Image stabilization (IS Sync)
Olympus' hybrid image stabilization, which combines lens-based optical and camera-based sensor-shift algorithms, works really well. This was shot handheld at 1/10 second, which is about as slow as I can handhold even a lighter lens; if you have steady hands you could probably go even slower. It wasn't reliably good at that speed, though. At 1/13 second, however, I was able to get consistently shake-free results.
(1/13 sec, f4.5, ISO 200; raw processed for contrast, white balance and sharpness)
Sharpness
The lens is extremely sharp. On the next slide you can see a 100-percent crop of the focus area.
(1/400, f5, ISO 200)
Sharpness
This 100 percent crop from the previous photo gives you a sense of how sharp the lens is. Unfortunately, the images in our galleries are compressed and randomly scaled so it's actually a little sharper than it appears here. You need to view the full-size photo to really appreciate it.
Speed
Given how much glass it's moving and how narrow its angle of view is, the lens focuses pretty quickly. And you need to view it at full size to fully appreciate the sharpness -- check out the water droplets on the squirrel's muzzle.
(1/400 sec, f4, ISO 200)
Focus
I really wanted to see how it worked in the January 2016 blizzard here in NYC, and the answer is quite well. As you'd expect, close-to-whiteout conditions at times really baffled the autofocus system and I got more than my share of shots like this, but persistence and the focus-limiter helped as long as subjects weren't moving too quickly.
It didn't help that I tended to pull back on the manual-focus cuff without realizing it. And while manual focus is another option in these conditions, I had forgotten to change the camera's settings to a lower level of magnification for manual focus, essential when dealing with such a narrow angle of view (and manipulating the controls with gloves was too frustrating). Under normal conditions, however, the manual focus works quite well.
Weather sealing
The lens handled the cold and wet without any problems, and despite being a little lax about avoiding condensation formation (which happens when you head into a warm area after being out in the cold), it performed like a champ.
(1/400 sec, f4, EV+7, ISO 400; processed raw for contrast)
F5
The bare tree limbs in the background give you a sense of the out-of-focus-area characteristics of the lens.
(1/320 sec, f5, EV +1, ISO 400; raw processed for exposure and cropped to remove something annoying jutting into the bottom left of the frame)
Depth of field
Even though Micro Four Thirds cameras have more depth-of-field at a given aperture than those with larger sensors like APS-C and full-frame, f4 is still pretty shallow when you're at a 600mm-equivalent angle-of view. This shows the out-of-focus areas in front and behind the area of focus, and you can also see the nice round out-of-focus highlights.
(1/400 sec, f4, ISO 400)
F9
Nothing much to say about this, just an example shot at f9.
(1/640 sec, f9, ISO 400)
F22
At its narrowest aperture, the sharpness unsurprisingly softens a bit, but it's still pretty good.
(1/320 sec, f22, ISO 400)
Fringing
I was incredibly impressed with the lack of chromatic aberration in this lens. Frequently, companies will fix fringing algorithmically for the JPEGs but in the raw files you can see how bad it is. The raw files displayed practically none, even in shots like this where you really expect to see it. However, it bears noting that narrow angle lenses are less prone to it anyway.
(1/320 sec, f4, EV +1, ISO 400)
Textures
Texture reproduction is excellent. But mostly I just never noticed how creepy this statue looked before and felt like sharing.
(1/400 sec, f5.6, ISO 200)