R lens specialist wanted.

[pgk]

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A friend has an expensive R lens in need of some attention (focus not precise). Any suggestions (based in UK but might be worth shipping elsewhere)?

[spydrxx]

Sherie Krauter in the USA did some work on an R lens of mine some time ago. Perhaps worth an email..

[LocalHero1953]

Skyllaney? A mechanical lens specialist.

Edited May 14, 2024 by LocalHero1953

[trickness]

On 5/14/2024 at 7:01 PM, spydrxx said:

Sherie Krauter in the USA did some work on an R lens of mine some time ago. Perhaps worth an email..

I wouldn't send her anything unless you like waiting for ages and hearing nothing

[bherman01545]

DAG - Don Goldberg in Oregon, Wisconsin USA is Leica factory trained. Highly recommended!

[250swb]

On 5/13/2024 at 6:56 PM, pgk said:

A friend has an expensive R lens in need of some attention (focus not precise). Any suggestions (based in UK but might be worth shipping elsewhere)?

I don't understand how an SLR lens can be 'out', what you see in focus is what you get isn't it? Not sure how it focuses different images on the film plane and on the focusing screen at the same time?

Edited September 8, 2024 by 250swb

[pgk]

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1 hour ago, 250swb said:

I don't understand how an SLR lens can be 'out', what you see in focus is what you get isn't it? Not sure how it focuses different images on the film plane and on the focusing screen at the same time?

Its a long and convoluted story which isn't worth explaining here, but it was! Now fully sorted out thanks to Newton Ellis apparently.

[Aram Langhans]

6 hours ago, 250swb said:

I don't understand how an SLR lens can be 'out', what you see in focus is what you get isn't it? Not sure how it focuses different images on the film plane and on the focusing screen at the same time?

Glad he got it all sorted out, but I am with you on this.  If it is not focusing properly the problem would be in the camera body, not the lens if my thinking is correct.  Focus screen not aligned properly so it does not match the film plane.

Edited September 9, 2024 by Aram Langhans

[pgk]

6 hours ago, Aram Langhans said:

Glad he got it all sorted out, but I am with you on this.  If it is not focusing properly the problem would be in the camera body, not the lens if my thinking is correct.  Focus screen not aligned properly so it does not match the film plane.

No, this was not the problem. As I said, too complicated to explain, but the lens needed corrective (and quite expensive) work to ensure correct focus at all distances. It now works perfectly following repair. 

[250swb]

On 9/9/2024 at 9:48 AM, pgk said:

 too complicated to explain, but the lens needed corrective (and quite expensive) work to ensure correct focus 

Give it a go, there are some nerds on the forum that certainly know far more than me and most of us, but essentially the explanation helps other people if they ever have a similar problem.

[pgk]

11 hours ago, 250swb said:

Give it a go, there are some nerds on the forum that certainly know far more than me and most of us, but essentially the explanation helps other people if they ever have a similar problem.

Well, prior dismantling and reassembly may have had something to do with it - that's probably enough. I cringe whenever someone on the forum mixes DIY and lenses. Without precision collimators and a good understanding of how lens' mechanics work and can be adjusted things can go very wrong indeed.

[250swb]

44 minutes ago, pgk said:

Well, prior dismantling and reassembly may have had something to do with it - that's probably enough. I cringe whenever someone on the forum mixes DIY and lenses. Without precision collimators and a good understanding of how lens' mechanics work and can be adjusted things can go very wrong indeed.

Thinking back I once got an eBay bargain of an Olympus 50mm f/1.4 which did give some weird results at certain distances but you could see something was wrong on the screen. When it was disassembled it was found one of the elements was loose and 'floating' but not in a good way, but even weirder there was no sign of it being serviced and the lens itself was mint. Makes me wonder if it had been a rouge lens from it's manufacture. 

[TomB_tx]

It can happen. The Fat TeleElmarit I bought in 1968 began giving disappointing results after a few years. Eventually tested is for plane of focus and realized there was no really sharp area, and images were washed out - so it sat in a drawer for a few decades. Finally sent it to Gus Lazzari to see what could be done, and he reported an element was out of position, It came back like new and had been outstanding since. I figured it must have had an undetected jolt at some time that moved a poorly retained element,

[spydrxx]

I had a (LTM) Nikkor H-C 50/2 which was producing terrific results, including the extended close focus, on my mirrorless body, but when I put it on a film Barnack, it wouldn't focus. I sent it to DAG, who informed me that prior to my purchase a person, previous owner or inexperienced technician, had reassembled it with an element inserted backward. Works fine now on anything I toss at it.