It took me a while to bring all the necessary pieces together but I finally have a "complete" ME-F example in my collection. The winder II was obtained during a camera swap to sweet'n a deal and the lens was purchased in mint condition at the same camera show a couple years ago. The guy really didn't know anything about it. I found it in its original box buried under junk in a bin. BTW... the box had a sticker with the original price of 550 bucks. Wow thats expensive. The lens only works with the ME-F body and thus sat on my shelf for the next year or so. The ME-F is difficult to find simply because it had horrible sales here in the US ( and in other markets ). I found 2 examples neither worked properly. A couple months ago, I found one out of Canada and jumped on the deal. Turned out to be a good find... great condition and still works. Pentax ME-F with ME II winder and the one and only 35-70mm f2.8 Autofocus lens. It was one of the first autofocus cameras ( maybe the first? ) to be marketed. Its slow. Its heavy. Reasons for its lack of success. The autofocus technology was built into an existing Pentax ME design which also made the AF feature somewhat of an add-on feel. From what I gather, it was also expensive. The setup you see here takes a total of 12 batteries!!!! 4 camera/watch batteries to run the internals, 4 AAA's to power the AF motor in the lens, and 4 AAs for the power winder. The glass itself is great and fast ( f2.8 ) for a zoom of that time. I used it on my other pentax K-mounts ( without the AF feature ) with nice results. The autofocus is activated by pressing one of two buttons on the top and side of the lens. Unlike the regular ME, the ME-F has focus assist lights in the viewfinder that looks like this "< * >". The green light in the middle will light up when focus is sensed. Focus sensor works with all K-mount lenses but it drives the AF lens when attached. Pentax had plans to release additional AF lenses compatible with the ME-F but abandoned those plans soon after. It wasn't until the legendary Minolta 7000 did AF really started to become popular. Despite its lack of success, the ME-F w/ 25-70mm f2.8 still has a special place in my display cabinet as being a significant example of pentax history. I like to think it showed Minolta and other companies that AF was just around the corner. BTW... The Minolta 7000 has a special place in my heart as well. It was my first serious SLR to learn. I stole it from my father for several years throughout college until I could afford my own. It already has a reserved spot in my cabinet when my father is done using it.