Image Stabilizer

The E-P1 has a smaller, simpler IS system than the one employed in its high-end DSLRs, such as a the E-30. Olympus claims a 4-stop advantage for this IS system (though our tests have never shown an improvement on that scale).

The stabilization test

Twenty hand-held shots were taken of a static scene, half of those with stabilization, half without, the shutter speed was decreased by a stop and repeated (from 1/125 sec to 1/5 sec). The lens used was the Olympus 50 mm F2 (producing a 100 mm equiv. FOV), the test chart was 2.0 m away from the camera. to exaggerate the effect of camera shake the camera was only supported with one hand.

The resulting 120 images were then inspected and given a blur score from zero to three where zero represented a very blurred image and three a sharp image with no noticeable blur (see crop examples below). Obviously the amount of blur which is acceptable will depend on your personal taste and the final image size (for instance a '2: Soft' will still look fine as a 4x6 print or in a web gallery). Example crops from these four blur scores can be seen below.

0: Very blurred	1: Blurred
2: Soft	3: Sharp

Results (50 mm lens, 100 mm equiv.)

Turning the IS on helps provide a similar number of stable images even when you slow the shutter speed by a fraction over two stops. This isn't the most brilliant performance we've ever seen, but it will help significantly increase the number of sharp, stable images you take home with you. And, because it's built into the camera, the E-P1 can stabilize any lens, whether it be a cheap second-hand OM or a treasured Zeiss.

IS Test Results	More Graphs
IS Off
IS On (Mode 1)

Image shake anomalies

It's been reported elsewhere that the E-P1 has an anomolous 'image blur' issue when used with the M. Zuiko Digital 14-42mm F3.5-5.6 lens. Photographs shot at shutter speeds of 1/160 sec or 1/125 sec and a focal length of 42mm with image stabilisation enabled are less sharp than might be expected, at least when using the simplistic (1/effective focal length) rule of thumb to predict the slowest shutter speed which should be usable without camera shake (which in this case gives 1/90 sec). We've looked into this, shooting extensively with the Olympus lens and its Panasonic counterpart using 1/160 sec shutter speed, and while we agree (at least in part) with the observations, our interpretation of the cause is rather different.

We do indeed see that images shot at the long end of the zoom and at 1/160 sec show a much higher propensity towards camera shake than we'd expect using 85-90mm equivalent zooms on SLRs. But we note this happens with both the Olympus and Panasonic lens, regardless of whether or not the E-P1's in-body image stabilization is turned on or off. We don't see a consistent effect though; sometimes shots are perfectly sharp, sometimes not. Lkewise sometimes the direction of blur is up/down; sometimes left/right.
This, we believe, is substantially a reflection of the much less stable shooting position (compared to SLRs) that is needed with the E-P1. When shooting with an SLR, the correct posture is with both elbows tucked in, and with a key stabilizing point of contact between the viewfinder eyecup and the eyebrow; with the E-P1 you have to hold the camera out in front of you, with the screen at a comfortable distance for composition, making shake much more likely. And this being a relatively light, compact-like design there's a further temptation to hold the camera out at arm's length and shoot one-handed - which we found to be a recipe for image blur almost every time.

Of course we'd expect the E-P1's built-in image stabilization to make a substantial difference, but it doesn't; in fact we see no systematic effect whatsoever, either positive or negative. This simply points us to the conclusion that it's effectively not working at this shutter speed/focal length combination (we're wondering whether the camera's firmware simply decides not to operate the IS at what it considers to be 'fast' shutter speeds). The Panasonic lens's optical image stabilization seems do rather better, but it's still not perfect with a higher than expected proportion of unsharp shots - but again we think this is just a reflection of the relatively unstable shooting position.

We'll add to these preliminary findings if we are able to better characterise the issue.