Tri-Elmar-M 16-18-21mm f/4 Aspherical Manual Focus Lens (6-Bit, Updated for Digital)
Super Wide Angle Lens
The Leica Tri-Elmar-M 16-18-21mm f/4 Aspherical Lens is a clever and versatile wide angle lens for the Leica shooter who doesn't need the higher speed of single-focal-length lenses. The Tri-Elmar is not a zoom, but offers three focal lengths with 16mm, 18mm and 21mm. With minimal distortion and barely perceptible field curvature, it can be recommended for highly demanding architecture photography even at the 16mm setting.
Used on the digital M8, it produces the image effect of a 21 - 28 mm lens. It has been updated with "6-bit" coding, which allows the digital M camera to read this information optically and to identify which lens is being used. The camera can then (optionally) apply a "final stage" software-based vignetting correction (for RAW images the lens used is simply recorded, no change is made).