The first medical Nikkor (200mm) lens was introduced in November, 1962. There were two known subsequent updates of this 200 which occurred in 1972 with some refinements in lens features, handling and improved power supplies and 1974 with cosmetic changes and improved lens coating. A radical change to the design of this lens series occurred in December, 1981 at whick time Nikon introduced a new version with a more practical focal length of 120mm and incorporating an Internal Focus (IF) design. The lens also had a faster maximum lens speed of f/4.0 and automatic flash exposure control capability with more modern bodies. This 120mm close-up Medical Nikkor (with special accessory lens for extreme close up work) provided a new dimension in precision, handling and user friendliness. Originally designed for medical research and close up work of the buccal cavity eyes etc., this specialized lens was also widely used for industrial, scientific research and even as a superb close-up lens for macrophotography. The main technical highlights of this lens was are an ability to record fine details in infinitely variable reproduction ratios from 1:11 to 1:1 life-size reproduction with shadowless illumination provided by a built-in ringlight at the front of the lens and all aided and abetted by a modelling light. With the accompanying a 2X close-up attachment lens (filter attachment size: 49mm), the maximum magnification ratio of 1X at 0.35m (lens only) can reach at an astonishing 2:1(2X) at its closest focusing distance (0.26m with 2X auxiliary lens attached). The internal focusing (IF) design used in its optical design provides two distinctive advantages; first, since there is no helical extension movement causing physical extension of the lens barrel during focusing the lens provides an excellent level of operational ease in the areas of lens handling; next, the IF design also enables the lens design to be very compact in its size and offer a silky smooth focusing action.
The choice of focal length at 120mm over the early version of 200mm of this lens is attributed to a few factors: a) the lens provides a faster maximum aperture at f/4.0 versus bulkiness of a possible 200mm with similar configuration, b) this lens was/is generally used for handheld photography where a longer focal length is more susceptible to the negative effects of hand-shake. The lens picture angle of 18° 50′ still provides reasonably natural perspective without too much of distortion when shooting at its closest focusing/working range. Its optical construction features a design of 9 elements in 6 groups.
The use of Nikon’s multicoating provides the lens with excellent colour fidelity and high image contrast across its entire aperture and focusing ranges. The exceptional flatness of field attributed to the superior optical design of the lens also minimize any possible optical defects commonly found in close-up lenses. One important feature among the many that this Nikkor close-up lens provides is the highly practical built-in ring-flash which has contributed to its distinguished physical appearance. The ring flash used in the Medical Nikkor utilises advanced thyristor control and can provide automatic flash exposure. With the built-in ringlight flash, this Medical Nikkor lens provides an innovative guide-number (GN) system that automatically sets an appropriate aperture according to the subject distance is set on the focusing ring. The built-in ring flash, apart from providing a more assuring optical result in exposures, also offers shadowless illumination. There are film speed settings provided on the lens while a red LED ready-light sits at the on top of lens barrel acting as visual confirmation of flash charge status.
Naturally, the flash can be turned off when not needed. The appropriate reproduction ratio also appears inside the camera’s viewfinder in the lower right-hand corner of the frame as the lens is focused (it serves as an alternative flash ready-light) , and is imprinted on the film at the instant of exposure; the imprinting system can also be turned off when it is not needed.
Technical details are as follows:
DISTANCE SCALE: Graduated in meters from 1.6m to 0.35m (white numerals for use with lens only) and from 0.33m to 0.26m (orange numerals applicable when 2X close-up attachment lens is attached; sticker-type conversion scale for feet also provided.
FLASH ILLUMINATION: Via built-in electronic flash ringlight at front of lens provides wraparound, shadowless illumination, flash can be turned off when not needed.
FLASH OUTPUT POWER: Approx 60W.
FLASH DURATION: Approx. 1/500sec. at ASA/ISO 25; controlled by thyristors and series circuitry and varies with film speed setting.
READY LIGHT: Provided; red LED on top of lens barrel; reproduction ratio in the viewfinder also serves as ready-light.
DIAPHRAGM: Fully automatic; diaphragm linked to focusing ring, so that correct aperture for flash photography is set as the focusing ring is turned
EXPOSURE MEASUREMENT: With built-in ringlight flash: automatic; guide-number (GN) system automatically sets appropriate aperture as subject distance is set on the focusing ring. Without flash: via stop-down method; meter coupling shoe not provided.
REPRODUCTION RATIO: Continuously variable from 1/11X to 1X (lens only) and 0.8X to 2X (with 2X close-up attachment lens).
DATA IMPRINTING: Possible when using ringlight flash; reproduction ratios (1/11X to 2X) can be recorded in lower right hand corner of the film; non-data shooting also possible by leaving DATA button in “off” position.
FOCUSING LAMP (MODEL LIGHT): 12V lamp at front of lens provided to facilitate focusing in dim light; glows for 16sec. after finger is taken off LAMP button; automatically stops glowing when ring light fires or power source is turned off.
POWER SOURCE: AC Power Unit LA-2 or DC Battery Pack LD-2 (optional).
WEIGHT 890g (lens only).
DIMENSIONS: 98mm dia. x 150mm long (overall); 142mm extension from lens flange.
ATTACHMENT LENS SIZE: 49mm front screw-in; 2X close-up attachment lenses provided.
FRONT LENS CAP : Slip-on.