Disasemble front element Tokina 80-200mm f4

BobbyB · Joined: 26 Dec 2014 Posts: 12

Hi, I have a Tokina 80-200mm f/4. I've removed the front element but it consists of two lenses. Only I have no idea of how to separate them. (There is some fogging in between)
The back lens seems to be held by a screwed in ring. but it wont budge, and there are no notches for using a tool.
Does anyone have any experience or advice on this. Maybe they're glued?

Sorry if I use the wrong terminology. It's my first lens clean and my first post Smile

BobbyB · Joined: 26 Dec 2014 Posts: 12

I read that you can't post images on your first post. So I'm replying to my own post. Here are the images:

sceptic · Joined: 01 Jun 2013 Posts: 255

Have you tried unscrewing the ring in front of the front glass? It looks removable, but could possibly be glued with thread locker (which can be dissolved with acetone).

BobbyB · Joined: 26 Dec 2014 Posts: 12

Thanks for the tip.
I tried unscrewing but everything is locked solid. But there seems to be some kind of glue residue, so maybe you're right.
How should I apply the acetone? With an eye dropper?
Or can I just dunk the whole thing in? Won't that remove the paint?

sceptic · Joined: 01 Jun 2013 Posts: 255

Don't dunk the whole thing in acetone, use an eye dropper instead. A drop or two applied at the bottom of the ring (so that it seeps into the threads) should be enough). You may need to wait a minute or so for the glue to dissolve, before trying to remove the ring. Be careful when gripping the ring; if you apply too much pressure on a small area, you could deform the (thin) metal. Try to grip the ring "evenly" around its circumference. Good luck!

BobbyB · Joined: 26 Dec 2014 Posts: 12

Worked like a charm! I can now access the two lenses in the front elements.
As this is my first cleaning job, it gives me some encouragement to continue Smile

Thanks!

sceptic · Joined: 01 Jun 2013 Posts: 255

Glad to be able to help!