Image Quality
Panasonic Lumix DMC-GM5 Review – Image Quality
The GM5 gives very acceptable results from its four-thirds sensor. It records detail levels that are commensurate with its 16-million-pixel sensor, which should be plenty for prints up to A3+ (12x16in) in size. Its shutter always uses an electronic first curtain, which effectively eliminates any possibility of detail loss from shutter-induced vibrations.
Dynamic range is very respectable at low ISOs, and Panasonic’s iDynamic mode can help exploit this to the full, by pulling up shadow detail in JPEG processing without sacrificing the highlights. But DR drops substantially above ISO 1600, reflecting a lack of ability to distinguish shadow detail from noise at higher settings.
Noise is kept well under control at sensitivities up to ISO 800. It then visibly starts to increase; ISO 1600 should still be fine for many purposes, but ISO 3200 and 6400 should be used with caution. We’d generally recommend steering clear of the top two ISOs wherever possible.
Overall, it’s fair to say that the GM5 offers very impressive image quality for a camera this size, although it’s closely challenged by the latest breed of compact cameras, with their relatively large sensors and built-in fast zoom lenses.
Resolution
The GM5 resolved a maximum of around 2800 l/ph on our Applied Imaging test chart. Smooth blurring of fine detail beyond this point shows the sensor has a well-matched optical low-pass filter. Resolution drops gradually as the ISO is increased, to around 2600 l/ph at ISO 800, 2400 l/ph at ISO 1600, and 2200 l/ph at ISO ISO 25,600. These tests were shot at 26mm (52mm equivalent) and f/5.6 using the 12-32mm f/3.5-5.6 zoom that’s supplied with the camera – the optimum settings for this lens.
Dynamic range
The GM5’s sensor delivers very respectable results, which are a very close match for its fixed-lens cousin, the DMC-LX100. Our Applied Imaging test measures the peak dynamic range as a very respectable 12.6EV at ISO 100, and this holds up to a still-very-usable 9.7EV at ISO 1600. Beyond this the range, it falls quickly, indicating that shadow detail will become increasingly swamped by noise. The very low measurements at ISO 6400 and above indicate that these settings will offer distinctly low image quality.
Colour
This 3D graph compares the colour shift from the reference colour to the photographed chart: the higher the peak, the greater the shift from the original.
In the default JPEG setting, colours are rendered generally neutrally across the range. Saturation is somewhat increased overall, and there’s a slight emphasis on the the blues, which should make for stronger landscapes.
Colour settings can of be adjusted in the Photo Style menu, which includes options designed for portraits and scenery. It’s important to get keep an eye on the camera’s white balance while shooting JPEGs, to ensure the correct color balance.
Noise
The images above have a resolution of 300ppi, reflecting a high-resolution print. The GM5 gives clean, detailed images at its lowest ISO setting, and maintains almost the same quality up to ISO 800, although a little luminance noise becomes visible in the mid tones.
Noise and noise reduction has an increasing impact in image quality at higher sensitivities, with noticeable loss of shadow detail at ISO 3200. At ISO 6400, noise reduction is smearing away almost all fine detail, and the top two settings are best avoided.
Adobe Camera Raw was unable to open the GM5’s files at the time of writing, so we examined them in SilkyPix Developer Studio SE. This reinforced our findings from the camera’s JPEGs; decent quality is maintained to ISO 1600, but higher settings should be used with caution.
The grey-card images above are JPEG files shot with the GM5’s default noise reduction and colour settings applied. The images are presented at 300ppi to reflect the noise that would be experienced when printing.
The results show the GM5 has well-controlled noise up to ISO 1600. Noise becomes increasingly problematic at higher senstivities, and although ISO 6400 doesn’t look too bad here, ISO 12,800, and ISO 25,600 in particular, are visibly very noisy. However, there will always be situations where the extended settings will obtain shots not otherwise achievable.
