CZJ Tevidon 50/1.8 disassembly???

ForenSeil · Joined: 15 Apr 2011 Posts: 2727 Location: Kiel, Germany.

Hi!
I have this lens since a few months but never used it because it's not in C-Mount.
Now I've made an Tevidon-C-Mount adapter like this one Click here to see on Ebay in my latest DIY project.

After changing the mount I recoginzed the the focus of my 50mm Tevidon is stucked! Yes! Completly stucked, you can't even move it with a pipe wrench! Crap - lens was bought as fully working and I'ver never test the focusing ring Evil or Very Mad

!

How to disassamble this lens? I can easily remove front element and it's bajonett and aperture ring but after that there a no screws left and nothing is moving. Is it even possible to disassamble it with a stuck focus?

calvin83 · Joined: 12 Apr 2009 Posts: 7495 Location: Hong Kong

There is two types of Tevidon 50. One with thicker focus/aperture ring. The thinner one may be similar to the Tevidon 100 described here http://www.bigeye.url.tw/big5/d_czj100_28.htm .

ZoneV · Expire: 2011-12-02

Just to be sure: There is no kind of locking screw?
Machine Vision / CCTV lenses are normaly with locked focus and iri (and zoom in case of zoom lenses).

kds315* · Expire: 2021-03-09

Try lighter fluid or WD40 inserted from teh rear end to the helicoid. Be careful not to immerse the optics. Mild heat also helps (hair dryer).

P.S.: we have an EBAY button to insert ebay links, only needs the auction number Wink