20x front lens
 

Has anybody had any problems with the front lens element coming loose? I was cleaning my lens and it popped out! Now it is just loose and rattles around. Does not effect image quality, but I am affraid to use it now. Anybody know if this is a possible DIY fix?

Wow, here's a new one. I don't think I've ever heard of this happening.

I'd definitely send the lens in to Canon on this one. Optics is an incredibly precise science, and so DIY fixes are not really a good idea when it comes to lenses.

This might sound insulting, but not meant to be.
Are you absolutely sure it's the lens, and not an ND filter that came out?

Not insulting at all. I'm positive, it is the front "coated" lens. I can physically move it with my finger.

Damn! Then I am as speechless as everyone who didn't post here. Call Canon, now.

If the front element of your 20x popped out - its' out of allignment now and needs to be fixed. Only Canon can do this.

Despite all of the recommendations to send the lens into Canon, I decided to throw caution to the wind and attempt the repair myself. I am pleased to announce that the surgery was a success.

I very carefully removed the 4 screws on the front of the lens. I then removed the front shroud that holds the front glass in place. I immediately realized that there is a large C-style clip that holds the element in place, mine had apparently been pushed through due to improper cleaning of one of my crew members (probably me, but I'll never admit it). I very carefully insertd the lens in the shroud and replaced the c-clip. I used compressed air to clean the main lens assembly and then re-attached the shroud with the four screws.

I was sweating the whole time, but the lens is back together with no problems what-so-ever! The main thing that I can stress if you try this is to make sure not to nudge a single component inside the lens housing when you have the front shroud taken off. I don't know that anything would get screwed up, but it just looked like a good idea not to let it move around.

Oh, by the way, there is no way that alignment can be adjusted on this front element. The c-clip holds it in a specific location that cannot be adjusted. So, no matter how you put the element back in the housing..... it will always fall back in the same place.