I got those lenses to fit in my underwater case for the XT10, it is small and light, and the price I paid is good, sure there is some trade-off, but I got the XF18\55 and the feeling is a different level, in the same range aperture and focal length, I can't see much of a difference between the 2, but I feel the difference in aperture because I use that lens underwater I was going to enjoying a closer focus distance