MOD - Exploring conversion of Fujinon XF 35mm F1.4

Fujinon XF 35mm F1.4 lens is a real gem in Fujinon line, the optic is outstanding. It’s one of the first developed Fuji X system lens. The AF is quite fast, but it is noisy and delaying camera operations. In many cases the real manual focus would work much better.

I’ve purchased used but fully working sample to disassemble and check if the lens can be converted to manual focus only. My point was to keep the electronic aperture controlled by camera, but disconnecting focus ring from the AF drive so I can control it manually.  Mechanically, the XF 35mm F1.4 has real focus ring right under the drive-driven outer manual focus ring. I’ve removed outer focus ring, disconnected the AF drive gear from the inner focus ring, and also lens contacts from camera. In such mode you can use true manual focus, and it’s moving quite smooth. I love how it works that way without using AF drive, completely silent. I enjoyed focusing that way on X-E2s, and wish I keep the lens modified if only it’s possible to operate the aperture.

Unfortunately the aperture is electronically controlled, so without lens contacts the lens will be constant F1.4.

I’ve tried XF 35mm F1.4 lens on camera with electronics connected, just removed the AF drive – then camera fails to start showing the lens error message.

I’ve also tried it with AF drive connected to electronics, just located it outside of the lens. In this case camera starts and electronic aperture got set to the value of aperture ring, but camera then tries to AF test lens and detects that AF is not focusing, then again the error message is shown to turn the camera off.

I wish there is a simple way to disable AF test on start, or to get manual control over the aperture, then I’d use converted XF 35mm F1.4 in pleasant fully manual focus mode without any electronics in it (and related camera delays and AF hunting in low light). But it is not possible without non-reversive modifications.

So the converting experiment failed, but I’ve got useful details about the XF 35mm F1.4 lens, and also ran the disassembly process many times. The lens is working perfect though after assembling everything back, and I used that as the opportunity to clean the glass and relubricate mechanics.