Olympus M.Zuiko Digital ED 40-150mm f4.0-5.6 R

The small lens with the big name...

I recently ordered a new lens for my Olympus Pen rig - the Olympus M.Zuiko Digital ED 40-150mm f4.0-5.6 R. While its name is big, this small lens is also proving to be a big bang for the buck. Here are my first impressions of this small and cheap ($150) lens for Micro four thirds...

small and cheap, in the palm of your hand

As you can see in the photo above, the Olympus M.Zuiko Digital ED 40-150mm f4.0-5.6 R is a small package offering an equivalent of an 80-300mm lens (the M43rds system is a half-frame sensor, so the crop factor is 2x making the 40-150 essentially an 80-300mm)

The body is plastic, the grips are plastic, the mount is, well, plastic. Basically, the lens elements (13 in all) and the digital circuitry are all that are not plastic. But at this price point, that's to be expected.

I've not run any real, scientific tests on this lens, and don't intend to. As I wasn't in the market for a $500-$600 pro-version of this lens, it is what it is.
And what is it? 
Its small at only 85mm long collapsed, 
cheap at only $150, 
lightweight, weighing in at 190 grams,
and slow - as its maximum aperture is only f/4 at 40mm, and a really slow 5.6 when zoomed out at 150mm.
But its also proving to be a very capable lens, with good to great sharpness in the centers, and only dropping down to acceptable sharpness at the edges. Its also a little low on contrast, but stopping down to f/8 seems to help with that a lot.
So this is NOT a low-light lens. For that, you'll have to spend more. Much more.
What this does allow me to do is get that extra reach needed for faraway compositions I can't easily get to otherwise.
Here are a few test photos made on a rainy day, from my old standby Duke Gardens at Duke University:

150mm@f/5.6
The drop off in focus looks good here, with an acceptable amount of sharpness and contrast

108mm@f/5.1
The Bokeh is surprisingly pleasing in this photo. Bokeh quality seems to come and go with this lens,
sometimes appearing dreamy, and sometimes looking very busy and unpleasing.

150mm@f/5.6
The bokeh (out of focus area) here looks very busy indeed.

150mm@f/8
This bloom was up in a tree about 30 feet away, and shows the reason for having this lens.
Stopped down to f/8 here, contrast has improved nicely.

66mm@f/8
Showing how the contrast improves nicely again at f/8

114mm@f/8
While this lens isn't razor sharp, it was sharp enough to resolve this tiny ant

Field of view at 40mm

Shot at 150mm from the same position

150mm@f/5.6
Again, the Bokeh here looks very smooth

40mm@f/8
This appears the sharpest overall combination, as both sharpness and contrast appear
to fall off a little as you zoom out from 40mm through 150mm

Parting thoughts: So, overall, I'm pretty happy with this lens. Its gives me capabilities I didn't have before with my little Olympus EPL2, and it was immediately apparent how nice it was to be able to zoom way in on subjects in order to isolate them. As you can see in the above samples, the depth of field can be quite shallow, even at f/5.6 and f/8, so its a good thing this lens was able to auto-focus both quickly and accurately most of the time (and it does offer manual focus, which works well too).
While I wish, like all my lenses, that this was a bit faster, say f/4 throughout its range if not f/2.8, I was unwilling to ante up the premium needed for a faster lens in this zoom range.
While its not razor sharp, and I'd like quite a bit more contrast, its at least as sharp as the kit 14-42 II that came with the camera if not a bit sharper, and its size and weight make it a great travel lens.
At this point I'd award it 3 out of 5 stars, with more weight given to value than to performance.