My elderly neighbor came across his old camera gear today, and among the fray was the SMC Pentax 85-210mm f3.5 lens. The constant f3.5 on the barrel grabbed my attention, naturally, and the idea 420mm on a :43: body really got me thinking. A quick google search lead me to this info: K 85-210/3.5 Yup, it's apparently quite a rare gem. To collector's at least, having some pretty great optical properties and only being made for one year in 1976. So my question is, should i be considering making an offer to acquire this lens, and hopping on Amazon to buy an adapter to use it with my G3? Also, any particular make/type of adapter I should aim for? The weight of this lens is fairly immense, at over 1kg. I'd be using it for birding and wildlife in general. Obviously, using it for birds in flight would be quite a chore though. Leading me to final question, focusing. Does anybody have any experience with an old clunker like this gem, and trying to manual focus with the EVF while balancing, etc.? Any and all thoughts are welcome! P.S. It appears to be in incredible condition.