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Studio Tests
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If it does not load, please ensure you have flash player version 9 (or later) installed. The 14-150mm puts in a fairly typical performance for a superzoom in our studio tests. It's at its weakest at the extremes of the zoom, but in the middle of the range it does very well indeed. As usual on Micro Four Thirds, distortion is low due to being corrected in automatically software. Overall the lens's characteristics are remarkably similar to the Panasonic Lumix G Vario HD 14-140mm F4-5.6; indeed the only readily noticeable difference is likely to be lack of colour fringing when using the Panasonic lens on a Panasonic body (due to software correction of lateral CA). Wideangle performance is a little weak, though, compared to either the Olympus or Panasonic Micro Four Thirds kit lenses.
Macro Focus
Software correction of lens aberrationsA fundamental component of the Micro Four Thirds system design is the use of software to correct certain lens aberrations, most notably geometric distortion. For most users this is completely transparent - the camera corrects both the viewfinder image 'on the fly' and the JPEG files it records. Also, the relevant correction parameters are encoded directly into the raw files, which means that both the software supplied with the camera and industry-standard alternatives (including Adobe Camera Raw and Capture One) will convert them correctly. However users who like to experiment with more obscure raw developers that are unable to apply the requisite corrections will find themselves with distorted images, especially when shooting at the widest angles. Geometric DistortionThe graphic below shows just how much distortion you can expect to see when working with an unsupported converter. There's severe barrel distortion at wideangle, but by the time we zoom to the next marked focal length of 25mm it's neutralised, and beyond this there's just very mild pincushion distortion (this is a broadly similar approach to that adopted by the Panasonic 14-140mm). Clearly images shot at the widest settings will require correction in almost all cases - not only to render straight lines correctly, but also to match the original viewfinder composition.
Specific image quality issuesAs always, our studio tests are backed up by taking hundreds of photographs with the lens across a range of subjects, and examining them in detail. This allows us to confirm our studio observations, and identify any other issues which don't show up in the tests. FlareThe 14-150mm is generally pretty good at dealing with flare, and we saw few problems even when shooting in bright light without the hood. Pointing the camera directly into the sun at wideangle is tolerated pretty well - there's some local loss of contrast, but relatively little in the way of diagonal flare spot patterns. Shooting at the long end of the zoom in strongly backlit conditions (such that the sun is impinging directly on the front element), there's some loss of contrast but nothing fatal.
Background blur ('bokeh')One genuinely desirable, but difficult to measure aspect of a lens's performance is the ability to deliver smoothly blurred out-of-focus regions when trying to isolate a subject from the background, generally when using a long focal length and large aperture. While the 14-150mm by its very nature can't deliver quite as blurred backgrounds as superzooms for larger sensor systems, it makes up for this by providing renditions which are generally very pleasing, with smooth transitions to out-of-focus regions.
Chromatic aberration and corner softnessOur studio tests show that the 14-150mm suffers from pretty high lateral chromatic aberration at each end of the zoom range, which results in colour fringing towards the corners of the frame. On top of this, the corners are a lot less sharp than the center at wideangle. The examples below give an illustration of how this will affect real-world images. At 14mm we can see impressive detail resolution in the center, but the corner crop is soft with red/cyan fringing. The latter can, as usual, be corrected by many raw conversion programs - we've used our standard processor, Adobe Camera Raw (v5.7) with 'Fix Red/Cyan Fringe' set to -40 - but the corner softness remains.
At the long end of the zoom the pattern is similar - the center isn't quite as sharp as at 14mm, but again the corners are noticeably soft with red/cyan fringing. In this case the CA can be corrected in ACR 5.7 with 'Fix Red/Cyan Fringe' set to +40.
Flash shadowingNot specifically an image quality issue of the lens itself, but certainly one in combination with the camera body, is shadowing of the built-in flash at wideangle. Here the petite forms of the Micro Four Thirds cameras bring something of a disadvantage - the flashes don't lift all that far clear of the lens axis. The 14-150mm therefore gives noticeable shading on all Micro Four Thirds bodies to date. Below we show the extent of the problem, shooting a blank wall from about 2 meters. The lens casts a shadow on the lower right of the frame when used on the Olympus E-PL1; you have to zoom to 22mm to make this disappear completely (similar results are seen using the Panasonic GF1). Things are better on Panasonic's SLR-style bodies such as the G1 - there's a touch of shadowing at the bottom of the frame, but in this case it goes away at 18mm.
This is by no means unique to Micro Four Thirds; in fact it's not uncommon for smaller entry-level DSLRs to show similar problems with superzooms. But it's certainly worth knowing about, and perhaps keeping your 14-4x mm kit zoom for indoor flash work. Camera shake / image stabilization issuesDuring the course of this review we've taken hundreds of shots across a wide range of focal lengths and shutter speeds using both the E-P2 and E-PL1, and one thing that's stood out on examining them in detail is a far higher proportion of images blurred due to camera shake than we'd expect compared to shooting with a DSLR and superzoom lens. This is particularly the case at longer focal lengths (beyond 70mm or so) and slightly marginal shutter speeds of around 1/focal length (i.e. about a stop slower than we might expect to hand hold on Micro Four Thirds, according to the traditional rule of thumb). The reason for this isn't entirely clear, but it's probably a combination of factors. The 'rangefinder style' Pen bodies require the camera to be held out in front of you when using the rear LCD for framing, in a fashion that is clearly less stable than the conventional SLR 'eye to the viewfinder' pose. We frequently saw images which showed doubling along the short edge of the frame, corresponding to camera movement in the direction of pressure on the shutter button. So it seems likely that the IS system simply struggles to deal with the inevitable camera movement triggered by a press on the shutter release, which ends up being larger in amplitude relative to an SLR due to the less stable holding position (no matter how carefully you hold the camera and press the button). As this is more a camera and technique (rather than lens) related issue, we're not going to test it in great detail here, but do think it's worth pointing out for potential purchasers. It's also definitely worth thinking about your hand-holding technique perhaps more than usual when using this lens - for example making a habit of finding a wall or table on which to rest your elbows, whenever shutter speeds are dropping too low. Below are two typical examples illustrating the phenomenon so you can see what we're talking about, shot using IS mode 1 (with the latest firmware versions at the time of testing: E-PL1 v1.1, E-P2 v1.1, 14-150mm v1.0).
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