It’s late in the afternoon and I am sitting at my desk casually culling images for upcoming posts when I suddenly get called out to the service room. I walk in to see Michelle and Paul Duclos standing around a plastic bag on the desk with strange looks on their faces and pointing at me to open it. As I pull the plastic off, I come to realize what has them taken aback. A sad sight. Placed in the bag was a Canon K35 zoom that was completely caked with mushy deteriorated foam the same texture and stickiness of a toasted marshmallow.
My first thought: This is going to make a great story. The second: I need gloves.
The Cause and Consequences
To be upfront about everything, there was no definitive explanation as to what happened with this lens. We can speculate that it occurred over the course of time because foam eventually degrades naturally, but that would also then imply that no one had opened up this lens’ case in years. That would be a sad reality. Of course it could have happened much quicker if the case was left somewhere where heat built up without any ventilation as that would have essentially baked the foam and melted it onto the lens body. What we do know is that the foam was old. The case the plastic bag-wrapped lens came to us in was in need of replacement even aside from it melting.
Look at this. Splinters from inside the case stuck to that mush. We get asked quite a bit about how to store lenses, what cases are good, dividers vs. foam, etc. etc. We have a conversation with Innerspace Cases further down in the article to answer some of those, but the immediate advice is check in on your lenses every once in a while so they don’t get like this.
The Before and After
Before our techs could get to cleaning the muck off, I had to snag some photos of it. This is where the gloves came in. Because the foam was essentially tar, it would cling to everything. Chunks of it would peel off of the lens, but there would be residue left behind. Photographing it was no easy process by myself.
Once in the hands of our techs, the real work began. Surprisingly, the optics were in decent shape. Aside from a slight adjustment, there wasn’t much that needed to be done internally. The work was contained to the exterior housing which was no easy task. Instead of soaking all of it, we meticulously peeled and cleaned it away to ensure every bit of residue was removed. Dissolving chemicals are useful, but you still have to be careful with them after all.
Under all that was a beautiful Canon K35 25-120mm T2.8 Macro Zoom that just needed a little bit of love. When it came out on the other side, it actually functioned and looked like a proper cine lens ready to work for years to come.
Proper Care & Maintenance
Now to answer some of the most asked questions about lens storage, we turned to our friends at Innerspace Cases.
Innerspace Cases is a fourth-generation, Los Angeles-based case manufacturer trusted by industry leaders worldwide. With over 100 years of experience, they specialize in designing and building custom cases for the motion picture and broadcast industries. From precision foam engineering to rugged, real-world-ready hardware, their solutions are built to protect the gear that powers production.
Enjoy the Q/A:
Frank Ramirez – What are the most common mistakes people make when choosing or using foam for storing high-end optics like cinema lenses?
Innerspace Cases – “Using the wrong foam ends up costing more in the long run.” Polyurethane foam may seem soft and protective, but it breaks down in heat and becomes sticky — a serious hazard for lenses. Pick-and-pluck foam is another issue: it sheds particles that can damage moving parts and glass. These low-cost solutions often lead to high-cost repairs.
Frank Ramirez – How does foam quality impact long-term protection against moisture, heat, and pressure?
Innerspace Cases – We use multi-density closed-cell polyethylene foam, which resists breakdown and absorbs shock. Each lens case also includes a built-in anti-moisture compartment for long-term protection against humidity and temperature swings.
Frank Ramirez – What’s the value of a custom foam fit vs. an off-the-shelf case?
Innerspace Cases – A precision fit eliminates shifting, cushions against drops, and keeps lenses secure. We’ve had clients report severe case impacts with zero lens damage — that’s the difference a custom fit makes.
Frank Ramirez – What features define a professional-grade cine lens case?
Innerspace Cases – Look for closed-cell, multi-density foam, reinforced case construction, a custom-cut interior, and moisture control features. At Innerspace, these are standard in every build.
Frank Ramirez – Best practices for storing lenses long-term?
Innerspace Cases – Avoid polyurethane foam. Always include desiccants, store cases in a dry, climate-controlled environment, and consider lining foam with velvet or microfiber to prevent residue transfer and extend the foam’s life.
Frank Ramirez – Recommended humidity levels for lens storage?
Innerspace Cases – Aim for 35–45% relative humidity. Our cases are designed to stabilize internal environments and can be paired with optional humidity indicators.
Frank Ramirez – Any techniques to extend the life of your custom foam?
Innerspace Cases – Minimal maintenance is required, but keeping foam clean and dry is key. For added protection, many clients wrap their lens cavities in velvet to eliminate foam-to-glass contact entirely.
Time To Pack It Up
At the end of the day, the importance of properly storing your equipment cannot be understated. Gear is a huge investment for everyone in the film industry so it should be treated as such. For regular maintenance trust us as your go-to shop for everything from cases to lens repair. Our expert techs and sales team will make sure you’re never trapped in a sticky situation.
Thank you, great job. I shot my first 35mm feature film, Dark Summer, distributed by Mel Gibson’s company Icon, on that Canon K35 25-120mm T2.8 Macro Zoom, mounted on a blimped Arri 2C, it was shot in SuperScope. I owned the camera and lens but sold it on after the film completed.
You can see screen grabs from the print and and production photos below:
https://www.charlesteton.com/-/galleries/dark-summer
Thank you for all your very interesting lens work.
Regards, Charles
how prewent from fungus