So what do we mean by distortion anyway?įirst of all, it's important to understand what we mean by distortion here.
CAN PICASA CORRECT CAMERA LENS DISTORTION SERIES
So what are the manufacturers playing at? Why are they releasing lenses with distortion, what effect does it have, and should dpreview review the distorted or the corrected output? We spoke to a series of leading camera and lens makers, as well as the creators of leading RAW converters to find out just what's going on.
CAN PICASA CORRECT CAMERA LENS DISTORTION SOFTWARE
With the arrival of Micro Four Thirds, we now have an interchangeable lens system with many lenses that require software correction of distortion. There's no reason to believe this is a particularly new approach for camera makers (it would help explain the sudden trend for including 28mm equivalent wide-angle zooms in compact cameras), but its appearance in enthusiast cameras such as the Panasonic DMC-LX3, which output RAW data, means it has become potentially visible to the end user. The advent of live view digital cameras (fixed and interchangeable lens) not only allows software correction of distortion (something impossible in an analog camera), but crucially also lets you see the result of whatever distortion corrections are being applied at the point of shooting, so the preview image matches the captured image. In the film era, distortion correction had to be designed into the imaging lens, and this was (and remains) true for digital SLRs too (the need for the captured image to match what the photographer saw through the viewfinder limits what the camera can do to the shot once taken). It's a process that has divided the forums, with some arguing passionately that it's cheating and that the lenses aren't really as good as they appear, while others maintain that it's the final results that matter, rather than how they're achieved.
What's more important, the final image or how it's achieved? Over the past year or so, we've encountered an increasing number of cameras with lenses that capture significantly distorted images which are then corrected using in-camera software. In-camera distortion correction: Can software ever take the place of optical excellence? Richard Butler looks at the trend towards cameras correcting lens distortion and what it means for photographers.