In my opinion, the optimal "gallery size" providing professional resolution hinges directly on the native resolution of the lens (megapixels). The following is based on personal opinion: 8 MP = 11 x 14" | 6 MP = 8 x 10" | 5 MP = 6 x 8" | 4 MP = 5 x 7" | 3 MP = 5 x 7" | 2 MP = 4 x 6" | 1 MP = 2.5 x 3.5" The advantage gleaned from cameras with greater than 8 megapixels is largely elusive ;-)
Roger-in-FL