At first, the images look quiet similar. But the statements in the dpreview forum are pretty harsh:
- "SD1 looks sharper!"
- "Not only sharper. In Quatro I see a lot of color artefacts."
- "If the SD1 had live view and an EVF, it would be the better camera. Certainly it produces a better image."
- "Merrill was/is clearly outstanding!"
- "This just makes me think what sort of fabulous camera a mirrorless SD Merrill H would have been."
- "Once again the comparison show that 1:1:1 layers structure of the Foveon Merrill of the SD1 wins over the poor and rubbish 1:0.25:0.25 structure of the Quattro"
- "The SD1M will be my last Foveon camera unless Sigma resurrects the Merrill chip in an improved body."
While the Quattro in general seems to have an edge regarding luminance resolution, many people
seem to prefer the look of the Merrill generation.
So what is it?
Maybe these 200% crops help to understand:
(click images for full resolution)
Clearly visible how destructive the default luma-noise reduction setting works with Quattro files,
but then luma-NR off shows how noisy the Quattro is on pixel level.
So, finding the balance between noise reduction and adding/lowering sharpness is the tricky part with Quattro, while the Merrill sensor seems to be more forgiving and stable.