Andy Westlake tries out an unusual compact camera with a fixed ultra-wideangle lens in his Sigma dp0 Quattro review.
Sigma dp0 Quattro review – Resolution and dynamic range
The dp0’s resolution is hugely impressive at low ISO sensitivities, being close to 3,600l/ph, which is about as high as it could possibly record given its pixel count. In raw it gradually falls at higher ISOs, to about 2,400l/ph at ISO 6,400. But in JPEG it halves at ISO 1,600 to 1,800l/ph due a change in processing mode, then drops to about 1,600l/ph at ISO 6,400.
Our Applied Imaging dynamic range tests are designed for use with conventional sensors that use Bayer-pattern colour filter arrays, and we haven’t been able to extract sensible results from the dp0’s Foveon Quattro sensor. This means that we can’t present our usual dynamic range graph here.
In practice, however, the camera gives very acceptable dynamic range at low ISO settings. Sigma Photo Pro also makes it easy to get the most from the camera’s raw files, and routinely extracts noticeably more highlight detail than is recorded in the JPEGs without any user intervention at all. Sigma’s ‘X3 Fill Light’ slider does an excellent job of balancing highlight and shadow detail in converted files, and it’s possible to pull up a couple of extra detail in the shadows without the results looking over-processed.
At sensitivities of ISO 800 and above, though, there’s much less room to manoeuvre, as shadow regions become very noisy indeed.