Canon rangefinder lens servicing

Canon lenses for their rangefinder line most often are found in not so mint state (you might want to look up my posts about haze/fungus) … well at least for us bargain hunters.

Many older Leica thread mount lenses from Canon suffer from haze and fungus.

There are many theories around why haze is common … many blame it on the evaporation of the lubricant used, or the type of glass used which is prone to corrosion by moisture. It tends to form on the element face above or below the aperture. In most cases haze can be remove with just a simple cleaning, but if it attacks the glass or coating the only way to fix this is by getting the element polished (which is very expensive to get done). The lens can sometimes still be usable but it will affect contrast and sharpness of the image … makes for an OK soft focus lens for portraiture.

Fungus, well that’s just due to the storage condition of the lens. Many of those found and up for sale have been lying around in some closet for decades.

For those that want to attempt cleaning the lens (I say attempt as in many cases the haze or fungus will never be removable), these older Canon lenses are not that difficult to take apart. Note that there are many other websites/blogs that go over this already, but I thought I would add it to my blog anyway.

Here is info on the Canon 50mm f/1.8 chrome model.

Tools: spanner wrench, rubber lens tool, blower, lens cleaning stuff, Ronsonol.

All access can be done by going through the back.

Unscrew, counter-clockwise, the retaining ring and pull it out.

You can then pull off the entire focus helix assembly.

Note that there is a brass shim around the lens collar. Do not lose or damage this. This is a specifically sized spacer.

Note that there is a brass shim around the lens column.

Do not lose or damage this as it is a specific sized spacer for the lense.

You can clean some of the old grease off of the focus helix and apply new stuff.

I didn’t go as far as complete disassembly to do a thorough cleaning.

The rear elements are in two pieces

Unscrew, counter-clockwise, the top lens group.

Unscrew, counter-clockwise, the lower lens group.

Now you have access to the rear of the aperture. I you open up the aperture you can then have access to the rear of the front lens element group.

Put some Ronsonol on the aperture blades to clean off any oil (if there is any).

Put everything back together one step at a time. Each time you should visually examine for dust.

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I got GAS and it’s time to let it out.

It happens … G.A.S.

As I am not that socially web aware I didn’t pick up on the GAS acronym while glancing over forum posts. Gear Acquisition Syndrome.

I love to buy Gear, but it usually has a purpose … with the case of repairing items, it has a limited lifetime. That lifetime ends when it is repaired/restored.

So for me, I am at that point where I have too much Gear. Now is time to get rid of them and obtain new Gear !!!!

Actually GAS is exciting. Love the GAS … especially cheap GAS … GAS is good, well I should say self controlled GAS is good. When GAS gets out of hand it creates collections. I have never really understood the use for collections … even though I do have a small collection of cameras. What good is collecting when it is just sitting there ? Is it the thrill of saying “I have a xxxx and you don’t” ? Is it the never ending struggle of achieving the greatest number of cameras over the next collector ?

I don’t know … all I know is that I don’t have chronic GAS, which is good as there is always a relieve valve.

 

Newest tools

Well, I got a new tool for Xmas.

A jewellers hand vise from Lee Valley. Not sure exactly what use I will have for it, but there probably will be a time when I will need it (like all other tools that you don’t have but needed).

 

Another tool that I will be getting soon is a Sony NEX-3. Well not so much as a tool but more as a device that I can use to check my LTM lenses quickly … and it also doubles as a camera.

Leatherette

leath•er•ette (ˌlɛð əˈrɛt)

n.                 a material constructed and finished to simulate leather.

 

The material used on the Minolta Autcord, and many other cameras of that time, was a vinyl material with a leather pattern. Older Leicas had a covering made of vulcanized rubber (usually people refer to this as sharkskin vulcanite) and later models used vinyl material. Lacquer was a common adhesive to attach these materials to the metal camera body.

Over time these materials become brittle. You have probably seen many old cameras with the leatherette peeling in the corners or random sections missing … so you would naturally assume it would be easy to remove … NOT !!!

The leatherette that is already peeling away means that the lacquer/adhesive underneath has disappeared making it very easy for those pieces to flake off. I had a Leica IIF where the vulcanite had shrunk so it was peeling away on the front. I was able to pull off the entire piece that wrapped around the camera intact.

Most of the time you have leatherette that is still attached to the body and becomes a pain to remove.

Some say to use “softeners” like Acetone to break down the adhesives … problem is that the adhesive is underneath.

I looked into tools for this.

Chopsticks shaved down … worked for a couple of scrapes then became dull.

Screw driver … ones with a sharp point are not wide enough, and sometimes caused grooves in the metal … though a Dremel with a grinding wheel makes easy work on those cheap screwdrivers to modify them.

Then I encountered a suggestion on the web … dental chisels.

 

 

 

Sharp and somewhat wide, and some not sharp … these worked great and continued to work without dulling quickly.

I picked up a pack of different types for less than $20.00

The larger pieces of leatherette on the Autocord came off in single pieces, while the Minolta-35 was brittle so I ended up with a table splattered with flakes.

 

Recovering is the easier part. You can get leatherette pre-cut for many cameras or buy a sheet and cut yourself (see About the tools).

If you are cutting yourself, you can get sheets with or without adhesive.

You can really use any flexible material you can think off (that is not too thick … most cameras are good with 0.4 to 0.7mm thickness).

 

Clean off the body with Acetone.

Use painters tape mask off the areas. Apply many layers.

Cut around to edges with a very sharp knife. If you make a mistake, just apply more tape.

Once you are satisfied with the cuts, peel off the tape. Then apply the tape to the new covering material.

Use a sharp knife to cut out the pieces.

For adhesive I use Pliobond … yeah it does smell funny, but it goes away after a while.

I will show off the re-covered camera later, as I am still working on it.

 

Minolta – winder side

I have not had an Autocord that I needed to repair the winding gears, but I do clean the gears underneath.

Tools: dental chisel, pointy tweezers, and slotted screw driver.

You will note that my Autocord is missing the knob on the winding arm. I used my parts camera to replace it.

Unscrew the strap lug and the back door hinge.

Use pointy tweezers to unscrew (anticlockwise) the locking screw for the winding arm (note that there is a washer underneath it) and the winding reversal button.

You will need to remove the leatherette covering from this side to reveal the five screws. This will take you some time if you want to remove all of it, so you can just work on the areas around the screws and come back to it later.

Remove the five screws and pull off the cover plate.

Note the bottom will lift up as there is a spring underneath.

The indicated area is where you will find the winding shaft spring, set plate and gear.

You can clean off the gears with Ronsonol.

Before you put the cover plate back on, clean the backside of the windows and add a dab of Super Lube around the center wind post.

The adventures of this guy who tries to restore and repair vintage photographic equipment … and wins (most of the time).

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