Hello, I have wondered what the difference in image quality would be between an old Olympus OM 50mm 1.4 lens and the highly regarded Olympus Zuiko Digital 4/3 50mm f2 macro lens. I took a walk around the house the other day with both lenses and took a series of photos with each lens at f2 and then took an additional with the OM lens at f1.4. The results can be seen on my photoshop page. These are straight from the camera and the file name lists the lens (ZD or OM and the f-stop. The comparison photos show full size crops (Left to right) of the ZD [email protected], the OM [email protected], and the [email protected] chrisfboyd's gallery | Photoshop.com I found that the older lens is very good. Of course my judgement is subjective but I think the old lens almost matches the sharpness of the new 4/3 lens and in some cases, I like the OM lens better. Overall, I give a slight edge to the Zuiko Digital 50mm, but you don't give up much in IQ using the old OM lens. Note, the OM lens and adapter go for about $130 while the ZD lens and adapter were over $400 (used). Other notes: The OM lens has a serial number over 1,000,000 and I found it to be noticeably sharper than older OM 50mm 1.4 lenses My other testing shows that this OM 50mm f1.4 lens is very similar in IQ to a canon FD(new) 50mm f1.4 lens that I had. I used the ZD lens in auotfocus mode (would not focus on bird so I used MF in that case) Direct comparisons all made at f2 All shot with E-PL2 with ISO set at 200, hand held. OM lens at f1.4 softer but very good. While I had the OM lens on, I took a quick photo of my daughter (OM 50 @f2) which I put into the portrait photo contest. https://www.mu-43.com/f48/july-2011-photo-contest-sponsored-nik-13793/index9.html My conclusion: The ZD 50mm macro is a great lens but you can do almost as well with an old OM 50mm lens.