Fisheye lenses come in two varieties. Both types create a heavily barrel-distorted image that provides a roughly 180 degree field of view. Circular fisheyes create a circular image that falls entirely within the frame, leaving black around the edges. The circular image covers a full 180 degrees in all directions. Diagonal fisheyes, which fill the frame, give a 180 degree view only along the frame's diagonals. With both types, a crop-frame camera such as a Canon Rebel or 50D will reduce the field of view significantly unless the fisheye lens is specificially designed for a crop-frame sensor. This will have the effect of significantly reducing the fisheye effect, which is at its most dramatic around the edges of the image (precisely the area lost by crop-frame sensors).
The EF 15mm f/2.8 is a diagonal fisheye designed originally for 35mm film cameras, and now usable on full-frame cameras such as the Canon 1Ds or 5D. It is one of the oldest SLR lenses that Canon still manufactures: it was introduced in 1987 as one of the first generation of EF-mount lenses, and does not seem to have been updated at all in the intervening 22 years, even as most of its siblings have been replaced by newer designs.
It is a fairly compact, lightweight lens with a metal mount and a plastic shell. Build quality is fairly typical of Canon's mid-range consumer lenses. A small petal-shaped hood is built in and cannot be removed. Because the front element is convex, there are no threads to mount filters in front, though gel filters can be mounted in the back. The front lens cap, oddly, is only held in place by friction, but so far I haven't seen it fall off.
Auto-focus is provided by the Arc-Form Drive (AFD) motor that was standard in the early EF lenses, which is somewhat noisier than more modern technologies. Fortunately, it doesn't have to move very much to focus, so it still manages to focus pretty quickly. The manual-focus ring spins freely when the lens is in auto-focus mode.
Image sharpness, contrast, and color are quite good, and the lens can focus down to 20 cm (about 8"), which allows for the kind of dramatic perspectives that fisheye lenses are famous for. There are some chromatic aberrations around the edges, but these can be easily corrected in software if you're shooting digital. Every once in a while, when the sun is just out of the frame, I will see a bit of flare, though oddly this never seems to happen when the sun is actually IN the frame.
With only five aperture blades, the lens cannot be expected to deliver pretty out-of-focus highlights; on the other hand, a 15mm lens has naturally deep focus, so it can be a challenge to get anything far enough out of focus that the highlights matter. In practice, this is hardly ever a problem.
This is a fun lens that makes high-quality pictures. Despite its rather outdated design, it does a good job and I recommend it.
0 comments:
Post a Comment