How to open a canon 50mm 1.8 lens?

[kevinbb]

Hello:

I have just recieved the tower type 3 (nicca) RF from e**y. It is
not in very bad shape (except the collar around the shutter button is missing). 😛

The canon lens comes with it is not bad as well. The front and rear elemetns are very nice, but I found quite a number of concentric 'marks' on the inner elements.

I know this lens is notorious for developing haze and inner element separation. How can I open the lens so as to clean it up ? (I hope that is NOT the separation problem.🙁)

Any information is very much appreciated.

Kevin

 

[Sonnar Brian]

You will need an optical spanner, available on Ebay.

looking at the back of the lens, the optics module is held in by a retaining ring. Remove it, optics module drops out as one piece.

The rear module should also come out as a unit, using the spanner.

On an older Serenar lens, I had to use some very thin needle nosed pliers to reach in and grab hold of the slots for the rear group. You'll know if you encounter it. I use a pair of Craftsman needle-nosed pliers, with the tips bent at an angle. Makes a cheap Spanner.

 

[kevinbb]

Thanks for your rocket - fast assistance, Brian.

Mine is the later (non-collapsible) version. It seems your suggestion is spot on.

Thanks again.

Kevin