The Panasonic Lumix DMC-GX8 may be the first Micro Four Thirds camera to sport a 20.3-million-pixel sensor, but it has a whole host of other updates too. Andy Westlake takes it for a spin
Panasonic Lumix DMX-GX8 review: Performance
At one time, CSCs lagged well behind DSLRs when it came to speed. That era is long gone, and the GX8 is an extremely snappy performer. Using a high-speed Panasonic 16GB SDHC U3 card with the camera set to continuous high mode (and therefore with focus and exposure fixed), I got it to shoot at 8.1fps, rattling off 30 frames in raw+JPEG before the buffer was full, or almost 150 in JPEG-only mode. Switching the speed down a notch to 5.5fps allows autofocus, exposure adjustment and live view between frames. In this mode, the GX8 still shot 30 frames with raw enabled before slowing down, and almost 300 JPEG-only, which should be enough for the most committed ‘spray-and-pray’ practitioner. Switch to the electronic, rather than mechanical shutter and the camera can go faster still, up to 10fps, but with a risk of image distortion from rolling-shutter effects.
For photographers who like to shoot even quicker, Panasonic has included its 4K Photo mode. This uses high-resolution video technology to allow shooting at 30fps, but because this is presented as a drive mode rather than video, it encourages photographers to select shutter speeds appropriate for stills rather than video. It records MP4 files, and Panasonic provides an excellent interface for stepping through the individual frames and saving the ones you want as 8MP stills.
Three shooting modes are on offer: ‘4K Burst’ mode records so long as you hold down the shutter button, while ‘S/S’ mode behaves more like video, initiating recording on the first press of the shutter and ending on the second. Finally, there’s a very clever ‘Pre-Burst’ mode that continuously buffers the sensor’s output, and records from 1sec before the shutter button is pressed to 1sec afterwards. This is great for capturing peak action, but the downside is a significant impact on battery life.
Autofocus is, likewise, extremely impressive. Aided by Panasonic’s unique Depth from Defocus (DFD) technology that uses a knowledge of the optical characteristics of the lens to determine which way to move the focus group, it’s extremely swift in acquiring focus and with static subjects, unerringly accurate. The focus area can be set anywhere within the frame, and to almost any size to match your subject. Naturally, face detection is available, complete with eye detection to ensure optimal focus for portraits.
When it comes to JPEG image quality, the GX8 gives perfectly competent output with lots of fine detail, although its colour rendition isn’t as attractive as the Olympus E-M5 II’s. In part, this is due to auto white balance that errs distinctly towards the cool side, but also to a rather uninspiring standard colour mode that perhaps tries too hard to be accurate, rather than pleasant. At high ISO sensitivities the processing does a good job of maintaining strong colours, but the slightly over-enthusiastic noise reduction has a habit of obliterating low-contrast detail.