I have a 75mm 1.8 Olympus lens on loan from a friend, and on a whim, I also pulled out the old 70mm f2 Pen lens....Yikes.

It's fun to try new lenses. I've been walking around with the Olympus 75mm 1.8 lens on the front of an OMD EM-5 and I have to say that it's just wonderful. I shot an image wide open yesterday that made me really stop and look at the out of focus areas. But the killer stuff is the area of the image that is in focus. Very sharp and detailed. But after reading so many people praising this lens I really didn't expect much less. While I have the lens on loan from a VSL reader (Platinum Level) for the next two weeks my first, knee jerk, response was to think about pulling out the credit card and ordering one for myself.

I was half way to the computer to order when an odd thought stopped me. 'What about that old 70mm f2.0 Pen lens you have sitting in the cabinet with its peers? Wanna give that a side by side kind of thing?'

The last time I tried out the older 70mm was on an EP-3 and the EP-3 wasn't exactly a darling camera for the use of manual focus lenses. No focus peaking and the ability to magnify the frame seemed different than our current cameras; certainly less convenient. I'd tried it and gotten so-so results and the truth is that I probably missed focus more often than I nailed it. Since I was shooting nearly wide open a near miss is as good as a mile. After more than my share of fuzzy files it went back into a drawer. Until Monday.

I decided to give the 70mm a fair shake. I'd seen what the 75mm could do and I figured that there was no way 40 year old, half frame film technology would come close. I evened it up as well as I could. Off came the front filter. Then I spent half an hour carefully cleaning the lens. I found the Pen-f to M4:3 adapter that had the best track record for reliable performance and I was off. At f2.0 the lens was okay but by f2.8 it was right in line with modern lenses. At f4.0 it was difficult for me to see much difference between the 70mm and the 75mm. By f5.6 we were slicing electrons to see the difference.

While the 75mm modern lens is much more resistant to flare with light sources in the field of view the older, 70mm lens stood up quite well at most apertures. How well? Hmmm. Yesterday I had an assignment to shoot 4 executives (individually) in the same way that I'd shot a previous executive for the company a few months ago. They have an east facing conference room and we were shooting in the afternoon. The wall of windows facing east was like having a tremendous soft box at my disposal. The last image was available light so I tried matching up the same look and feel for yesterday's shoot.

When I left the house to go to the client's location I was hell bent on using the Nikon D7100 and the 85mm f1.8 G lens. It's sharp and methodical. But I tossed the black EM-5 and the 70mm Pen lens into the bag just so I'd have a fun play camera to use around the edges of the primary shoot. But when I got into the conference room and got my tripod set up, opened the blinds and measured the light I decided, "What the hell..." and pulled the Olympus combo out instead of the Nikon critical mass ensemble.

I locked the lens at f2.8, did a careful custom white balance, and proceeded to shoot all four of the executives with the same set up. What I was seeing on the rear screen was very nice. I took time to hit the image magnification often to double check critical focus. On the way home I had one of the "Oh my God, what was I thinking??!!" moments. My anxiety is never too far away and perhaps it's because I take chances instead of doing the logical and rational thing each day.

I brought the files into Lightroom and started looking around. I was impressed. Then I jumped into wholesale pixel peeping and I was more than a little shocked to find the files to be pretty much critically sharp right there at f2.8. I shot a few frames at the end with the 75mm 1.8 in exactly the same way and setting. f2.8 etc., same camera. And while the newer lens might be microscopically sharper it's not, "Oh Gosh! Let's drop another $900 for something we've already got covered."

Will the new lens out perform the old one? Probably in every single metric. Do I really care? Not as much as a might have in years past. If the eyes in the portrait are critically sharp and the expression is wonderful and expressive then I think we've hit the bullseye in most portrait set ups. Both lenses are great. I'm glad I gave the old one another chance. It now has a new leaf on life. Right now it's glued to the black EM5. The 17mm 1.8 Olympus is on the chrome body. I'm saving the Panasonic GH3 and GH4 for use with the zooms. All is right with the universe.

Thanks for all the great feedback on the new 75mm. When the 70mm gives up the ghost or gets run over by a horde of Austin bicyclists it's the one I'll buy as a replacement. In the mean time the A/B test continues.