How to tighten the focus ring on 28mm cron ASPH???

[Eastgreenlander]

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Hi, My work horse lens is my 28mm M summicon ASPH, last version. The focus ring has become very loose, meaning it is too easy to move from closest focus distance to infinity. I would like to tighten up the focus ring so it does not move so easily. I´ve tried to search this topic but no results. Do anyone know how to do this? Thanks 

[jaapv]

Yes. Send it to Leica. I do not think this lends itself to DIY.

[Eastgreenlander]

Yes. Send it to Leica. I do not think this lends itself to DIY.

Thanks for your answer Jaap. I send that lens for CLE 4 years ago. So expensive. I was hoping I could do it my self. I guess not  . 

[colint544]

Had the familiar loose front problem with my 28mm Summicron, rather than a too loose focus ring. Used a tiny screwdriver and some Loctite, but the screws kept eventually coming loose, as did the front of the lens. Even handling it with kid gloves, and abandoning the hood, it kept happening. Drove me crazy, because it's such a great lens other than that maddening design flaw.

 

Eventually I succeeded in dropping the lens onto the soft sandy beach in Sopot, Poland. It landed face up - the back cap wasn't attached - and the greasy brass threads and internals were packed with sand. I picked as much out as I could, but there was finally no way to avoid having the lens professionally disassembled.

 

Anyway, I dealt with the wonderful Andrea Frankl (I think that was her name) at Leica. I asked if they could fix the problem of the useless tiny screws on the barrel while they had the lens, and she assured me that it was a very common problem and that they'd fix the lens barrel "good and tight".

 

Sent the lens to the factory. Got it back a few weeks later. It was like new - better than it had been before. No sand, smooth focusing, and no loose front. I can't see any screw heads in the holes where the screws were any more. They seem to have been filled with some sort of hard black compound. I don't know what they did, but it works. It's been four years since Leica repaired the lens, I use it all the time, and it's stayed rock solid.

 

Bite the bullet and send your lens in. You'll get it back, it'll be great, and you'll not need to worry about it again. If you've had any problems with the screws, I'd get them to do that while it's in. And I'll use this post to salute the great and personalised service I've received from Leica on the two occasions I've needed it.

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[Eastgreenlander]

Thanks for your story colint544. It too expensive for me to send it in for CLA already after 4 years. I think I will wait a couple of years. Otherwise my 28cron asph is perfect! Nothing is loose, Its just a minor issue in handling the focus ring. Going from 28mm cron to my 35mm lux FLE or 50mm lux apsh, is a world of difference in the focus dampening. The 28cron is still my main lens though. 

[Jeff S]

Call in advance to discuss repair and cost, if any... then decide. I don't anticipate an expensive fix.

 

Jeff

[oldwino]

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I had the same problem with my version 3 Elmarit 28mm. I sent it to DAG here in the U.S. and he repaired it for less than $150, in about 2 weeks time. It's like a new lens now.

[ModernMan]

Interestingly, if you are adventuresome, the "tightness" of the focus action can usually be adjusted by the use of fluorocarbon "damping grease", if there is not an underlying mechanical issue requiring correction. For an application like this, you can get a set of damping greases that have a range of damping factors, ranging from "loose" to " tight". They are typically packaged in syringes for precise application. Ideally, you would disassemble the helicoid, clean it and then apply the desired grease. But, if you're really careful, you can just inject a little grease directly on to the helicoids, move the focus in and out a few times to mix the new grease in, and by selecting the right grease somewhat change the damping factor.

 

Although not for the faint of heart, its easier than it sounds and can work like a charm. Apply very very sparingly or be prepared for a tedious clean-up. There is very little grease on the helicoids to begin with -- less than appears. Avoid getting any on the glass or black flocked surfaces. The procedure best done under a 10x-20x stereo microscope. Of course, you have to either have a lucky/good guess as to which damping factor to use, or be prepared for "convergence by successive approximations". BTW, my assumption is that the Leica lenses are lubricated with this sort of damping grease from the factory.

 

See https://www.lubekits.com/?load=grease.

[Jeff S]

BTW, my assumption is that the Leica lenses are lubricated with this sort of damping grease from the factory.

 

See https://www.lubekits.com/?load=grease.

As I've written elsewhere, my 50 Summilux ASPH suffered from tight, 'sticky' focus action, which made fine focusing adjustments problematic. I sent the lens to Leica NJ and they could not significantly improve the situation, despite replacing the grease, among other things. I even spoke with the technician, who was reluctant to make other adjustments for fear of making matters worse.

 

I then sent the lens to DAG, and he had it back to me in perfect working order in a week, charging a mere $90, including shipping. His solution was to replace the grease with his supply of the old Leitz grease, which apparently is no longer used at Leica. Sometimes new isn't better.

 

Jeff

[rramesh]

I don't believe anything about Leica lends itself to a DIY fix. Even sensor wiping