Coating Loss - "Meh", Bad..or "Really" bad

[Chinasaur]

So...I've been reading for a bit and have a question....

If one DOES manage to remove coating....what's the result?

Does one remove the rest of the coating or just exhale slowly and step backward from a "wrecked" lens?

'Jes kinda interested....

[Brian Sweeney]

I've done this before. Do this if damage to the coating is causing more problems with the image than just reflections.

I removed the coating on the surface behind the aperture of a 1939 Carl Zeiss Jens Sonnar, had been damaged by oil.

Wide-open at F1.5:



And at F4:



I have lenses, a Rigid Summicron, with just the center of the damaged coating removed- done professionally.

It's no big deal, use the lens. Transmission through the lens will drop slightly, a little over 2% for each surface with coating removed.

[myM8yogi]

Does anyone know of a laboratory who offer anti-reflective coating of lenses as a professional service?
I might consider it for my J3.
It would seem from this link that it may be possible: http://www.harisingh.com/newsOpticalARCoating.htm

(This would be a good time for our optician RFF members to crawl out the woodwork. Please advise.)

[rxmd]

Originally Posted by myM8yogi

Does anyone know of a laboratory who offer anti-reflective coating of lenses as a professional service?
I might consider it for my J3.

Your J-3 should be multicoated already. What do you want to accomplish?

That said, ARAX in Kiev at least used to offer this service - I have a formerly-single-coated Mir-3 65/f3.5 wideangle that was multicoated by them. I'm not sure if they still do.

[jamesk8752]

Originally Posted by myM8yogi

Does anyone know of a laboratory who offer anti-reflective coating of lenses as a professional service?
I might consider it for my J3.
It would seem from this link that it may be possible: http://www.harisingh.com/newsOpticalARCoating.htm

(This would be a good time for our optician RFF members to crawl out the woodwork. Please advise.)

John Van Stelten at Focal Point, Inc. (http://www.focalpointlens.com/fp_intro.html) specializes in cleaning and recoating lenses. He's working on a Summicron 50/2 type I in collapsible M mount with heavy cleaning marks for me. John is highly skilled and his recoating service does not come cheap; you'd be better off buying another copy of a relatively inexpensive lens like a J3.

Regards, Jim

[myM8yogi]

Thanks RXMD.

My J3 is a 1953 vintage. It really does not look multicoated. Certainly not a modern coating.

[rxmd]

Originally Posted by myM8yogi

Thanks RXMD.

My J3 is a 1953 vintage. It really does not look multicoated. Certainly not a modern coating.

Does it have П engraved into the ring around the front element, next to the lens name, focal length and aperture? That's abbreviated for просветлённый, "coated".

I don't think KMZ made any uncoated J-3s. Even the late 1940s models labeled ЗК were coated.

In all probability it's not a "modern" coating on those early lenses, but that wouldn't make too much of a difference anyway with a four-element lens, I guess.

[Gabriel M.A.]

My Canon 50 f/1.2 LTM had one of the internal coatings in a sorry state (a previous owner tried to "clean" it with zeal) to the point it made the image wide open very very soft. Had DAG remove what was left on that element, and cleaned it up. Good as new.

Although, I reckon it's time to clean it again...it's been about four years since then.

[Brian Sweeney]

I have never seen a Jupiter-3 that left the factory with multi-coated optics. I've seen them as late as 1986.

The 1953 J-3 is single-coated on all surfaces. Sonnar formula lenses have few air/glass surfaces, and a Single-coated Sonnar loses very little in the way of transmission compared with a single-coated Planar.

I believe Arax ceased operation, the equipment used to coat optics was sold off.

[peterm1]

Years ago I had a Nikkor 35mm f2.5 (underwater lens for a Nikonos) that had a spot on the lens where it was missing its coating. Had it from new (not that I could get Nikon to do anything about it). When I used it above water I found that this spot tended to flare very badly especially with any backlighting. In fact I came to the view that it was worse than losing the whole coating as this spot was jsut often visible as an area of flare or less contrast. You will be able to sue such a lens but in some situations it will compromise the result.

[rbiemer]

Arax is still selling their tweaked Kievs (60 and 88) but I do remember a couple of years ago getting an email from Mr. Vartanyan that they had stopped coating lenses.
Rob

[Brian Sweeney]

I have seen post-war "transition" Sonnars with uncoated optics. I believe they were "cobbled" together before regular production was restarted. But all of my Russian J-3's and ZK were coated.

[Brian Sweeney]

The J-3 lends itself to having the front element replaced, is easy to do. I am using a 1955 KMZ with a 1983 Valdai front element. The latter can be bought fairly cheaply.

John Van Stelton's polishing and recoating service is amazing. I just got back an early "Hot Glass" Summicron from him. Perfect.