Canon 1,2/55mm S.S.C.... EOS conversion-Documentation

hinnerker · Expire: 2015-08-09

For those of you who are interested to convert a Canon FD 1.2/55mm S.S.C – lens, I wrote this article with some pictures to explain, how it could work and did work for me.

Not a perfect work in terms of cosmetical but fast and usefull,

Necessary parts:

1 Adapter Olympus OM to Canon EOS with 2mm thickness
1 tension spring of about 50mm
1 Yashica cap with diameter 57mm as later light seal
1 small ring with the same diameter as the OM to EOS Adapter or something else as a
spacer with a thickness of 0,75mm to 1mm. This controls the infinity.
you can also take some tesafilm stripes in layers to adjust. Without you will reach
behind infinity

Tools:
Mini Drill and two drills (1mm and 3mm I did use)
Some watch repair screwdrivers in better qualitiy

OK, lets start..

First of all an important thing for me was, to make the whole process reversible.
If the conversion would failed, I would make sure, the lens could be brought to his original state.

So I thought about a non destructive way of doing this conversion.

First I removed the outer chrom ring of the FD Mount. This can be done by unscrew 2 very little screws in the chrom ring, which are holding a slider that acts as a opener for the aperture if you turn the ring in the correct position to attaching the lens on the body.

Pics 1 + 2

Chrome Ring with the 2 screw hole's..

After removing the screws, you are able to turn out the chrom ring clockwise. From time to time, a small STOP - PIN will stop in one of the 3 hole's. Push this pin down.. so you can go further with the unmounting of the chrom ring.

OK, the ring is off. Attention, there falls down the little slider I described before.. this is the part, which opens the aperture when the chromring was turned to attach the lens.. No worry, its easy to bring it back in the right position if you want to rebuild the original state. But that later.

Now we can see a TUBUS-End - block with the screw thread, the chrom ring was attached on the lens body.

This Tubus – Block was fixed with 3 screws. These screws are very important for the further conversion.

Ok, lets take now the OM to EOS Mount Adapter.. compare the diameter of the Tubus-end Block with the inner diameter of the adapter…

You will find nearly the same diameter only with the problem, the Olympus wings are needless.
So this is the first part of modification. file them down !!

Now you can dismantle the Tubus-block by unscrewing the 3 screws..

After doing this, you are able to bring the OM Adapter and the Tubus Block as close together
as you want, to copy(mark the position of the 3 hole’s to the OM to EOS Adapter.
(Please make sure during this process the correct orientation of the scales on the lens for later position when attached to the camera body)

After drilling these 3 hole’s (1-1.5mm) in the OM Adapter, take the second drill (2.5-3mm) and open the hole’s nearly 1mm for the screw heads.

After doing this… the most work is done.

The Tubus-block with the screwthread holds the complete lever mechanism for the aperture coupling to a Canon FD Body. After unscrewing this, you can detached the whole mechanism in one part.

So, now you are ready to attache the OM to EOS Adapter to the lens by taking the 3 screws and fix the adapter there, where the tubus-block was in place.

But pay attention, you will come far behind infinity !! And the mirror of a 5D will hang!!!

Lets do some thoughts:

The Tubus – block has a thickness of 5.5mm

.. the difference between FD (42mm) and EOS Mount (44mm) is 2mm. The OM Adapter takes another 2mm of the 5.5mm…

In theorie you should attach a spacer of 1.5mm between lens tubus and OM Adaptor to get infinity and the position of the lens than should be right.

But that’s only Theorie..
I didn’t know, if the Lens reaches infinity on a Canon FD Body, so I decided to attach the OM Adapter without a spacer and have a look, what happens.

The result:

After experimentating a bit with some spacer.. a 1mm ring works fine for me.

I tried this out with my Canon EOS 5D MKII in LievView – Mode.

This can be different from lens-copy to lens-copy.

OK, this is the first part of the modification.

There are 2 other problems:

The Aperture controls are gone… bad.

But this problem is so easy to solve, I couldn’t believe that first.

The only thing you need, is a tension spring of 50mm. This was attached as shown in this picture. The tension spring pulls the aperture in close direction, and a small slider, attached on the Aperture rings opens the aperture with each click.
So this problem is very easy to solve. A picture says more than 1000 words... have a look at both ends of the tension spring and the black lever, which press the fork when turn the aperture ring in 1.2 direction !

The second problem is to find a “light seal” for the construction. Also easy..
After looking around in my camera toolbox I found a rubber frontlens-cap from Yashica with the correct Diameter of 57mm.

Not very nice, but works great and i will find some other possibilitys to make them look more professional.

Remember, this was a fast, quickn dirty conversion to find out, this could work.

Work was done…

There is an additionally possibility to fine adjust the infinity point behind the engraving frontring of the lens. After removing the name ring, there is a key-locking ring, for adjusting the focus part of the helicoid. But i didnt have the tools for doing this at the moment. I will do this later.

I hope this was interesting for you and my english is not as good as it should be for writting such articles...

Enjoy..

Cheers
Henry

LIMITATIONS: You can use the lens in the whole range from near to infinity only on APS cams because of the mirror issue. If you file down about 1mm of the mirror for a Canon 5D or 5D MKII, you can reach infinity without any problem. I will do this, if my 5D MKII is out of warranty. During this time, i will use this superb lens only within 10m or at infinity in LiveView-Mode.

LucisPictor · Expire: 2013-12-03

Thanks, Henry!

sichko · Joined: 20 Jun 2008 Posts: 2475 Location: South West UK

Thanks for the description. I shall probably never work on such a lens but it's always a pleasure to see other people's ingenuity.

pau.cc · Joined: 18 Dec 2009 Posts: 23 Location: Madrid

Amazing!
I'll take a look deeper at a later time!
Thanks!

francotirador · Joined: 17 Sep 2009 Posts: 894

Thank you very much for this example.
Now I just want to see your photos with this lens.
Greetings Wink

hinnerker · Expire: 2015-08-09

hinnerker · Expire: 2015-08-09

Ok, now some quickn dirty shots after mount conversion.

First of all a "extreme" shot.. at f/1.2 on dayligt, snow and reflecting surfaces.. glowing is normal for a 1.2 under this conditions...

First the scene in total..

Now a crop out of it to show the "Glow"...

And this is a crop from a shot, using a bounced flashlight, f/4.0..

and this is a crop from the crop ... i should clean from dust.. Very Happy

Will add some more and better pics, if the wheater conditions are better.

Cheers
Henry

bojan · Joined: 22 Feb 2010 Posts: 2 Location: Melbourne, AU

Hi,
Recently I modified my "new" 100mm Canon FD SSC F2.8 lens to suit my EOS 400D (by replacing the FD mechanism with $10 EOS adapter from ebay).
The only thing remained to be done is to adjust the focus (to reach infinity) .
Anybody could tell me how to get to the focus stops?
I gently tried to dismantle the lens from the front (by removing the plastic ring with SSC etc letters) but I could not get to the stops this way..

hinnerker · Expire: 2015-08-09

bojan · Joined: 22 Feb 2010 Posts: 2 Location: Melbourne, AU

Hi Henry,
Thank you Smile

I only saw your answer now (June).. because I in the meantime I already sorted out the problem (the focus barrel on 100mm is held in place by retaining threaded ring, and not by 3 small screws as on 50mm)
But nevertheless.. thank you again Smile

viniciuspedrozo · Joined: 17 Apr 2009 Posts: 19 Location: Brazil

Maybe is more easy change mount EF of Camera, no? I remove FD Mount of old camera and will try install on 5D.