Chuck A
The simplest thing to do is ignore it, it should not get worse, it is pretty typical of Su and EGe lens, after ten years.
The simplest process is to buy
- set of watchmakers screw drivers
- cotton waste sticks
- can of Zippo lighter fluid
- PTFE liquid applicator (Tandy's)
- ladies nail varnish
- deep tray 8x10" photo tray or tea tray
- 3" pressure sensitive tape
Matt Denton recommends a full strip but it is easier to only remove the rear ring, this only needs undoing the three screws, and then only remove some of the grease.
First place the lens in a deep tray, because the screws are small and dont need to be dropped unto the lounge deep pile carpet. Then remove the paint sealing the three screws which secure the lens register ring to the lens, pick off the paint with the smallest screw driver. Then remove the three screws stick them to the pressure sensitive tape, and then remove the ring and run the lens out to mimium focus distance. Matts site has nice photographs of the ring to remove.
This provides enough access to the helicod to remove some fraction of the congealed grease, by wetting the cotton waste stick with Zippo fluid and wiping off any accessible grease with the stick. Use lots of sticks until the exposed helicod is clean, dont let any fluid penetrate, there is no reson to risk Zippo fluid ingress, into the lens. Also remove any grease from the lens register ring.
When the helicod is clean apply a two or three drips to each helicod thread at the innermost end of the threads you can reach with the PTFE applicator, you could try one drop per thread to start. Then work the lens focus back to infinity and out to close focus five times, the near focus stop should still stop the lens unscrewing past closest focus. This should clear the tight spot! the PTFE will work inwards and mix with the hardened grease, that you cannot reach.
If it does not clear the tight spot - reclean the exposed helicod thread with Zippo on cotton waste sticks as before and repeat to five times back and forward step.
If the tight spot vanishes still remove any grease which may have worked out of the helicod and dont apply any more PTFE.
Then replace the lens register ring, the screws recess should face out, to allow the screw heads to be recessed, then replace the three screws which secire the ring. They are not auto lug nuts and do not need to be tight merely snug, then seal the screws from working lose with nail varnish, if the ring has been cleaned with Zippo the nail varnish should adhere. It only needs a dab of varnish between the screw and the ring to stop the screws from coming undone.
This is a simpler process than Matt recommends but should still work.
Your lens should really perform you should not see its limits even with a slow B&W or slow slide film on a sturdy tripod.
I'd live with the tight spot, and only if it really impedes your photography bother with the PTFE and Zippo. The PTFE liquid wont migrate like mineral oil and ia a good long term cure. If you really like the lens then Matts process is the professional way but I'd not bother myself.
Noel
