The Sigma SD1 Merrill utilizes the same Sigma/Foveon true-color sensor as found in the Sigma DP Merrill cameras.
This full aperture series comparison includes HD and UltraHD images from f/1.4 through f/16 along with analysis of performance and large crops. In DAP:
Sigma 35/1.4 vs Sigma 18-35mm f/1.8 (Creek Flows Through)
Also included is commentary on autfocus performance and camera operation.
Sigma SD1 Merrill + Sigma 18-35mm f/1.8
Sigma SD1 Merrill