Dismantle and clean RF Canon 50/1.8 LTM

Marla60 · 06-13-2008

Hello,

My canon 50/1.8 has some haze and it needs to be cleaned inside.
But I never do that before.

How do this?

Thanks for your help

TheHub · 06-13-2008

Look at the persons location, English may not be their first language

I'd like to know how to dismantle the lens, too.

ferider · 06-13-2008

The haze is most likely on the surface behind the aperture.

Get a lens spanner (US 20-30 or so on ebay). Take off the brass ring that you see from behind, next to the RF cam. Than you can take the lens barrel out of the helix.

Then, using a cleaning cloth and some force you can take off the rear element group for cleaning. Before you unscrew it, mark it so when you reassemble you know how tight to go.

The above works for both, chrome and black/chrome versions of this lens.

If it is the black/chrome version, you will find a tiny screw in front of the aperture ring. If you take this out you can remove the front group of the lens without spanner, and get access to surfaces behind and in front of aperture for cleaning.

Best,

Roland.

dexdog · 06-13-2008

Roland has provided excellent directions concerning how to disassemble and clean this lens. It is really pretty easy if you have a lens spanner. Also the coatings on old Canon lens are usually fairly hard, and so damaging lens coatings is not a big issue provided that you use gentle cleaning agents and minimum force to remove the grime.

dexdog · 06-13-2008

Quote:

Originally Posted by nikonhswebmaster

Marla60 welcome to the RFF!

Yes, welcome to RFF.

I see that you have a Canon P

Probably my favorite LTM camera. I won't even try to put this greeting into French- my French is even worse than my use of English

Brian Sweeney · 06-13-2008

You can also use a set of good needle nosed pliers to get the rear module out. On the chrome version of the lens, the pliers shown in my avatar work well with a hard-to-reach retaining ring.

Which version of the lens do you have? The all-chrome version is constructed a bit differently from the later Black version.

I need to remember to photograph the next one that I take apart.

Welcome to the Forum.

Marla60 · 06-13-2008

Thanks for the help and the "welcome"

And sorry for the mistakes in my sentences in english

I will try the method of Farider. I hope the cleaning will be useful.

This is the black version.
The seller told me that there was some haze on the lens but we cant see any effect on the pictures.
But it's not the case, mainly in the hight lights.
I call it the "david hamilton" effect, and I want to get rid of it, if it's possible...

ferider · 06-13-2008

Quote:

Originally Posted by Marla60

I call it the "david hamilton" effect ...

Welcome, Marla !

Roland.

Marla60 · 06-13-2008

Quote:

Originally Posted by ferider

The haze is most likely on the surface behind the aperture.

Get a lens spanner (US 20-30 or so on ebay). Take off the brass ring that you see from behind, next to the RF cam. Than you can take the lens barrel out of the helix.

Then, using a cleaning cloth and some force you can take off the rear element group for cleaning. Before you unscrew it, mark it so when you reassemble you know how tight to go.

The above works for both, chrome and black/chrome versions of this lens.

If it is the black/chrome version, you will find a tiny screw in front of the aperture ring. If you take this out you can remove the front group of the lens without spanner, and get access to surfaces behind and in front of aperture for cleaning.

Best,

Roland.

I just need a cleaning cloth to clean it? no other products?

ferider · 06-13-2008

Quote:

Originally Posted by Marla60

I just need a cleaning cloth to clean it? no other products?

It depends what the haze is. Try with cleaning cloth and maybe iso-propanol. Or Vodka (seriously

). That works in most cases.

Best,

Roland.

Brian Sweeney · 06-13-2008

I've had the best luck with ammonia based eye-glass cleaner, applied gently with a q-tip and then clean with Kodak lens cleaning paper. I ran out of Olympus branded paper.

I just cleaned a Black version of the lens for an RFF'r. The rear module came out easily. The rear element comes out of that module by taking off a retaining ring as well. IF YOU DO THIS- be sure to mark the edge of the lens to you put it back in correctly. It is "almost" symmetrical, and if you forget which way it goes on, you will get fuzzy edges on your pictures.

sockeyed · 06-13-2008

I am the RFF'r that Brian Speaks of. My lens had a fair amount of haze in it (resulting in a lot of 'glow'), but Brian cleaned it up very nicely and now it sparkles. Canon lenses, in my experience, clean up much more nicely than their Leica counterparts (which often need recoating).

Bienvenue à RFF, Marla60.

Marla60 · 06-13-2008

Again, thanks a lot for your help.

I've tested many forums on the Internet, and this one is the best one, because people know what they are talking about.

bcostin · 07-05-2008

Thanks to everyone for posting this information. I successfully disassembled and cleaned a Canon 50/1.8 that came with a VT I recently purchased. I've worked on FSU lenses but this was my first try with a Canon LTM. Everything went smoothly and the lens works great.