Sigma DP1 Dynamic Range

There has been quite a bit of discussion about the DP1 performance compared with other compact cameras. Much of it has been negative. Some have pointed out that the low ISO DP1 images upscaled to 12MP fail to capture noticeably more detail than those from the excellent Canon G9 viewed at native size. Others have pointed to the disappointing high ISO results demonstrated by in-camera JPEGs from the pre-production DP1 used in the Imaging Resource Comparometer. Personally, I have been most impressed with the tonal range I'm seeing in the image samples we've seen from capable photographers. Download Sigma Photo Pro (SPP), get Carl Rytterfalk's DP1 RAW pack, and play. If you use a Mac, get SPP 3.1 here. Carl might just be able to help out the PC users ;-).

Addendum: Carl has kindly allowed me to use his RAW files as examples. Image #6 of 10 (SDIM0408.X3F) in the RAW pack, the photo of shoes on a table, shows quite a bit of exposure latitude despite being shot at ISO 400. The following animated GIF demonstrates the highlight headroom. Watch as the highlight slider in SPP is adjusted. The GIF is just over 1MB in size, so it may take a bit to load depending on your connection. Also, please note that the apparent noise is actually due to posterization, which results from the conversion to a 256-color GIF.



2nd Addendum: It seems that the ISO 400 and 800 DP1 images have a shocking amount of highlight headroom during RAW processing, whereas the shadows are nothing special (in fact, an early impression is that they seem rather blocked up). Click here for an example of the highlight latitude. The likely explanation for this is that the high ISO files actually represent "pushed" underexposed low ISO files. This would explain how the highlights are restorable with negative EV in post, which would act to simply reverse the push. I'd like to see an evaluation of the DP1 dynamic range at the base ISO.