Sharpness Fans, Your Ship Has Come In: Sigma dp2 Quattro Aperture Series 'Mosaic'
Get Sigma dp2 Quattro at B&H Photo.
This extremely demanding planar target tolerates no errors from a camera system or lens, mercilessly revealing every flaw, but the dp2 Quattro handles it with stunning sharpness and real depth of field hard to achieve in a DSLR.
In my ongoing review of the Sigma dp2 Quattro: