MOD - tightening aperture ring – Fujinon XF 35mm F1.4 R lens

 First time I’ve done this mod to Fujinon XF 35mm F1.4 was Dec 20th 2013. I had spare time in the office, and required tools for the lens disassembly. I also had simple pencil with eraser laying on the table, which caught my attention and lead to this approach.

That time I’ve simply put the quarter piece of eraser to the lens, it happened to be reliable solution. Fujinon XF 35mm F1.4 lens served me well for few years with that improvement. Aperture ring was always more tight with the mod, and no more accidental F value switch. The person purchased that lens copy also liked the mod and decided to keep that enhancement.

Recently I’ve purchased this nice lens again to try it on Fujigilm X-Pro2 camera. The aperture ring is again too loose (by Fuji design for single finger operation), so today I’m doing a bit updated mod to increase aperture rotation effort using… same pencil eraser type : )

For this enhancement you will need:

  • precise tweezers
  • small screwdriver
  • hobby knife
  • adhesive tape

Fujinon XF 35mm F1.4 R partial disassembly

I’ve run complete Fuji XF 35mm F1.4 disassembly many times, but never had good time to make pictures. So spent more effort this time for better guide steps.

First step is to unscrew three black bolts of inner plastic cylinder around rear lens and pulling it out.

After that you need to unscrew four silver mount bolts, gently release lens contacts from the initial position, and then accurately remove silver mount ring. Do it carefully to prevent contacts wire damage.

Finally unscrew four black bolts of the ring with “Made in Japan” words, and pull it out.

Now it’s time to prepare piece of pensil eraser. For better durability I’ve got suggestion to wrap the eraser into tape while displaying this mod on one of Fuji X related forums (don’t remember the person, but if you are reading this article, thank you!). Today I’m using simple transparent tape.

The piece length is just a bit longer than eraser diameter. Later we will cut it in half. But first locate particular area on Fujinon XF 35mm F1.4 lens listed on picture:

The shape of this area perfectly fits the eraser diameter, so it will not jumps out of the position (remember, I’ve actively used XF 35mm F1.4 for years without issue). Gently insert the prepared wrapped piece there.

Now it’s time to check if you like the increased rotation effort. I typically use just exactly half of the eraser, it makes rotation effort similar to Fujinon XF 35mm F2 WR lens.

Then remove the eraser part, and cut it in half, so once inserted back it leaves about 1.5mm space for “Made in Japan” ring.

And then assemble the lens back in reverse guide order. Put on place “Made in Japan” ring, screw in four black bolts. It is a bit tricky to properly locate contacts into mount ring, so first do that, insert black plastic cylinder, and after that screw in four silver, and then three black bolts.

Please let me know if you have any questions on this DIY repair.

Here’s also another (and more simple) tightening aperture ring mod for Fujinon XF 14mm F2.8 lens. It also works flawlessly and helps to hold selected aperture value.