objektiiv

Objektiiv is a term used in Estonian and some other languages to denote an optical lens or objective element that forms images by refracting or reflecting light. In photography and imaging, an objektiiv refers to the lens assembly mounted on a camera; in microscopy and telescopy it denotes the objective lens closest to the observed object.

A typical objektiiv consists of multiple glass or plastic elements arranged to control focal length, aperture, field of view, and aberrations. Key specifications include focal length (determining magnification and angle of view), maximum aperture (expressed as an f-number, affecting light-gathering and depth of field), and optical design features that influence sharpness, contrast, distortion, and chromatic aberration. Modern objektiivid often incorporate coatings to reduce flare and improve transmission, as well as aspherical or low-dispersion elements to correct aberrations.

Common types include prime lenses (fixed focal length), zoom lenses (variable focal length), wide-angle, standard, telephoto, and macro objektiivid. Additional features may include autofocus motors, optical or sensor-shift image stabilization, and electronic communication with camera bodies via lens mounts and contacts.

Applications span consumer and professional photography, scientific microscopy, astronomy, and industrial imaging. Proper use and maintenance—cleaning elements, protecting coatings, and storing in controlled environments—help preserve optical performance. Limitations arise from physical trade-offs among size, weight, aperture, and optical complexity, as well as diffraction limits and residual aberrations.