Lenses
A lens is typically composed of one or more optical glass elements, with basic units being concave lenses, convex lenses, or their combinations. Modern camera lenses also utilize aspheric lenses, which can be classified into ground optical glass aspheric lenses and molded plastic aspheric lenses. There are significant differences in manufacturing costs and lifespan, even when the imaging quality is generally the same.
Lens Classification (Cameras)
- Zoom Lens - A lens that can change its focal length
- Prime Lens - A lens with a fixed focal length
- Fisheye Lens - A lens with an extremely short focal length and a field of view close to or equal to 180°. A lens with a focal length of 16mm or shorter is generally considered a fisheye lens.
- Ultra Wide-Angle Lens - Typically with a focal length of 12mm-24mm
- Wide-Angle Lens - A lens with a focal length shorter than a standard lens (50mm), resulting in a smaller image compared to the actual object, creating a more exaggerated perspective.
- Standard Lens - A lens with a focal length of 50mm, which is close to human vision.
- Telephoto Lens - A lens with a focal length of 200mm or more, with a field of view of less than 12 degrees, creating a strong compression effect. Lenses with a focal length of 400mm or more are referred to as "super telephoto lenses."
- Reflex Lens - A special lens that uses two reflections of light to significantly reduce its length, characterized by excellent dispersion control.
- Tilt-Shift Lens - A lens that can adjust the perspective of the image or achieve full-area focus. Its primary function is to correct perspective distortion and achieve full-area focus, allowing both near and far subjects to appear clearly in the image.
- Macro Lens - Designed for microscopic photography, it has a higher magnification ratio and minimum focusing distance than regular lenses, making it suitable for capturing very small objects, such as flowers and insects.
- Teleconverter - Used to increase the focal length of an existing lens, primarily for use with telephoto lenses.