Sun Telephoto 135mm f3.8 in Exakta Mount.

mo · Expire: 2016-07-30

It was not me who suggested heat....but I am thankful you have basically made a step by step for someone else who may have the same problem Very Happy

When it comes to using different types of helicoil grease do you also take into account how long it will last?

Kathmandu · Expire: 2012-04-08

trifox · Expire: 2014-05-29

I have not made any progress yet and congrats to yours!

It's almost impossible to unscrew it in my case..

tf

Univer · Joined: 30 Jun 2009 Posts: 282

Congratulations - nice work!

Just chiming in briefly to say that this lens was in fact made in M42 mount, as was the 9cm Sola.

I reckon Sun lenses of this vintage just tend to be difficult to get into and restore. Happily, my 13.5cm and Sola haven't needed this kind of attention. On the other hand, my Sun Sparon was returned untouched by keh, with a note that said it couldn't be worked on.

(I've found another restorer who may be willing to take on the challenge, but I haven't decided whether or not to proceed.)

Cheers,

Jon

Kathmandu · Expire: 2012-04-08

Thanks Stan and John.

Jon do you have images of the lens? What's wrong with the lens? Very Happy

Univer · Joined: 30 Jun 2009 Posts: 282

Hi,

Here's a link to a couple of photos.

One problem is fungus: a fairly localized case, but (apparently) between cemented elements - hence keh's determination that the lens couldn't be cleaned.

Another problem is in the aperture mechanism: I think one blade is either detached or broken.

And the final problem is a stiff focusing ring.

Since the uncleanable fungus is the limiting factor here, I haven't bothered trying to do anything about the other issues.

When I first received the lens, I tried everything I could think of to open it up, but I couldn't get anything to budge. (I should be clear that I didn't start removing random screws, since that kind of approach seldom seems to end well for me.)

I did locate one technician who was at least willing to look at the lens, and who apparently disassembles and recements cemented elements as a routine matter, but the service charges were rather high - and he wasn't at all sure he'd be able to do anything about the aperture problem. So I'm still trying to decide how to proceed.

It's such an interesting lens - I'd love to get it back into working condition.

Cheers,

Jon

Kathmandu · Expire: 2012-04-08

Sounds like a good challenge for someone . Realistically it would take quite a bit of time~the fungus may or may not be worth even attempting to clean, or even possible without ruining the element, sadly.I am very impressed with the quality of the Sun lens , at least one I have.

I bought the same lens in an all chrome version ,with working focus and aperture. I plan on opening it up and cleaning and relubing it, sometime in the future.I do not like the organic grease of old in it at the moment-and want to clean it off and relube it with the synthetic stuff.