This is a 'flat' conversion of an Alpha 900 ISO 100 file using ACR 5.3. Contrast is set to -50 (no contrast added) and Brightness to 0 (using -50 Brightness is not an option, only small adjustments on the minus side are valid). 'Linear' contrast is used and all other controls are neutral. The exposure control is used to get the top of histogram correctly placed with only the very brightest (reflected, specular) highlights clipped (the edge of the guitar watch).

For the A900, a correction of -0.4 EV was needed to do this (the original camera exposure was effectively set manually, though A mode was used with +0.7 - it was set to match the Nikon D3X, both exposing their nominal ISO images for 1/2 sec at f/8).

The next image shows the Nikon D3X file treated in the same way, the main adjustment being a greater cut in exposure.