Supplementary lens that reduces minimum focus distance, available in +0.5 to +10 diopters. A +1 diopter lens halves the lens's focusing distance.
Technical Details
Close-up lenses are offered in diopter strengths from +0.5 to +10, with +1, +2, +4, and +10 diopters being the standard values. A +1 diopter lens, for example, halves the focusing distance of a 50mm lens from 45cm to 22.5cm. The lenses consist of single or multi-element systems, with achromatic doublets reducing chromatic aberration. Filter diameters range from 37mm to 127mm. Combinations of multiple close-up lenses add their diopter values but disproportionately amplify aberrations.
History & Development
Close-up lenses emerged in the 1920s alongside the development of 35mm film. Leitz introduced the first standardized close-up lenses for Leica lenses in 1930. Kodak established the diopter system for film cameras in 1935. In the 1960s, Canon and Nikon developed achromatic close-up lenses for professional film productions. Tiffen and Schneider-Kreuznach shaped the standards for broadcast and cinema cameras from the 1970s onwards. Today, digital macro lenses dominate the market, but close-up lenses remain relevant for specialized applications.
Practical Use in Film
Douglas Trumbull used +4 diopter lenses on Zeiss lenses for extreme close-ups of the HAL 9000 camera in "2001: A Space Odyssey" (1968). Ridley Scott employed close-up lenses for detailed shots of the Alien creature to maximize available depth of field. In documentaries, +1 or +2 diopters allow for spontaneous macro shots without changing lenses. Close-up lenses noticeably reduce depth of field and can cause edge softness (vignetting), especially with wide-angle lenses under 35mm focal length.
Comparison & Alternatives
Macro lenses offer higher optical quality but require lens changes and cost 10-20 times more. Extension tubes mechanically increase the flange distance but reduce the light intensity by 1-3 stops. Bellows devices allow for stepless magnification but are unsuitable for handheld shots. Close-up lenses remain the fastest solution for moderate close-ups without light loss, while macro lenses are essential for the highest quality demands and magnifications beyond 1:2.