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View Full Version : Repairing lens 'dings' and other problems



DKirk
26-Mar-2012, 12:35
I've managed to buy a Linhof selected Symmar-S for 50. With a couple of problems, 1, there are a number 'dings' to the filter ring of both cells. And 2, the copal-1 shutter cannot be cocked or fired, but the mechanism does allow it to open to focus.
Does anyone know if there is a suitable tool to straighten these dings out?

It's a secondary concern but does anyone know a competent repairer in the UK? - I have an older compur shutter that the cells fit and it seems staightforward enough to transcribe the f-stop settings.

rdenney
26-Mar-2012, 13:21
The metal has been stretched so you'll never get the dings completely out. But I have removed such dings in the past using a wood dowel of slightly smaller than filter size, and rolling it along the threads with the outside of the barrel on a hard surface. One hand on the dowel and one on the lens controls both. Cover the end of the dowel with felt in case it touches the glass. It takes a pretty good amount of force, but not so much that it pushes the ring out suddenly--the idea is to achieve just a little on each roll. With the lens and the dowel rolling together, there's no reason for the wood to slide against the threads and it shouldn't damage them. The hard surface should be very smooth, very clean, and very hard. I might put a strip of tape around the barrel, too. A scar will almost always remain, but I've been able to restore the barrel well enough to accept filters again.

If this scares you in any way, don't attempt it. If it doesn't scare you at all, it should.

I'd test the lens in the Compur shutter first, however, to make sure it's worth the effort.

Rick "who thought all Linhof Select lenses of earlier vintages came in Compur shutters" Denney

John Schneider
26-Mar-2012, 13:32
Also, always cover the glass before doing any rim straightening; tools do slip. I use a layer of the low-tack blue masking tape.

Vick Vickery
26-Mar-2012, 14:14
for dents toward the inside of the rim, I've had good luck by cutting a curved support to fit the outside of the lens rim to support the rim while using a dowel as a punch on the inside of the dent and tapping the dowel with a light hammer. Go slowly, and you can eleminate the dent almost completely...the dowel end conforms to the thread and displaces the metal outward to its original position. In most cases, I've even been able to use filters again, although I really use mostly Series filters in slip-on adaptors or gel filters in slip-on frames.

DKirk
26-Mar-2012, 14:47
Cheers for the help so far, I'm fairly comfortable attempting these repairs now. It would be nice to use screw in filters, but failing that I can use the super hi-tech :rolleyes: method of using blue-tac or other such product

Peter J. De Smidt
26-Mar-2012, 15:50
http://www.micro-tools.com/store/item_detail.aspx?ItemCode=LV1
http://people.rit.edu/andpph/text-ding-repair.html
http://www.kyphoto.com/classics/filterringtool.html

Uri A
13-Apr-2012, 18:26
Those links are great thanks Peter!