What is a fisheye lens?
A fisheye lens is a special type of extreme-wide angle lens that shows a distorted, spherical view of the world, named after the way fish see. The fisheye effect we get when using this lens is one with curved outer corners in the frame and a distorted periphery. Why is that?
Most common lenses, like the regular wide-angle lens and others, are rectilinear. These lenses reproduce best what the human eye sees and capture straight lines as straight lines.
The reason for the fisheye effect is that the lens is curvilinear, causing barrel distortion that is very apparent around the periphery of the shot.
As fisheye lenses are extremely wide, they have a focal length between 4-16mm. The smaller this focal length, the wider angle of view it provides. A traditional wide-angle lens gives a field of view of 70-120°, but a fisheye can increase that up to 180°, sometimes even more! This massive angle of view allows you to get a close-up of your subject while simultaneously showcasing the landscape or background behind it. The close focus achieves great color and sharpness and allows you to shoot large objects from a lot closer than you could with a traditional wide-angle.
Types of fisheye lenses
Fisheye lenses can be grouped into two families: circular and full-frame fisheyes. A circular lens will project the whole spherical image onto the camera sensor, while a full-frame lens projects an image larger than the sensor. This leads to a non-circular photo with a field of view smaller than 180°.
Fisheye lenses for smartphones are popular gadgets for those who look to experiment on a budget.
How to use a fisheye lens
Many consider fisheye lenses a toy or gimmick. It’s true, they are excellent at creating funny and weird portraits – but that doesn’t mean they can’t be used to make a statement! They are great at creating unique, eye-catching images and exploring new perspectives.
The fisheye’s distortion means that small changes in framing will have a great impact on your composition and image as a whole. Try to keep your subject in the center of the shot to avoid distorting them. Locations where there’s not a lot of straight lines in landscape or architecture, or with naturally curved lines can easily minimize the barrel distortion, or even emphasize and play along with it. There are also post-processing techniques available to “defish” an image by lessening or removing distortion.
Fisheye lenses are usually cheap, light, and very easy to use. Simply put a fisheye in front of your sensor and look through the viewfinder to explore creativity in this new worldview.
Still on the fence? Check out these 7 reasons why fisheye lenses are awesome on Petapixel.com.