Kiron made three versions of the 70-150mm zoom. A one touch f4 marketed under their own name. A one touch f3.8 marketed for Vivitar and this two touch zoom marketed for Vivitar. Tnis lens is the two touch version. Macro is not full time on this version and it is slighty larger than the one touch versions. Optics on all three versions are essentially the same. See my Kiron 70--150mm f4 review here. My copy of this lens has an FD mount. I am testing it on my Eos-M3. It is front heavy on the M3 which causes a bit of a problem since the M3 has a small hand grip. The lens aperture clicks at half stops. Focus throw is somewhat short but focusing is easy. It is sharp wide open at 70mm just like its Kiron brother. At 150mm f3.8 it is a little soft. It tightens up quickly and is very sharp at f8. Macro mode is not full time but it is easy to engage. Performance in macro range is similar to performance at 70mm. This is a very good macro lens for the budget minded photographer. Bokeh fringing is barely noticeable. The Kiron 70-150mm f4 fringes in high contrast lighting but this lens controls it well. It does have a built in hood. Contrast is excellent at all apertures and shadow detail is quite good. Bokeh is smooth at f3.8 w/ a bit of halo. At higher apertures the halo disappears but bokeh is still natural and smooth. I do suggest a tripod for those of you who do not have cameras with in-body stabization.