ondrej_p.

<p><strong>WARNING</strong>: the information "this is only true for OM-1 and maybe OM-2, not the "N" versions or anything later" is incorrect. <strong>Some N versions indeed do have the foam.</strong> Recently a very high serial number OM-2N had the foam, but fortunately the prism was still intact.</p>

<p>The lens with "made in japan" engraved on the front around the front element indicates the last version of the lens. Just like the early production batches known as "silver nose" with bare metal on the front edge of the barrel. What is there to not understand ?</p> <p>w.r.t. the original post I think that it has a value for collector to display on shelf, but not for user. If I was buying a camera I would rather choose a slightly worn "user" than a shelf display piece. Foam degrades, grease separates and hardens, lubricants evaporate and cause fogging. Cameras were meant to be used. Unused cameras develop various stickyness syndromes (e.g. om-2 sticky second curtain magnet).</p>

<p>I also had a 65-200 with foggy element and just last night I managed to clean it. The most difficult part is getting to the foggy element, because it's the middle of 5 element group.<br> http://esif.world-traveller.org/om-sif/lensgroup/65-200mmf4.htm<br> However the group can be unscrewed from the back of the lens after removing the mount and aperture ring, and then carefully disassembled. Some elements are not distinctively convex or concave so be sure to put them back the correct way. The middle element is removable from the front.</p>

<p>The problem with Zuiko 65-200 is not degradation of cement - there is no cemented pair in the rear group of the lens. It is simple fogging and can be easily cleaned. Actually I have just done that.</p> <p>It is somewhat difficult to get to the fogged element: need to remove mount, then the thick chrome part and aperture ring. Then it is possible to unscrew the tube containing the whole rear group of 5 elements. The foggy one is in the middle, accessible from the front. The second and middle elements are easy to put back in the wrong orientation so before disassembly always put a mark on the outside surface, later clean with alcohol.</p>