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Canon 28-70mm f/2 smudge issue


Dear Canon Support Community,

I am writing to seek urgent assistance regarding an issue I have encountered with my Canon 28-70mm f/2 lens. In August of 2021, I noticed the presence of small smudge prints on the front element of the lens. It is important to note that the lens was in perfect condition the previous night, and I discovered the smudge prints when I woke up for a shoot. The smudges did not initially affect the images captured. However, this lens is crucial to my work as it serves as my primary lens for all my wedding shoots and personal projects.

Concerned about the smudges, I promptly took the lens to the Canon India Service center. Unfortunately, they immediately blamed me for scratching the lens surface, even though the lens was still under warranty at the time. Despite my insistence, they refused to accept the lens for further inspection to determine the cause of the issue. Their suggestion was to continue using the lens as it was not visibly affecting the images.

Now, fast forward to the present, the smudges on the lens have significantly increased in size and quantity. As a result, the quality of the images captured is visibly affected. I have attached pictures for your reference.

To my dismay, I have discovered that I am not the only person facing this issue. A quick search on various forums, including Reddit, reveals that at least five other individuals have experienced the exact same problem with the Canon 28-70mm f/2 lens. What is even more concerning is that none of the Canon Service team members have provided a definitive cause for this issue.

As a professional photographer and a loyal Canon customer for over a decade, I believe it is crucial to understand the root cause of the problem in order to prevent future occurrences and maintain trust in Canon's products and services. Has anyone in the community faced this issue? August 2021August 2021June 2023June 2023




Not applicable

Did the front of the lens get wet? I have heard of some of Canon lenses having issues with the coatings peeling if they got wet. I always use a clear filter on my lenses to keep fingerprints and moisture off of the lens front element.

Yes. When the issue happened there was moisture on the lens. 


I had a similar issue. I just learned to live with it as it doesn't affect the photos. Hopefully, you can get yours fixed or cleaned, whatever is needed.

Canon EOS T7; EF-S 18-55mm IS; EF 28-135mm IS; EF 75-300mm; Sigma 150-600mm DG

I got the front element fixed. They have sent the faulty front element to Japan to figure out why the issue happened. 

Not applicable

Is Canon covering the cost under warranty?

Greetings , 

I've never had the coating on a lens delaminate or degrade. I did have fungus once.  That was a teenager mistake.  Unfortunately, with an expensive Vivitar zoom.  Are these "smudges" on the inside or outside of the front element?  Has the coating delaminated?

If inside this is contamination, Canon didn't sell you the lens this way.  If outside then the lens experienced an impact, came into contact with something abrasive, or was exposed to something corrosive that has degraded the lens coating.  Moving forward I'd consider a clear lens filter at the very least.  A better recommendation for a professional who relies on his gear to earn a living is a CarePak.  Regardless of what happened or who is responsible.

Bay Area - CA

~R5 C ( ~RF Trinity, ~RF 100 Macro, ~RF 100~400, ~RF 100~500, +RF 1.4x TC, +Canon Control Ring, BG-R10

~DxO PhotoLab Elite ~DaVinci Resolve ~Windows11 Pro ~ImageClass MF644Cdw ~Pixel 8 ~CarePaks Are Worth It

Yeah, looks like the front element was exposed to some acidic or corrosive element that's continually eating away ay the coatings. 


"...  the front element was exposed to some acidic or corrosive  ..."  or impact of some kind.

I am agreeing with that. Something contacted the front of the lens. Who knows how you used this lens or where and under what conditions. We certainly don't. It is another good example for the use a clear protecto filter on expensive lenses. But that is closing the gate after the horse has fled!

EOS 1DX and 1D Mk IV and several lenses!


The fluorine coating on the windshield of the lens is damaged. And over time (in my opinion, fluorine is an external factor that causes the surface to deteriorate.) This situation spread over the surface of my soul..

Fluorine coating powder, water, etc. It prevents external factors from sticking to the surface. The user can guess what caused the coating to fail.

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