Disassembly – Fujinon XF 18-55mm F2.8-4 OIS lens

I’ve recently read post on Fuji X forum about water damaged Fujinon XF 18-55mm F2.8-4 lens. Owner accidentally dropped it into the pond. It got submerged for seconds but water quickly entered inner areas leaving lots of dirt on glass surfaces. I’ve offered exploratory disassembly with a purpose of checking lens mechanics and try to clean accessible glass areas. Today I received that lens from Canada and partially disassembled it.

Dirt under the glass looks really bad, but fortunately lens owner did a great job disconnecting power and drying lens out for few days. I don’t see any mold or fungus yet – that is a good sign.

Disassembly steps

First step of frontal disassembly of Fujinon XF 18-55mm F2.8-4 lens is – accurately removing metal nameplate. It’s made of very thin metal so easy to deform, extra care is required.

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After thin nameplate is removed, I’m unscrewing four small silver bolts. It’s a joy to disassemble using JIS screwdrivers I’ve recently ordered from Japan.

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Then remove the plastic ring. You will see four black bolts and three silver calibrating bolts. Looks like this Fujinon XF 18-55mm lens sample has front lens module strongly secured with factory glue. So there is no risk of optical misalignment after reassembly. Accurately unscrew 3 silver bolts first, then unscrew all 4 black bolts.

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Now slowly lift up front lens frame accurately – there are three springs on the sides that are serving for Fuji factory lens calibration. Accurately remove them. Pay attention to tiny brass nuts marked with green arrows, they may fall out, but need to be put back during assembly.

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The front optical module frame contains two glass element. The dirt was on the inner glass surface of the second element, so I’ve accurately cleaned it with moisturized tissue then dried out and double cleaned with dry tissue.

If you check official Fujinon optical design, 1st and 2nd glass elements sit inside front module frame. On two pictures below you see front surface of 3rd glass element. When Fujinon XF 18-55mm lens is zoomed in/out – 2nd and 3rd element come very close at 18mm, and move far from each other at 55mm. So the space area between these two glass surfaces is collecting most of dust and dirt because air is flowing inside large space of zoom chamber.

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Luckily there are no much water went inside and most surfaces from the front area are relatively clean. It’s time to clean 3rd glass surface, then assemble front area back.

If you have dirt between 1st and 2nd glass elements – module glass can be removed from the frame after unscrewing securing ring CCW (around front of 1st element) using spanner wrench. I had to do that to remove some dirt under the frame borders. IMPORTANT: memorize radial position of each glass element before extraction to put it back in exact place, otherwise optical alignment may shift and cause IQ degradation. I’m using red marker to add line on frame and edge of glass, so later I put glass precisely positioned (but make sure you don’t wipe out that mark during glass cleaning). I learned that trick from disassembling many other brand lens noticing that repair persons sometimes left calibrating marks on optical surface edges during their repair/cleaning. You can check how it’s done when removing front glass in Fujinon XF 100-400mm lens.

After that I’m exploring rear lens area. I’ve wiped out most dirt from the rear glass surface, what you see is just cleaning moisture. Though there is some dirt under rear element. I’m initially unscrewing three black bolts and removing plastic ring.

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After that unscrewing four silver bolts and accurately removing mount ring. Then you need to unscrew three black bolts marked with red arrows and accurately pull out frame holding rear glass element.

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Other glass surfaces also have noticeable water drying marks, however it’s extremely hard to proceed with further disassembly due to lots of factory glued components, so I’ve decided to stop at this point. Remaining dirt should not significantly affect optical performance, which I’ll test later.

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It’s great to see that electronics is not impacted, it looks clean and I don’t see any water damage.

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After re-assembly lens looks close to new.

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Of course if you look through the lens on the light source – there will be some small dried water areas on the glass, but that is not affecting image details. Here’s the set of JIS screwdrivers taken on 18mm and on 55mm (100% crop of 1400px central area, noise is due to high ISO)

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It’s great Fujinon XF lens, I like to see that it survived challenging water impact and all electronics works likes new – focus is quick, OIS works great, picture is sharp after optics is cleaned. Fuji engineers did a great job adding some protection preventing the water spreading too far and allowing lens to keep operating after some maintenance.

Lens test shots

Luckily it was sunny day, so I’ve took numerous shots with cleaned Fujinon XF 18-55mm F2.8-4 on Fujifilm X-E2s camera.

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100% crop

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100% crop of Mt Rainier shot through the office window (so far distance, atmosphere and window glass are reducing details)

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The lens performs great, and it’s a joy to use XF 18-55mm zoom range.

