photographer or amateur enthusiast and they'll tell you that there's an almost endless variety of lenses on the market. From ultra-long telephoto lenses that can capture wildlife from hundreds of yards away to wide-angle lenses designed to grab an entire landscape in one click of the shutter, a shooter with enough resources could have one lens for almost every situation she encounters.
Most of these lenses have a rectilinear design: Light entering the lens travels in a nearly straight path to the film or sensor (though all lenses are slightly curved). This renders straight lines as they appear in real life, wherever they are in the scene. Wide-angle lenses have short focal lengths, which is the distance, when a lens is focused on the farthest point possible, between the optical center of the lens surface -- that is, the point in the lens, often at its center, where there is no distortion of light passing through it -- and the film or sensor that receives the image. Short focal lengths allow wide-angle lenses to capture a wide angle of view. The edge of the image is stretched far to the left, right, top or bottom of the center of the captured scene [source: Atkins].
But while wide-angle rectilinear lenses can capture angles of view approaching 100 degrees, fisheye lenses can stretch that to 180 degrees -- impossible to do without the light-bending science they employ. The tradeoff is distinct: Straight lines anywhere but dead center in the fisheye image appear to curve. The farther they are from center, the greater the curved distortion. This offers fun artistic avenues to explore, but it's also very useful. Some of the earliest fisheyes, for example, were built by astronomers to capture images of the starry night sky. In the digital age, these lenses allow one security camera to monitor a wide swath of property without moving, and automakers employ them as tiny backup cameras to help drivers stay safer on the road [source: Hughes].
What is a fisheye lens?
The term "fish-eye" actually predates the lens of that name. Physicist R.W. Wood presented the term in a 1906 article, "Fish-Eye Views and Vision Underwater." The hobby of keeping fish as pets was booming, thanks to the development of early home aquariums, and Wood offered a scientifically based description of how pet fish might view the world outside their glass tanks [sources: Kingslake; Lomography].
To understand what Wood described, take a chopstick and stick it into a glass of water. The straight piece of wood will appear to bend where it enters the liquid; this is an illusion caused by refraction, light bending as it goes form one medium (air) to another (water). This is the fundamental phenomenon that allows a fisheye lens to reach far to the sides of a scene and pull in the visual information at the edges of the frame.
Whereas a rectilinear lens is designed to behave like a window as light moves as straight as possible through its series of elements, the fisheye lens uses its elements like a funnel, bending a wide angle of light captured by the extremely curved outer element of the lens toward the film or sensor inside the camera. The fisheye's signature distortion comes from this funnel-shaped path: Light at the edges of the frame has to bend further to reach the film or sensor, resulting in greater distortion [sources: Atkins; Kingslake].
Lens maker Beck of London produced the first fisheye lens, labeled a "whole-sky lens," in 1924 for meteorologists and astronomers. As the name implied, the lens was intended to capture wide swaths of the sky in one shot. Scientists could then use geometric principles to account for the distortion, allowing them to measure the distances between and sizes of objects captured in the image. Other manufacturers followed suit over the next several decades, producing lenses with wider angles of view and greater clarity, with Nikon releasing the first interchangeable fisheye lens for 35mm cameras in 1962. This lens measured 8mm (the focal length) with an F/8 (the maximum aperture, or how wide the shutter can open to allow light through to the camera's film or sensor), and it brought fisheye photography to the consumer market. Hobbyists and professionals alike began to explore artistic ways to make use of this lens' signature distortion [source: Lomography].
Taking Effective Fisheye Photos
Using a fisheye lens can be a little confusing at first. You're used to seeing straight lines rendered straight in your images, so the composition you envision in your head may not be anywhere close to what appears when you view the image the camera takes. The only part of the scene that doesn't suffer sever distortion is what's directly in front of the lens. Keep this in mind if you're trying to capture a face, figure or other sharp subject in the distorted scene you're capturing.
Like any photographic effect, the distortion that may throw off your early compositions can work to your advantage as you get used to the lens. Experiment with photographing geometric subjects such as bridges, towers and other spidery objects. Since the fisheye lens has variable amounts of distortion, slight shifts in camera position can produce a range of images.
Shooting fisheye images on a sunny day, or near a strong light source, presents another unique challenge. It's harder to keep the strong light from causing flares in the lens, as happens when you aim a rectilinear lens at the sun. Again, experimentation will help you determine how to adjust exposure to compensate for this issue; you may even find that it adds a dramatic element to the image you're trying to capture [source: Dargaud].
Once you have the photo, you'll have to consider another signature characteristic of the fisheye lens: Even though your camera uses a rectangular sensor or piece of film, the image will come out as a circle. Remember, you're seeing the rays of light that were funneled into the lens rather than those captured straight-on by a rectilinear lens. You may decide to crop your image to a rectangle or square, or could keep it spherical to preserve the full effect of the heavy distortion around its rim. Either way, your artistic sensibility and vision will be the guide for how to best present the final images.
While considering your final presentation, it's worth it to note that the digital editing that can turn a rectilinear lens into a fisheye-esque shot can work in the other direction as well. Most photo editors include some type of straightening filter, which identifies distorted straight lines and flattens them. While the end result will still have more distortion than an image shot with a rectilinear lens, it will showcase the ultra-wide angle of view that gives the fisheye lens a guaranteed place in the gear bags of many photographers.
Photography's dual nature fascinates me. True, a painter can capture a scene in a range of ways, from dead-on reproduction to work that is unrecognizable but for the emotion it evokes. The writer can describe a moment in journalistic prose, or can light his words on fire with the rhythms, links and patterns of poetry. But no other medium can perform photography's Jekyll-and-Hyde trick: one click of the shutter catches a discrete moment in time, exactly as it happened, while a simple change of lenses and another shutter click alters a scene into a distorted other-world, as far removed from reality as a Cubist painting.
That's what makes fisheye lenses and other extreme lenses -- such as high-end macro lenses -- so interesting to me. These finely tuned devices don't just let us capture the world around us; with practice, they can let us twist the reality in front of us to better translate the deeper messages that inspire us to frame the scene and click the shutter. They're powerful tools when used right, and happily, the journey to becoming an effective photographer is as enjoyable and fulfilling as it is long.
- Atkins, Bob. "Field of View - Rectilinear and Fisheye Lenses." March 20, 2012 (March 20, 2012) http://www.bobatkins.com/photography/technical/field_of_view.html
- Dargaud, Guillaume. "Fisheye Photography." Dec. 23, 2011 (March 24, 2012) http://www.gdargaud.net/Photo/Fisheye.html
- Hughes, C. et. al. "Wide-angle camera technology for automotive applications: a review." IET Intelligent Transport Systems. July 4, 2008 (March 20, 2012)
- Kingslake, Rudolph. "A History of the Photographic Lens." Academic Press. Oct. 28, 1989 (March 24, 2012)
- Lomography. "Fisheye: Rumble in the Pond." June 17, 2003 (March 24, 2012)
- Wulff, Henning. "A better view in fisheye land." March 13, 1997 (March 20, 2012) http://www.markerink.org/WJM/HTML/fishyfaq.htm