-Zuiko Om 28mm f/2.8
http://www.slrlensreview.com/web/olympus-slr-lenses-50/wide-angle-slr-lenses-86/390-olympus-om-zuiko-28mm-f28-lens-review.html
-Zuiko Om 28mm f/3.5
http://www.slrlensreview.com/web/olympus-slr-lenses-50/wide-angle-slr-lenses-86/388-olympus-om-zuiko-28mm-f35-lens-review.html
http://www.slrlensreview.com/web/olympus-slr-lenses-50/wide-angle-slr-lenses-86/390-olympus-om-zuiko-28mm-f28-lens-review.html
-Zuiko Om 28mm f/3.5
http://www.slrlensreview.com/web/olympus-slr-lenses-50/wide-angle-slr-lenses-86/388-olympus-om-zuiko-28mm-f35-lens-review.html