Leica 90mm f2 APO ASPH (E55) Lens Overview

Virtually unmatched
Apochromatic color correction and an aspherical lens surface are combined for the first time in this lens of this type. Of its five individual elements, two are made of high-refraction glass, while two others feature anomalous partial dispersion. Its brilliance and quality of resolution are exemplary even at full aperture. Light falloff is very low. Its fast aperture for a 90mm lens lets you shoot at relatively short exposure times even in dim light, helping to minimize the effects of camera shake, as when photographing street scenes from a distance.

Angle of view (diagonal, horizontal, vertical)
27°, 23°, 15°

Optical design
Number of elements / groups: 5 / 5
Focal length: 90.9 mm
Entrance pupil: 58.6 mm (related to the first lens surface in light direction)
Focusing range: 1 m to Infinity

Distance setting
Scale: combined meter/feet-increments
Smallest object field: 220 mm x 330 mm        
Highest reproduction ratio: 1:9

Diaphragm
Setting / Type: with clickstops (including half values), manual diaphragm
Smallest aperture: f/16

Bayonet
Leica M quick-change bayonet

Filter (type)
internal thread for screw-in type filters E 55

Lens hood
built-in, telescopic

Dimensions and weight
Length: 78 mm
Largest diameter: 64 mm
Weight: approx. 500 g