Optically fantastic provided you correct the distortion. I’m talking about the WCL-X100 wide angle converter which converts the X100 23mm lens to a 19mm lens (which means it becomes a 28mm equivalent). The build quality of this converter is excellent. It just feels like a solid hunk of metal and glass, with construction matching the X100/X100S body/lens. As the WCL-X100 simply screws into the front of the X100/X100S lens, the focus and aperture rings are the ones on the “normal” lens. The WCL-X100 has no markings on it at all. It accepts 49mm filters, the same as the official Fujifilm filter adaptor, so the official lens hood can be used on the conversion lens. Optically, with one exception, this converter is very good. CA and fringing are almost non-existent. There is a little vignetting wide open that disappears as you stop it down. In terms of sharpness, it’s pretty similar to the X100/S lens – average at F2 but becoming excellent past F4. Unfortunately there is some barrel distortion which you can correct in camera for jpegs, but a profile is required for RAW files. I would like to say thank you to “Hector” who uploaded a lens profile for this lens to Adobe Lens Profile Downloader. It seems to work well enough. I realise many of these shots need keystone correction, but in the absence of capture one support there is not a lot I can do. Autofocus speed seems to be very quick with the adaptor fitted. By way of an aside (and nothing really to do with the WCL-X100), I tried switching to continuous autofocus to see if that speeded up AF. It does, AF on the X100S is actually as fast as the E-M5 (no mean feet) in good light. Yes and no. The 28mm focal length is more challenging for street photography but does give you that little bit more to play with. I do prefer 35, but there are times when 28 is a definite preference. This is a really nice, well built piece of kit that is definitely worth getting if you plan to travel with your X100/S. The only downside (for me) is that it is relatively expensive and you need to tell the camera it is fitted.
Via Thomas Menk, lhotse