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135mm f4 not focusing in range finder


retcheto

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I just got a 135mm F4 off eBay. It’s in good condition and very clean, but when I mount it on my MP240 and focus, the rangefinder focus patch doesn’t move (my other lenses work fine). The lens does focus in LV

 

Is there an easy fix for this or should I send it back?

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To expand a bit on sydrxx's post, here is a view inside the back of a 135mm f/4 (Tele-Elmar). :

 

http://www.leicashop.com/media/catalog/product/cache/2/image/9df78eab33525d08d6e5fb8d27136e95/2/7/27313_12_d.jpg

 

If this looks like your lens in general shape (not counting knurling and condition), then - the prominent brass-and-black bar just inside the lens mount opening is what "drives" your RF patch to move it. It is driven towards the camera by the lens focus mechanism deep inside, and follows the lens motion away from the camera under spring pressure. It slides on greased rails. As you turn the lens focus ring, it should move in and out smoothly and obviously about 4-5mm.

 

IF - the return spring is broken, or too weak with age - or the grease on the rails has clotted with age/lack of use, then the bar often gets stuck at infinity (position closest to the camera). You can try pushing that brass rim straight forward with a thumbnail to see if your can break it loose to move freely. That may enough to get it moving freely in both directions again. If not, then it needs a CLA to 1) have the spring checked and perhaps replaced, and 2) have the old grease removed and replaced with fresh grease that won't act like glue.

 

Or, of course, return it as non-functional. Up to you to juggle the headache of a CLA, the headache of returning it, the price you paid, the additional price of a CLA, etc.

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Just keep an eye on it - it may now work fine for a decade or more, or it may gum up again.

 

Spending 30 minutes in front of the TV or computer (or other preferred diversion), working the focus ring back and forth from infinity to 1.5 meters, may help insure you've scraped any sticky lube off the rails.

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Glad to hear it is working.

 

Just another thought...if a hair dryer/blower is handy, you might lightly pass it over the rear several times to warm up any congealed grease. It is a temporary fix of course, but sometimes that "fix" will last a couple of years, at which point you can decide if it is worth a cla.

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Several other M teles of "a certain age" were given a similar mechanism. 1960s Elmarit 90mm, the early versions of the 1980 75 Summilux and 90 Summicron. It was a weight-saving trick (instead of a full cylindrical tubular cam reaching 2-3 inches, the cylinder was cut down to a narrow push-bar 2-3 inches long). Saved maybe 1-2 ounces (30-60g) of weight.

 

The more recent APO-Telyt 135 and APO 90 Summicron also have a cut-down push-bar cam, but I don't know if they are as "spring-dependent" as the earlier mechanisms.

 

http://www.kenrockwell.com/leica/images/90mm-f28-elmarit/D3S_9822-1200.jpg

http://www.richardcaplan.co.uk/UserFiles/Images/D_05_03_IMG_0072_2017.jpg

https://dgssofat444fe.cloudfront.net/169568-05.jpg?mtime=20170607134235

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