kalansilmäobjektiivi

Kalansilmäobjektiivi, known in English as a fisheye lens, is an ultra-wide-angle lens that produces a strong, visual distortion intended to create a wide, panoramic or hemispherical image. The name derives from the term "fish-eye," a view from the perspective of a fish in a bowl, suggesting a distorted, wide field of vision. These lenses achieve their extreme field of view through significant optical distortion, which results in straight lines appearing to curve, especially near the edges of the image. This distortion is a defining characteristic rather than a flaw and is often intentionally employed for artistic or specific photographic purposes.

Fisheye lenses can be categorized into two main types: circular and full-frame. Circular fisheye lenses produce a circular image within the frame, surrounded by black. Full-frame fisheye lenses, on the other hand, cover the entire rectangular sensor or film, though with significant barrel distortion. The field of view for fisheye lenses can range from 100 degrees to over 180 degrees, with some even exceeding 200 degrees. They are commonly used in astrophotography, extreme sports photography, architectural photography for dramatic effects, and in surveillance systems where a broad overview is required. Despite their distortion, they offer a unique perspective that can dramatically alter the viewer's perception of space and scale.