I have both a Canonet QL17 GIII and a QL19 GIII and they are both great little cameras. The only real differences are the battery check display is in the viewfinder, the shutter cocked indicator is missing and the focal length of the lens is 45mm instead of the 40mm with the QL17 GIII. As "Filmgoerjuan" point out the lens is a 5 element lens instead of 6, and of course it's a 1.9 against a 1.7. the 19 is much rarer than the 17, and if you get a chance to buy a nice one you will not be disappointed. 😀