I received the
Fotasy Pro Pentax DA K Mount lens to Fujifilm FX Mount Camera Adapter today. ($20 on Amazon)
Attaching the lens to the adapter and the adapter to my X-T100 body is very firm. No looseness, and if anything, a bit tight.
I checked out two lenses today: DA 10-17 FE and DA 16-85. The former is the one I was planning to use with some regularity. The latter was used as part of a comparison using the lenses on the Fuji and on my K-3.
The adapter adds about 3cm to the overall length of the lens. It's still rather compact compared to putting the lens on the K-3, but the adapter and DA 10-17 weigh about as much as X-T100 and the 15-45 kit lens!
I used the menu (Shooting Menu #4) to "shoot without lens" and set the MF Assist to Peak > Red (high). You can also input a specific focal length. There is no IBIS, but it is a handy way to set an odd number to identify a lens. (E.g., I set it to 49mm to designate that I was using the DA 16-85.)
As for shooting, I moved the adapter all the way to the Open position to manage focussing. The peak indicators work well, better on the LCD but also well enough in the EVF. The best way I found was to use the EVF and the magnification feature. With this, I was able to nail focus quite well.
The trick, however, (which will require more experimenting), is that you're just guessing when you try to stop down the lens using the adapter ring. It appears that it stops it down very quickly. I.e., just a tiny fraction of a turn probably moved the DA 16-85 from wide open to f8. (I'm guesstimating based on the shutter speeds and ISOs when comparing the same shot using the Fuji and the K-3.)
If anyone knows of a better way of managing the f-stop, I'd appreciate knowing.
As for the images...
The X-T100 did as good and usually better than the K-3 in almost all my tests. And that's with me shooting at wide open and otherwise unknown f-stops. In line w/ its reputation, the Fuji JPGs are excellent with more clarity and pop than the in-camera JPGs of the K-3. After some typical, light processing of the RAF and DNG files (setting levels, sharpening), the Fuji pics still just looked a little better. If I understand things correctly, the ~40MB RAF files are uncompressed RAW files and the ~30MB DNG files are compressed, but there seems to be lots more detail in the images.
I am not giving up on my K-3, however.
- I was able to shoot at 85mm in decent light without motion blur on the Fuji. I don't know how much of a longer telephoto I can shoot handheld without image stabilization.
- There is a difference in noise in the images. I'm having trouble saying which one is less noticeable or easier to clean up, but my sense is that the K-3 will do better in low light and higher ISOs.
- The K-3 and DA 16-85 is weather resistant, and that's important at times.
- While I've figured out ways to get geotagging data on my K-3 images (using a GPX file), the geotagging on the Fuji using the Bluetooth on my phone is proving to be excellent.
In any case, putting my Pentax lenses on the X-T100 is going to work out very well, I think. I still want to see how things go with longer lenses and some of my older lenses w/ aperture rings so that I don't need to use the aperture control on the adapter. And as I mentioned above, if anyone knows a good way to gauge the aperture settings with the Fotasy adapter, I'd be grateful.