Nikon TC-20E III - Manual (Page 20)

En
20
With a prime lens
Focal length : Double that of a prime lens
Aperture
coupling range : f/2 - f/32
(effective aperture f/4 - f/64)
Reproduction
ratio : Double that of a prime lens
Depth of field : 1/2 that of a prime lens
Minimum
focusing distance : Same as that of a prime lens
Specifications and designs are subject to change without
notice or obligation on the part of the manufacturer.
■
Specifications
Lens construction : 7 elements in 5 groups (1 aspherical lens)
Diaphragm : Fully automatic
Exposure
measurement : Via full-aperture method with AI cameras or
cameras having a CPU; via stop-down method
for other cameras
Mount : Front: Special mount for AF-S/AF-I NIKKOR lens
Rear: Nikon bayonet mount
Dimensions : Approx. 66 mm (2.6 in.) dia. × 48 mm (1.9 in.)
extension from camera's lens mounting flange;
overall length is approx. 60 mm (2.4 in.)
Weight : Approx. 330 g (11.6 oz.)