Disassembly - XF 50-140mm rear area

[yukosteel]

I had a need to clean up rear glass area of XF 50-140mm 2.8. Usually I don't spend time on making pictures, but Fuji lens deserve that, so make few shots to show you how this great lens look inside. It's engineered with very high quality.

 

XF 50-140mm mount ring and rubber sealing

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XF 50-140mm with mount ring removed, there are four brass shims firmly attached to internal metal cylinder

 

XF 50-140mm - white sealing o-ring around rear body lement

 

[yukosteel]

XF 50-140mm - view to the main board. There are 6 connectors need to be gently decoupled first.

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XF 50-140mm - main board removed. Three smaller silver screws hold rear lens group on place

 

 

XF 50-140mm - rear lens group module

 

 

XF 50-140mm - next optical module that is connected with at least four springs and freely moves perpendicularly to optical axis. There are electromagnets that control this module.

[quincy]

Cool, thanks for taking the time to make the pictures and post them!

Is the rear lens group adjustable somehow?

[Aswald]

You crazy man! Thanks for sharing.

 

How did the dust get in?

Edited April 10, 2016 by Aswald

[yukosteel]

It looks like the rear group module frame is just firmly attached to the metal cylinder. I think it can be micro-adjusted by putting different tension to each of 3 screws, so during the assembly I've put special attention to tighten all 3 screw equally. After the assembly the lens is still razor sharp wide open with equal good sharpness in the corners, so that module sits right on it's place.

 

I think for this 50-140mm lens the weakest area where dust may come in - is the mount. Then dust can travel further over the time.

In my sample the dust appeared because someone disassembled this XF 50-140mm before - I noticed slightly damaged screws.

I think that first disassembly is made by skilled person, but in a slightly dusty environment. I even found one cats hair inside : )

[DIS Ottawa]

You are much braver than I am;  I would never attempt something like this.

[yukosteel]

It's psychologically much easier to start with badly broken lens : ) Once you do that many times, disassembly converts to interesting activity, especially when you don't have any guide.

Some steps can be only done in lab, because they require further optic re-alignment on precise equipment, so I just avoid such things if possible.

I only removed 14 screws, and the most tricky part was to gently decouple electronic contacts - they are very fragile.

 

Before disassembly of any highly expensive gear just imagine that it is already ruined to zero value. It will help a lot to stay calm, confident and focused during the process.

Edited April 11, 2016 by yukosteel

[DIS Ottawa]

I'm sure that's true, but if I ever need lens repair, I suspect I'll send it to Fuji.  I've never been very handy; I worked in international relations where I didn't need superior hand coordination.  Just the ability to speak for a long time without saying much of importance.

[Aswald]

It looks like the rear group module frame is just firmly attached to the metal cylinder. I think it can be micro-adjusted by putting different tension to each of 3 screws, so during the assembly I've put special attention to tighten all 3 screw equally. After the assembly the lens is still razor sharp wide open with equal good sharpness in the corners, so that module sits right on it's place.

 

I think for this 50-140mm lens the weakest area where dust may come in - is the mount. Then dust can travel further over the time.

In my sample the dust appeared because someone disassembled this XF 50-140mm before - I noticed slightly damaged screws.

I think that first disassembly is made by skilled person, but in a slightly dusty environment. I even found one cats hair inside : )

 

 Thankfully it's just one hair!

[yukosteel]

Yeah, that hair was on the wall, not on the glass, I hope no more left inside : )

There are some other dust left. To get into that areas requires much more time than just few hours to go with more serious disassembly.

But that dust particles are even not in the image frame, and just too little to affect anything. So I'll just keep that as is.

[Fiddlergene]

I had to disassemble the 16-55 lens for the same problem. After I cleaned it up, I figured out a way to re-assemble the lens using one less screw.

[yukosteel]

Wow, 16-55 - that's another very interesting Fuji beast lens.

One extra screw ? If it has large thread step I'd not worry, but if it's frequent thread - probably that screw should hold important metal part ?

[Aswald]

Hahaha....one less screw. I'd probably lose sleep over that! I'm just ocd.

 

The only fujinon lens I disassembled (rear mount & element) was the xf18. Unforunately, it was dusty again in no time....

[yukosteel]

I keep discovering more details on XF 50-140mm disassembly. Found these nice pics on DPreview (by Barney Britton) :

 

Fuji XF 50-14mm, cut in half

 

 

Fuji XF 16-50mm, cut in half

 

 

Thank you Google ! : ) Search by picture link works great, found 2000x1500 size for 50-140mm 2.8 - that's something more reliable for disassembly analysis : )

https://s-media-cache-ak0.pinimg.com/originals/6e/8b/b5/6e8bb549474f353c471cdbfac06120f5.jpg

Edited April 13, 2016 by yukosteel

[Aswald]

I took this during it's launch with my iphone then. Not too clear but you can see some. I can send you the full res file if you like.

 

 

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[yukosteel]

Wow! It's much better shot for understanding how ale metal parts are connected, thank you Aswald!

 

Looks like it's a prototype, I see white plastic simulation of Aperture Module there : ) It's very interesting to see Focus Module cut differently here, and that it moves as well during zoom. Looks like your shot is taken for 50mm, while DPreview shot is for 140mm.

 

Some legend here:

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Edited April 16, 2016 by yukosteel

[Ian Sliney]

Hi Everyone,

Has anyone been able to tear down the from end of this lens? I dropped mine yesterday, and now the focus ring is slightly jammed and the autofocus cannot function properly. Looks like the part of the barrel just in from of the focus ring is stopping the manual focus ring from moving......

 

Any advice would be appreciated. I've had the lens less than a week..... :(

[yukosteel]

From what you describe it looks that there is more damage inside than just the manual focus ring, because this lens has focus-by-wire. It means there are no mechanical interaction of focus ring and autofocus, so that ring can not physically stop autofocus.

If autofocus does not work, it may be the focusing module is physically jammed (glass elements 9-11 on the picture above). It will be extremely complex disassembly process to get into the core of the lens. It may be also electronic problem, though in that case I'd expect lens to show any error to camera. I'd suggest to check first what would be Fuji repair cost as it doesn't look trivial problem to solve.

If the disassembly is the only option you can consider, then I'll try to help you with steps.

[yukosteel]

XF 50-140mm F2.8 has thin metal plate with lens marking that need to be removed first, it sits on four thin adhesive tape pieces.

Once removed there is a plastic ring under it that need to be unscrewed CCW. It is secured with glue in three points I can't try it on my current lens sample because it is still under warranty. Though under that plastic ring I'd expect to see bolts that are securing filter thread ring and front lens module.

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[lleo]

On 4/11/2016 at 3:42 AM, DIS Ottawa said:

Just the ability to speak for a long time without saying much of importance.

😄 lmao

[mcorona]

Hey just did the same with this lens that had a strand of something in the back element. Thanks for the inspiration. 

 

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Edited July 10, 2020 by mcorona

[yukosteel]

On 7/10/2020 at 4:41 PM, mcorona said:

Hey just did the same with this lens that had a strand of something in the back element. Thanks for the inspiration. 

Awesome! : ) Glad you managed to go further with disassembly. Great effort! Thanks for sharing your results.