The Sigma DP1 Merrill has considerably more headroom in its X3F RAW files than the camera histogram or camera-generated JPEG would have you believe.
See my new exposure bracketing and ETTR for the Sigma DP1 Merrill page.
This page took quite a while to prepare (I felt rather drained when done), but I think it will be of benefit to any Sigma DP1 Merrill or DP2 Merrill user looking to get the most out of the camera. RAW (X3F) is certainly mandatory.
Is this shot “blown out”? Not with an X3F file. A good 4/3 stop of usable range is sitting right there ready to use.
For more on Expose To The Right (ETTR), see my pages in DAP.
Steve K writes:
Wow, you are really putting in the effort to figure out the DP1 Merrill, once again, what you do really helps all of us.
So I rented both the DP1M and DP2M for the weekend from lens rentals.com
In regards to your findings so far, Yes ETTR a must for sure, though which did you find more "accurate" to the bathroom scene, your pull plus minus contrast or pull plus fill light?
Also have you found anyway to make the color look more accurate to the scene. I'm referring to your D800 sample of the same image.
I.e making a custom WB? to bad SPP can't really adjust WB manually, or trying different picture control setting like neutral over standard, etc.
Lastly I was told to use SPP 5.31 for now to fix the export color profile issue but I think you loose the CA Correction.
DIGLLOYD: Lots of work having to deduce behavior that should be documented for customers, not made into a science fair project— but it is what is is!
The X3F variants I show are not accurate for any rendition— the JPEG is most accurate, but all have color accuracy issues compared to the Nikon D800E or Leica M9. For most accurate, I’d go with somewhat more contrast than the -1.0 version and a bit less of a pull.
It has always puzzled me that a vendor offers a camera JPEG option, but no single checkbox RAW conversion option of “output to match camera JPEG” (as a 16-bit TIF, with options to not pin the blacks or blow the highlights).
Custom white balance— all the conversions (Nikon and Leica in their respective comparisons) and the Sigma DP1M all used a custom white balance off the white sink. The problem seems to be that the Sigma sensor has color non-linearity across its tonal range, showing a particularly strong shift in the highlights (older Nikon DSLRs like the D2x used to have a mild form of this issue).
Since I am running version 5.3.2 of the Sigma Photo Pro software, a color space fix would have to be in a 5.3.3 or newer version which does not exist.
Because of the color issues and the ultra-high per-pixel resolution, I consider the Sigma DP1 to be a superb black and white camera. Although its resolution is a bit lower than the Leica MM, it is 1/8 the cost with far more versatile conversion options for black and white.