Olympus E-PM1: Performance

PERFORMANCE
As a third generation PEN digital, the PM1 stands to inherit all that Olympus has learned through refinements to the earlier cameras as well as the inexorable march forward of technology. Let's see what the PEN offers in its third time at bat.

Shooting Performance
One thing the PM1 has not inherited is a DSLR-class start up time. The camera takes about 2.25 seconds to display the shooting screen, with a first shot coming around 2.6 seconds. Single shot to shot times with a 95 MB/second SDHC memory card ran about 1 second, chiefly because the PM1 monitor has a short blackout period after each shot.

The PM1 captured 11 fine quality, large JPEG files in 2 seconds at its continuous high-speed shooting mode of 5.5 fps before the buffer slowed. Write time for those 11 shots with the 95 MB/sec card was about 3.5 seconds. Make image quality a RAW/JPEG combo and you get 8 shots in continuous high-speed with about a 9 second write time.

Swap the 95 MB card for a 45MB/sec model and the camera manages 10 JPEG shots before things slow. Write time for the 10 shots is also about 3.5 seconds. Finally, a class 10 30MB/sec card produced eight JPEG shots before the buffer slowed, and also took about 3.5 seconds to write. Clearly, the PM1 benefits from faster memory media to a degree, but individual users will have to determine if the incremental gains are worth the added expense for that fast card. If you don't habitually shoot continuous high-speed captures, you might be perfectly happy with the money saving class 10 or slower card. The 5.5 fps continuous shooting rate is predicated upon image stabilization being switched off. With stabilization enabled the camera manages about 4 fps.

When to stabilize? Before the advent of stabilization the rough rule of thumb for hand holding a camera was to set a shutter speed that was the inverse of the camera lens's focal length - a 50mm lens would be 1/50th of a second, for example. With the field of view provided by the 50mm lens, the 1/50th of a second shutter would be quick enough to cancel camera shake induced by the user, assuming the user had a reasonably stable hold. In the case of the PM1 with its 14-42 zoom lens and 2x crop factor, we are looking at a focal range from 28-84 mm and so with a reasonably steady hold should be able to produce an image free from camera shake by pairing the actual focal length with a shutter speed in the 1/30th to 1/90th of a second range. If you're unable to generate a shutter speed to complement the focal length you're shooting at then it might be time to enable stabilization.

Shutter Lag (press-to-capture, pre-focused)

AF Acquisition (press-to-capture, no pre-focus)

Continuous Shooting

*Note: Continuous shooting framerates are based on the camera's fastest full-resolution JPEG continuous shooting mode, using the fastest media type available (300x CF, SDHC, etc.). "Frames" notes the number of captures recorded per burst before the camera stops/slows to clear the buffer.

Shutter lag on the PM1 is a quick 0.01 seconds and AF acquisition time was nicely speedy 0.19 seconds. AF acquisition predictably slowed up a bit in dimmer light. There is a focus assist lamp.

The external flash provided with the PM1 has a guide number of 10 meters (32.8 feet) at 200 ISO, which translates into a flash range of about 9.3 feet at wide-angle and about 5.85 feet at telephoto with the 14-42mm lens used for this review. The guide number is about average for this class of camera, and not overly powerful, but the flash range increases as ISO levels rise and as we'll see later the PM1 can tolerate higher ISO levels without extracting too harsh a penalty in terms of noise. Flash recycle times ran anywhere from about 3.5 seconds to almost 7 seconds depending on the nature of the flash discharge.

As this review is being written the Olympus website has still not published a battery life expectancy for the PM1. The E-PL3 is listed with a 300 shot life expectancy and the PM1 uses the identical battery, so one would expect a similar performance. Carry at least one spare for all day shooting sessions just to be safe.

Lens Performance
The M.Zuiko Digital zoom that came with the PM1 turned in a pretty good performance optically - there was just the faintest hint of barrel distortion at wide-angle and an even slighter amount of pincushion distortion at telephoto. The lens was quite uniformly sharp at both wide-angle and telephoto with perhaps just a hint of softness in the corners. There was chromic aberration (purple fringing) present in some shots with high contrast boundary areas at wide-angle and in the worst cases the effect was noticeable at 200% enlargement. The telephoto end of the lens demonstrated little if any problems in this regard.