Overall image quality produced by the GH3 is very, very good. The 144-zone metering system copes admirably with tricky high-contrast scenes. The GH3 offers exposure compensation between -5EV and 5EV, however while out test shooting with our review sample we rarely had to use this feature, and even when we did we never had to dial in more than 0.7EV.
1/80sec @ f/14, ISO 125, 14mm
Using daylight-balanced lamps and a Datacolor Spyder Checkr chart we were able to ascertain how well the GH3 renders colour and white balance. Results between ISO 125 and 1600 were vibrant, punchy and rich in colour as might be expected. Better still, there was no sign of the saturation decreasing as we ramped up the sensitivity, at least until we reached ISO 25,600 where colours became slightly more muted compared to ISO 12,800.
1/4000sec @ f/8, ISO 6400, 128mm
Controlled resolution tests undertaken with our standard resolution test chart reveal that the GH3’s 16MP sensor is capable of rendering 32 lines per millimetre at ISO 100 when coupled with the 45mm f/2.8 Macro Leica D Vario-Elmarit lens. While this is certainly very impressive for a Micro Four Thirds sensor, APS-C sensors have scored slightly higher in the past. That’s not to take anything away from the GH3 though, which compared in isolation – or indeed against other cameras using MFT sensors – performs very well indeed.
Noise is very well controlled between ISO 125 and ISO 800, with the GH3 producing clean, finely detailed images, however some noise does begin to creep in at ISO 1600. At ISO 1600 and 3200 images are certainly usable, although if you plan on printing your images at 100% then be aware that noise may well be visible to the naked eye. Beyond ISO 6400 and noise starts to noticeably degrade image quality, with the top settings of so ISO 12,800 and 25,600 best avoided if possible, or at least used only in emergencies.
Comparing an unprocessed Raw file to a processed JPEG revealed a number of subtle differences. JPEG files tend to be slightly brighter in dark shadowed areas, whereas Raw files resolve more detail in the highlights. Side by side we also noticed that JPEG files have fractionally more contrast applied, while in-camera sharpening was clearly obvious in JPEG files.
As Panasonic’s flagship digital single lens mirrorless (DSLM) camera (more commonly referred to as a compact system camera) the Lumix GH3 has come on a long way from the two-year-old GH2 and brings with it a generous range of improvements. Indeed, with its larger hand grip, bigger battery, superb touchscreen and integrated Wi-Fi connectivity we don’t have any hesitation in saying the GH3 is one of the most intuitive CSCs we’ve used. It’s also well supported by a broad range of dedicated G-series lenses, with no fewer than 17 fixed focal lengths and zooms to choose from. Image quality is very good too, and while resolution of fine detail isn’t quite up there with the best APS-C equipped cameras, the GH3 nonetheless performs solidly enough to take on the DSLR competition with conviction.