MOD - Manual focus conversion – Fujinon XF 27mm F2.8 lens

Finally found time and modified electronically dead Fujinon XF 27mm F2.8 lens to manual focus lens with constant F2.8 aperture.

First I removed all electronic parts, AF and aperture drives, cables, light sensors. After that I’ve cut side area under the focus ring and attached metal wire to the inner focusing cylinder.

Lens outer focus ring catches that wire and now this XF 27mm F2.8 lens can be used in fully manual mode with true manual focus.

Of course aperture can’t be controlled and remains F2.8 which works fine for me, I used to take shots at F2.8 anyway with this tiny pancake lens.

There is quite large space area where autofocus drive and gears transmissions sit, I only had to cut thin slot in plastic frame border under focus ring and also cut few internal plastic pins. Rotation angle from infinity to minimal focus distance nicely fits there. I’m using metal spring that firmly holds the inner focus cylinder and connects to focus ring through the cut slot.

After mod lens weights 68 grams. I may add later focusing distance scale and aperture control lever in the lens front area, or alternatively add external aperture module.

For now I’m just using lens with aperture module completely removed. Looks like optical performance is not affected. Sure thing camera doesn’t know anymore that it’s Fuji XF 27mm F2.8 so no any JPEG auto corrections applied. Focus is not as pleasant as with helicoid rotation, but quite comfortable for quick manual focusing.

100% crop of above image

I’ve ordered aperture module from Hong Kong with 12 blades and 1.5-23mm hole range which is 37mm wide. It should nicely fit into front of the lens without increasing its size. I may also consider make it detachable due to using lower apertures are rare cases.

Focus distance scale

One of benefits having real manual focus ring on Fuji XF 27mm F2.8 – ability to add physical scale of the focus distance. I could do it more precise though for the prototype it works as is. I’ve cut strip of black vinyl film and painted marks with silver marker in following order (in meters) : 0.27, 0.3, 0.35, 0.4, 0.5, 0.6, 0.7, 0.8, 1, 1.5, 5, “infinity”.

Fuji XF 27mm F2.8 is a “pancake” lens with very little space on the body side, so I can’t fit all mark numbers there, so added just few. Vertical line on the focus ring indicates focus current position (focused to 1m distance). With constant F2.8 there are no need to add DOF scale on focus ring, since it will be just two nearest lines near vertical mark. Later I may add DOF if I manage to make aperture manually controlled.

I often like to take close-up shots and its very useful to know what is selected focus distance. Shot below is taken from 0.3m. You may notice barrel optical distortion in image border – camera don’t know anymore it is XF 27mm F2.8 and does not auto-correct distortions, its good to remember for shots where distortion influence is not welcome.

Focus ring maintenance

Direct manual focus mod is increasing forces applied to focus ring while rotated. So it may require lubrication after some time. Fortunately for the lens without electronics inside removing just focus ring is very easy. First step is to take out lens naming sticker.

Next step is to unscrew bolts listed on picture below and remove the securing ring. Make sure focus ring remains on it’s position. At this step you can clean and lubricate top inner edge of focus ring, opposite side of removed securing ring and velvet strip in the inner edge of securing ring.

NOTE: this step can be also done on fully functional Fuji XF 27mm F2.8 lens.

Final step is easy on XF 27mm F2.8 without electronic parts. But it shold be performed very carefully on non-modified XF 27mm F2.8 lens . It is a bit tricky to remove focus ring from the front side because in regular XF 27mm the opto-isolator sensors are catching inner pins of focus ring. One smart member of fujix-forum thirtythreeforty  just reported that it’s possible to remove focus ring “The focus ring actually lifts clear of the sensors – you just have to pick it up at an angle starting from the opposite side. Going back together is not hard either, just carefully slide the optical teeth into the correct position and lower the ring, using no force of course.” (Thank you thirtythreeforty for sharing your useful experience!) You can find more details, pictures and video in related arcticle: Write-up: Cleaning the focus ring on the XF 27mm

However with modified lens sample opto-isolator sensors are no more there, so focus ring will easily come off. There is also silicone ring under focus ring – I keep it there as it’s nicely dampening focus ring rotation (without that ring focus rotation is too loose). I typically use grease for plastic gears in such case to lubricate all friction areas.