Surprises!

Arrived Minolta NEW MD 200/4 telephoto lens surprised me twice, very light weight 410 gr and the helicoid inner piece constructive material. Lighter weight comparing with 790 gr of MC TELE ROKKOR-QF 200/3,5 must have been brought by some engineering plastic optical construction, so I imagined at first, but a few seconds were not necessary to solve the weight question after disassembling of helicoid construction, yes, relatively long helicoid inner piece is made of engineering plastic, I was really surprised to have observed the fact. Because two pieces inner and outer helicoid pieces do not touch each other and just are floating on lubricant material while focusing procedure, engineering plastic material might be introduced so far as the problem of vulnerability of physical property. Most of mold forming areas are the surfaces between the a space for iris construction, so relatively easily it is removed, but a specific rear part of lens element constructed by heat pressing method prevented me from cleaning the surfaces at most rear part of the element.