Can the front glass on a broken lens be repaired?

Question

I just newly broke this glass on my lens tonight. Wondering if I need to buy a new lens or if I can repair this. It is a Canon EF 85mm f/1.8 USM. This is my favorite lens to use for portraits!

Answer 1

Although it is hard to tell for certain from the included image, it looks like the only thing broken is a filter placed on the end of the lens. The first element of the EF 85mm f/1.8 lens itself is just past the ring of baffles below your broken filter.

Remove the filter ring, clean off any remaining pieces of the filter being careful not to scratch your lens while doing so, and you should be good to go.

If you are concerned that the lens may have been damaged by the event that shattered the filter attached to it, test the lens and include a detailed description of what you found wrong with it if you send it in to a service center.

In the above linked blog entry How to Test a Lens, Roger Cicala, the founder and chief lens guru at lensrentals.com, says this:

BTW – if you send a lens in to factory repair with “This lens is soft” as the only description of the problem, chances are extremely high that it won’t be fixed. Trust me on this. We have 20 lenses a week go in to factory service. We’ve learned.

My experience has been the same. If I had read Roger's words before the first time I sent a lens to Canon factory service with the description "please align lens", I probably would not have gotten it back in the same condition it was in when I sent it. After later sending it back with a more specific description¹, including sample images that showed the problem, it came back fixed.

_{¹ Something like: The lens demonstrates severe tilt with the lower left corner of the frame focused much closer to the camera than the center of the frame. The upper right is focused further from the camera as one moves from center to corner until details get too soft to tell where it is focused.}

As for whether "protective" filters really are or not...

For more about the overall subject of To filter or not to filter (for lens 'protection'), that is the question, please see this answer to is uv filter a must? here at Photography at Stack Exchange. There are lots of links to a plethora of questions/answers here and resources elsewhere on the subject. While there are times and places (sand/dust storms, at the beach, industrial settings with hot metal particles flying off grinders, etc.) where filters are useful for protecting the front of the lens, in catastrophic incidents such as yours they tend to be liabilities more often than not. A lens hood is normally better impact protection without any of the optical penalties of a flat glass filter.