I recently acquired (a gift) a 55mm Micro-Nikkor 3.5 ser #897XXX. I've accumulated a large number of things in another system and am quite naive about things Nikon..... While snooping around the net and eBay pictures, etc., I noticed that my lens has a pk-3 marking on it and the info I've found so far seems to be regarding the coupled extension that goes by this name. Is that extension only fully compatible with pk-3 lenses? Is there a definite range of bodies I should avoid for correctly functioning with this variation of this lens? I use hand-held metering and calculated macro settings, so I'll likely look for a cheap body without a working meter to play with this a bit. Sorry if this subject is a worn out one in here but I didn't readily find the answers to my questions just now. Thanks.