Excellent quality, but when you accolez map on the subject so that all the light sources is integrated in the determination of the white balance and you take your reference photo, it can happen (depending on the magnification ratio) that map even zoom in on the area occupied by the card, does not fully cover the area to be analyzed. Its small size can sometimes be problematic, but often an advantage because it takes up little space, so always present. The white balance measurements with the gray card is remarkable, the colors of my pictures are now true, I do not separate myself more and this limits retouching in post production.