Though its official base ISO starts at 125, the Sony RX100's ISO 80 images looked good printed at 24 x 36 inches. Color was muted, particularly yellows and greens, as we also found in our MacBeth test target.
ISO 125 shots also looked quite good at 24 x 36, with excellent detail, but the muted color persisted.
ISO 200 images also looked very good at 24 x 36, if a little softer than ISO 125. Not enough to require a smaller print size.
ISO 400 images printed very nicely at 20 x 30 inches, with sharp detail.
ISO 800 shots were soft enough at 20 x 30 that we preferred the 16 x 20-inch prints, though we'd still call the 20 x 30-inch prints usable for most subjects. By ISO 800, the red leaf swatch appeared soft.
ISO 1,600 shots are usable at 13 x 19 inches, but look better at a still fairly large 11 x 14 inch size. The red leaf swatch was somewhat soft at this point.
ISO 3,200 images look good at 8 x 10 inches, with the exception of the difficult red leaf swatch.
ISO 6,400 images are a bit soft for 8 x 10 inch prints, but look quite good at 5 x 7 inches.
Overall, the Sony RX100 stands out as a pocket camera that can produce good quality 24 x 36 inch prints from ISO 80 to 200, and even its highest ISO of 6,400 outputs a good quality 5 x 7. Impressive!