The DP1 is provided with a CD-ROM containing the latest version of Sigma's Photo Pro (SPP) RAW converter. The software can also be downloaded from the Sigma DP1 website.
In our reviews we usually compare the supplied RAW conversion software, any optional manufacturer RAW conversion software and some third party RAW converter. In the DP1's case though there is not much choice at all. If you want to convert the camera's RAW files Sigma Photo Pro is your only option as third party converters such as Adobe Camera RAW, Silkypix or Capture One are not (yet) capable of reading DP1 RAW data.
JPEG - Large/Fine, Default settings
SPP - Sigma Photo Pro 2.5, Default settings
Place your mouse over the label below the image to see the color from a GretagMacbeth ColorChecker chart produced using each RAW converter. Sigma Photo Pro's default settings are similar - though by no means identical - to the JPEG output (they're actually slightly less contrasty and even less saturated), but you can of course tweak the settings to get the results you prefer. And you're going to want to.
Sharpness and Detail
Photo Pro with its default settings produces output that is very similar to an out-of-the-camera JPEG, although slightly sharper with a tad more contrast. Photo Pro in its 'Auto' mode (in which the software determines the optimal settings itself) provides the sharpest and 'punchiest' image. Considering the DP1's resolution there is an amazing amount of detail in this crop.
These crops demonstrate the DP1 can resolve a large amount of detail considering its resolution is not even 5 MP. There is even marginally more detail available from Sigma Photo Pro than can be obtained from out-of-the-camera JPEGs. Some will argue this is not 'real' detail (it is produced beyond Nyquist) but in any case it is useful as it improves the appearance of 'texture'.
The DP1 continues to deliver detail past Nyquist because the X3 sensor doesn't employ an anti-alias (low pass / blur) filter it. When shooting in RAW the camera provides an 'absolute resolution' of approximately 1550 LPH but there is 'some' detail visible far beyond this. This detail is not perfectly distinguishable but it will be visible as a broken texture and that is certainly better than the blurred area we would get from the anti-alias filter of a Bayer sensor camera.
JPEG from camera
Sigma Photo Pro
Photo Pro 2.5 is the latest release of Sigma's RAW converter and, as previous versions, allows for adjustment of Exposure, Contrast, Shadow, Highlight, Saturation, Sharpness
and Color. Sigma was amongst the very first ones to implement a 'Dynamic Range Enhancement' tool in its RAW converter when the X3 Fill Light function was integrated in Pro Photo 2.0. Of course this useful feature is included in the latest Pro Photo version as well.
Increasing X3 Fill Light raises the brightness of shadow areas
of the image and retrieves highlight detail, it appears to balance the
tone between highlight and shadow to extract maximum dynamic range. The
results are excellent and it would be almost impossible to squeeze similar results out of a JPEG image in a standard photo application. X3 Fill Light is controlled using a slider
(just like other parameters) and has an adjustment of -2 to +2 in 0.1