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06-13-2008, 07:16 PM   #1
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Dismantling an AF lens

Has anyone had an AF lens apart - F, FA, DA (or 3rd party)? Pictures of the event possibly? I'm just curious of the inner workings of the aperture linkages and ae contacts and electronics and AF mechanisms. If someone has done this it may save me getting a cheap one and taking it apart myself . Notice I said "may"...

06-13-2008, 07:25 PM   #2
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You may be able to find a pdf of a repair manual schematic. That should give you some very good insight into the mechanisms & their relationships.
06-13-2008, 09:41 PM   #3
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yeah, just do it yourself. Just be sure to find a lens you won't want to use again. Among other things, the 'sensor' for focal length/focusing (for a zoom lens) is a very flimsy system of gold feelers that slide across a circuit board with gold contacts running the length of the board. not all of them run the full length- ok, so lets say there are four contacts, we'll call them 1, 2, 3, and 4. when the gold fingers are in contact with the contacts, the microprocessor registers a '1' or 'on.' let's say on a 28-80, when zoomed completely out (28mm) all the contacts are in contact, so all 4 signals registering a '1' equals 28mm. you zoom out and get to 35mm, and suddenly the top contact stops. So, contacts 1-3 returning a '1' equals 35mm. contacts 1-2 equals 50, and just contact 1 equals 80mm. It'll make a lot more sense once you open it up.

I guess the reason for that tangent is to say those fingers are incredibly delicate, and I doubt you'd be able to put the lens back together without damaging them the first time. I've got bags of three lenses (or the parts thereof) buried in my room somehwere. Two were broken already, but one was still in good condition- a FAJ 28-80. I wish I hadn't destroyed that lens, if only so that I could find out just how good/bad it really is.

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