Panasonic’s Lumix DMC-LX100 combines a fast zoom lens and a four thirds sensor, in a stylish body with enthusiast-friendly controls and a built-in viewfinder. Andy Westlake finds out whether it lives up to its considerable promise
Panasonic Lumix DMC-LX100 Review – Image Quality
The Panasonic Lumix DMC-LX100’s four thirds sensor is unusually large for a camera with a built-in zoom lens, and this confers a distinct image quality advantage, especially at higher sensitivities. Image quality holds up very well to ISO 1600, with noise and noise reduction artefacts starting to become obviously visible at ISO 3200. Even ISO 6400 is quite usable, but the highest settings of ISO 12,800 and ISO 25,600 are essentially best used for emergencies only.
With its 12.8-million-pixel effective resolution, the LX100 records measurably less detail compared to cameras that use smaller 20-million-pixel, 1in-type sensors, such as the Canon PowerShot G7 X and the Sony Cyber-shot DSC-RX100 III. However, it’s still fully capable of making detailed A3+ (12 x 18in) prints. It offers less flexibility for cropping, though, which could be a concern given its short zoom.
The impressive dynamic range measurements of the LX100 match most interchangeable-lens cameras, and are slightly ahead of its competitors with 1in-type sensors. This means that overall the LX100 is right at the top of the class among fixed-zoom cameras. The ultra-fast lens helps make the most of the sensor’s capabilities, too.
The LX100 resolved a maximum of around 2800l/ph on our applied imaging test chart. Strong aliasing around the Nyquist frequency (the theoretical maximum the camera can resolve), along with false detail beyond it, suggest that the sensor has no optical low-pass filter. Resolution drops slowly as the ISO is increased, to around 2400l/ph at ISO 1600, 2200l/ph at ISO 12,800 and 2000 l/ph at ISO 25,600. This was tested at 60mm and f/4, which we found gave best results from the LX100’s lens.
Impressively for a fixed zoom compact, the LX100 gives an excellent dynamic range of 12.5EV at ISO 100. This holds up well to ISO 400, but then starts to drop, although ISO 1600 offers a still very acceptable 10EV. The very limited range at the top sensitivities, however, confirms their relatively poor image quality. Overall, though, this is slightly ahead of the LX100’s competitors, and Panasonic’s iDynamic function also helps users exploit this dynamic range to the full.
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 colour. In the default JPEG colour setting, colours are rendered evenly across the range, with some degree of emphasis on the greens and blues, which should be good for landscapes. Colour settings can be adjusted in the Photo Style menu, with modes tailored for such things as scenery and portraits.
The images above are printed at 300ppi, reflecting a full-resolution print size. The LX100 gives clean images up to about ISO 800, but at ISO 1600 luminance noise becomes clearly visible in its JPEG output. At higher sensitivities noise becomes increasingly visible and shadow detail blocks up, but ISO 3200 and ISO 6400 are still capable of giving acceptable results for non-critical purposes. The highest two ISOs are best avoided.
Adobe Camera Raw wasn’t capable of reading the LX100’s raw files, so we examined them using SilkyPix Developer Studio supplied with the camera. Colour noise starts to become visible in raw images at ISO 800, mainly in the shadows, and it becomes distinctly intrusive at ISO 6400. The top two ISOs are very noisy, underlining their status as emergency settings.
The grey-card images above are JPEG files shot with the LX100’s default noise reduction and colour settings applied. The 300ppi images are shown at 100% magnification to reflect the noise that would be experienced when printing.
The results show that the LX100 gives clean images at its lowest sensitivities, with luminance noise starting to show in the JPEGs at about ISO 1600. Luminance noise becomes increasingly pronounced as the ISO is raised further, and is pretty overwhelming at the top settings. In raw, colour noise starts to show up ISO 800, and again becomes very intense at the highest sensitivities.