a 1:1 macro lens designed for full frame sensors but available in a number of mounts including Olympus Four Thirds dSLR system
the Four Thirds version has been discontinued
the Four Thirds version can be used on Micro Four Thirds system but the AF will be very slow as it is not CDAF optimised and phase AF is slow - you probably should regard it more like a manual focus lens
beautiful optics - sharp wide open, low distortion, nice bokeh but slow AF - slower than the Olympus ZD 50mm f/2.0 macro lens
on many cameras, many models appear to have front-focus AF error issues requiring microadjustment to give sharp AF images.
specs
150mm f/2.8
as with most macro lenses with internal focusing (IF), the lens looses between 1.5 to 2 f-stops in speed and the focal length reduces when set to the min. focus distance!
closest focus 38cm giving 1:1 macro and 7.6“ working distance
detachable tripod collar
barrel-type lens hood
72mm filter
AF-MF switch (when used with Four Thirds cameras this must be set to the same settings as the camera settings)
focus limiter: 0.38-0.52m; 0.52m-infinity; and full range
0.5EV vignetting wide open at infinity reducing to 0.17EV at 1:1 macro
sharpest at f/5.6 but very sharp wide open
minimal CA of 0.23px
BUT “the sample lens suffered from a rather extreme degree of decentering which pollutes the resolution potential of the lens (on the left image side) - a rather worrysome quality control issue.”