The upper image has been shot a month after the lower one, but trying to reproduce the conditions. The top shot is the A100 with 50mm macro, ISO 200, AWB, AF, SSS, zero sharpening, zero NR, 1/200 at f5.6, processed from raw using ACR - settings (to duplicate the Mamiya shot below) +0.5 exposure and Brightness 64, Strong Contrast curve. To get the density right with +0.5 in ACR, -0.3 was needed in camera, maybe it should have been -0.6. The A100 metering gives more generous exposure to this subject than the Mamiya.

The lower image is on the Mamiya ZD with 80mm f2.8 lens, 1/250th at f5.6, ISO 200, all other conditions identical to the A100 (the parameters were set when processing the Mamiya file).

Both images were exported to the maximum 6144 pixel interpolated height of a vertical shot. This means the 100 per cent view represents a 75mb image from the A100, 85mb from the Mamiya. To match the pixel width of the image rather than the height, the Mamiya file was reduced to 4113 pixels from its original 4165. This gives the Mamiya a slight advantage. Also, the Mamiya framing is a little closer so the magnification is higher.

The focus plane may be slightly different too with the Mamiya sharper to the right side, the A100 to the left side as viewed. It was a matter of trying to catch some sunlight in about the same position, not easy in Scotland in February.

The Mamiya does not use an anti-aliasing filter, which gives its images a harder sharpness naturally. It also produces some coloured pixel artefacts from stone. You can make your own judgement as to how the Sony A100 compares with the Mamiya ZD (10 megapixel £400 DSLR verses 22 megapixel £8000 DSLR).