The “FUJINON TELECONVERTER XF2X TC WR” is a high-performance teleconverter capable of multiplying the focal length of mounted lenses by two.
This gives the XF 50-140mm f/2.8 and effective focal length of 100-280mm f/5.6, or 152 to 427mm in 35mm equivalence, and the XF 100-400mm f/4.5-5.6 reaches all the way out to 200-800mm f/9-11, which is 305 to 1,219mm in 35mm.
That quite a bit of a slow down in aperture, but over 1,200mm of reach is going to be tough to resist.
No Phase Detection
Also worth noting, we lose Phase Detection on the XF 100-400mm f/4.5-5.6 altogether with the XF 2X TC attached thanks to the reduction in aperture. That could pose a bit of a problem for things like early morning game park drives or bird photography outings when higher ISOs are already common. It will be interesting to see how this lens performs with the TCs attached.
Size and Weight
That extra reach also means extra size and weight with the new 2x weighing in at 170g, or 40g more than the 1.4x and measures twice as long at 30.2mm. I’ll be getting close to maxing out the height of my bag already, so be mindful of your max carry size before you place any preorders.
Edit: Jonas Rask already has one of his typically epic reviews up for the XF2X TC. Man, that guy is on fire these days.