This is the last version prior to the Summilux Asph. Designed by Peter Karbe, it sort of transitions between ealier Mandler designs and the current Asph, which is also designed by Mr. Karbe.
It is a 7 element, 5 grouping design with a 12 blade aperture mechanism. This mechanism yields almost perfectly circular bokeh throughout the aperture range. You can expect half click stops between the aperture settings. It weighs in at 275g/9.7oz in black, and 380g/13.4oz in silver. Serial numbers began in the 3588960 and production continued up to serial number 4011798. The lens has a built in hood.
This lens is not the perfect 50mm that the current Asph represents. You can expect CA in out of focus areas and also with very high contrast situations. CA is very well controlled, and limited to less than 1 pixel generally. Out of focus chromatic aberration is the standard green/purple associated with almost all fast lenses, although it is significantly less visible in this lens compared to Zeiss or equivalent Japanes makes.
This lens can be had in the used market for around US$2400 – $3000 and it is readily available at the time of writing. There is also an E43 version, which is optically the same, but it only focuses to 1 meter vs 0.7 meter for the E46 version.
All testing done by Andrew Gough.