This 35mm, giving a 50mm equivalent field in 24X36, is built lightweight (plastic bayonet) is ideal mat. No distortion, no AC even at full aperture, good reporting companion: AF is reactive (1/4 of total stroke turn) and low noise. It comes with caps without sun visor. The 49mm diameter allows to consider filters at lower costs. For an amateur like me, it is the standard fixed lens which usually remains on the case: It is really light and unobtrusive.