Snodge

If you wanted something a bit different, then the Lensbaby Velvet 85mm f/1.8 would certainly do that; otherwise there is a 135mm lens I've had my eye on - the MC APO Telezenitar 2.8/135 Lens, which is available new from the Lomography store. Ebay may have some older versions of the lens too. Otherwise I think Samyang is your only other choice really...

May I also suggest the Fujinon 55mm f/1.8 m42 lens? Also works great with a Lens Turbo II...

It's so hard to choose, but at the moment, I think my 3 are currently the Fuji 14mm f/2.8, 25mm f/1.8 Zonlai HD Discover, and Fuji 55mm f/1.8 m42 with Lens Turbo II

Fujinon 55mm f/1.8 on a Fuji X-T10 swimming by Hugh Jones, on Flickr

It kinda depends if you want to use a new manual focus lens (Samyang/Rokinon, Zonlai etc) or if you want to use an old lens for character. For the old lenses, as has been mentioned, the 50mm lenses are great - lots of variety both in price and manufacturers. The Industar 61-L/Z 50mm f/2.8 is nice and sharp, cheap, and comes with it's own extension tube to use for macro (below taken with the lens on a Canon body before I got the Fuji!): butterfly by Hugh Jones, on Flickr

If you can live with an f/2.8 lens, the Industar-61 L/Z is a nice lens that also comes with it's own extension tube for macro; they're not expensive but they have great image quality and very good sharpness. At 50mm it would do well at the shorter end of the portrait range. If you want something a bit longer, there's the reasonably affordable Helios 40-2 which is an 85mm f/1.5 lens that can have a swirly bokeh effect in some situations. The Jupiter 9 at f/2.0 may be a cheaper and lighter alternative. If you use a focal reducer (I use the very good Lens Turbo II) then you can also look at the myriad of 135mm lenses too, of which there are plenty in m42 mount. I've got a Sankyo Kohki Komura 135mm f/2.8 lens that while has low contrast renders very nicely indeed...

If you need 13 or 16 stops, the circular Formatt Hitech iRND filters are the way to go, no colour cast either...

I've used m42 lenses adapted to my Canon, and then when I got my X-T10, I used them with that too - at first because I didn't have any Fuji lenses, and now even with Fuji lenses, I use them because they are fun, and they have their own look and character which seems to be diminished with modern lenses that seem to seek sharpness as the defining characteristic. I use a Lens Turbo II for Canon EF mount (I have a Meyer Optik Somnium 85mm f/1.5 lens in EF mount) and use m42->EF to mount the old m42 lenses from ebay. At the moment, the MIR-24 35mm f/2 and Fuji 55mm f/1.8 lenses are my favourite...

I use adapted lenses as much, if not more on my X-T10 than I do than using Fuji lenses. It suits me, and I like the look of the images from some of the old lenses. For me, it's fun, so I keep doing it! As for resources, mflenses dot com is dedicated to old lenses and is interesting to look through, especially if you want to find out about a specific lens...

I got an X-T10 during black Friday in 2015, with no Fuji lenses. I found I was using it more with adapted m42 lenses than I was using my Canon 5D3, so after about 11 months, I got rid of my Canon gear as I just wasn't using it. I've got a couple of Fuji lenses as well now, but I liked the Fuji body before liking the Fuji lenses!

I also have the 14mm Fuji prime - it's one of the few lenses that works perfectly for infrared images. It's light and sharp and vignetting and distortion are very well controlled.

I picked a Zeiss up second hand and I'm happy with it, but I've never tried the Fuji 35mm. I think either would be fine, I'd just go with which ever is cheapest...

Ken Rockwell... the Donald Trump of the photography world...

I use a MIR-24M on my Lens Turbo II - it renders nicely, goes down to f/2 and is generally cheaper than the Zeiss lenses...

Ah! I did some looking into lenses that can be used for infrared photography, and the 14mm prime works great!