With the release of the new Sigma Photo Pro 6.5.0 Sigma made some changes in the noise reduction processing for Quattro cameras.
Sigma:
"It has an improved algorithm in noise reduction when developing RAW data for the sd Quattro series and dp Quattro series."
Let's see what has been changed:
click the image for full resolution
-No changes when NR is turned off. (first row)
-Middle position: SPP 6.5.0 adds a slightly higher amount of NR. (but no improvement in the NR quality)
-Bottom: Again very slightly more NR applied.
And now the SD1:
To keep it simple, i only show the best two versions.
Top: best default setting for this image
Bottom: overlay of a monochrome (blue channel) image over the color image.
click the image for full resolution
Conclusion:
-clearly better and cleaner rendering with less luminance noise on both SD1 samples.
(sharpness suffering a bit because of the mediocre edge performance of the 8-16mm lens)
Better ISO performance of the Quattro? Still a myth..