Conclusions

This disassembly shows that it is relatively easy to clean Fujinon XF 18-55 F2.8-4 lens from the internal dust that may collect over time under front lens module (which is typical for many zoom lens). Looks like Fuji factory engineers are fine adjusting front module position first using spring loaded bolts, and after that gluing calibrating frame in secure position. It means that front module removal for cleaning does not cause optical misalignment, and I’m glad to see that.

18 comments

  1. Thank you for the interesting and informative post!

    Do you have any advice for how to remove the metal nameplate on the front of the lens without damaging it or scratching the adjacent glass?

    Thanks.

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  2. Hello, thank you very much! I want to clean my 18-55mm XF lens because it has fungus inside the front element lens. I’ve contacted a fuji authorized service center but they might charge it from $100-200! Do you have a video of how you done this? I’m worried about the springs especially when you said this –
    Now pull up front lens frame up accurately – there are three springs on the sides that are serving for Fuji factory lens calibration.

    Please help. Thanks!

    Liked by 1 person

    • Hello, and thanks for interesting question!
      Most likely the fungus is located behind the whole front glass module on the surface of second glass element (see the official Fuji X optical design: https://fujifilm-x.com/en-us/products/lenses/xf18-55mmf28-4-r-lm-ois/specifications/).
      It means that you can try to remove that front module first, and clean rear surface of second glass element. Do not worry about springs, just be aware of them. If you keep lens positioned like on picture and just slowly lift up front module – springs will remain on place. Just lift up front module, and then one by one pull out each spring – that is it.
      Let me know if you have further questions.

      Yuri

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    • I’ve just updated that article part with more details, so please read. There is a chance that fungus may spread between 1st and 2nd element. In this case you may need to use spanner wrench to extract the glass, and it’s more challenging procedure. So inspect the surface of 2nd glass element first, maybe all fungus is there.

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  3. Thank you very much for this article!
    I dropped the XF 18-55 and the barrel is slightly bent now, it’s hard to zoom out to 18mm now, do you have an idea if it’s easy to fix? Everything works, AF, OIS, but the front lens is tilted now and I’d like to attempt to bent it back.
    Thanks!

    Liked by 1 person

    • You are welcome!
      I’d be good to see pictures of damaged area to give you more precise hints.
      Generally saying it’s not easy to correct the distorted area without complete disassembly of that cylinder. Though if distortion is not huge, you can partially correct shape, but that still requires quite precise and accurate action to not damage other parts.
      For example, if the damage is in the middle side of protruding cylinder, you may partially disassemble lens like listed in the article, then lay the lens on the side and put wooden slab under the damaged cylinder to make damaged area lay on the wood. Then you can use rounded wood stick to accurately apply pressure from the inner side of the cylinder wall to correct the damaged area, but that requires attention not to press on inner optics or other parts. I don’t have XF 18-55 lens anymore to check if that cylinder is made of metal or plastic.
      Feel free to email me lens pictures to yukosteel@gmail.com, so I can give you better recommendations.

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    • Hi DP, thanks for interesting quesitons.
      It looks to me that replacing that frame completely will require almost complete disassembly of lens, which will involve lots of very accurate work on disconnecting ribbon cables and detaching them from the frame surfaces. I didn’t open 18-55mm so deep, and can’t say if there are more technical challenges there.
      What I’d try to do in this case is to disassemble mount area and remove the rear ring with OIS switch (need to be accurately disconnected from board during or before removal). Then I’d analyze the area and see if that two cylinders can be glued back to the place. After that I’d check if there is a space and possibility to enforce their position by drilling surrounding frame and inserting metal post. Anyway it is also requires quite an effort. If you try to do that – send me the pictures with questions, will be glad to help.

      Liked by 1 person

      • Hmm… your answer gives me a pause. I will try to do what you suggest in the second half of your response — explore options to glue or join the two parts. May be 3d print something in which the screws go and which can somehow be attached to the cylinder. Thank you!

        Liked by 1 person

        • If you take a closer look – Fuji are making that frame with brass nuts inside of that plastic cylinders.
          Fortunately there are few other bolts that are securing rear plastic ring to the frame, so another option would be to make a metal plate bracket to be capture by neighbor bolt, and help to secure mount bolt cylinder.

          When attempting disassembly, please point attention to all ribbon cables. I don’t know if you need to pull out rear lens frame first like I did to access ribbon cable connector of OIS external switch, or if it is accessible underneath the plastic shell ring – you need to discover that area and take gentle movements when removing shell ring.

          Also – take tons of pictures at every step – that helps to understand how to assemble things back. I can also give you a hint by looking at pictures. Feel free to email to yukosteel@gmail.com

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