I would like to show you one of my favorites pictures taken with the Fuji XF100-400mm: A beautiful little owl spotted in Hoces del Río Duratón Natural Park in Segovia, Spain.
Fujifilm X-T1 XF100-400mmF4.5-5.6 R LM OIS WR ƒ/5.6 400.0 mm Shutter speed 1/20 ISO 200
I was shooting a 5D MKII and a 5D classic with a fairly large collection of L glass when I bought my first Fuji camera, the X-E1. The AF was horrible, the EVF had lag, and Lightroom couldn't even read the RAW files for quite some time so I had to shoot mostly jpeg. Needless to say, at that time the Fuji was more of a toy to me and I used the camera once in a while for fun. When the X-T1 was announced, I preordered it. Before I received it, I sold the 5D classic and ordered a 6D to replace it as a backup to my 5D MKII. Once the X-T1 arrived, I started using it a lot. It didn't feel quite ready to replace a DSLR, but it was so much closer than the X-E1. The firmware updates made the X-T1 into an entirely different camera. The way they transformed the camera is difficult to explain. Think of it like having a 5D MKII downloading the firmware (for free) and having a 5D MKIII. The AF performance difference was an incredible step up.
From my Canon setup, I was sold on FF sensors. I had a Rebel and a 50D and the sensors in them were fairly bad, and the focal lengths of the lenses just seemed off. Everything was better when I stepped up to the 5D. I was hoping Fuji would release their FF model too. The X-T1 began to change my thinking on this. I bought some of the Fuji prime lenses and was blown away by the quality. The images looked better than what my Canon L lenses produced. Last July I took the X-T1 and 56mm F/1.2 along with my 6D and 50mm F/1.2L on a portrait session and shot them side by side (shortly after firmware V4). This was the first time I ever used the Fuji to shoot any sort of portraits and I don't remember why I didn't at least test this before on a friend. I shot the Canon at F/2 and the Fuji at F/1.4 for many of the shots. I think the Fuji photos looked better overall.
Needless to say, I had sold the 5D MKII and some L lenses. I also have a 6D with less than 2000 shutter actuations on it. I was holding onto the 50mm F/1.2, the 135mm F/2, and and the 70-200mm F/2.8 because those were may favorite lenses. My X-Pro2 arrived late last week and I started to photograph the rest of the Canon gear for Craigslist. I do not see any loss of image quality or usability at this point with the Fuji; at least for me. I don't shoot with flashes often so the lack of a flash system hasn't bothered me. As Jackalized said above, the lens selection from Fuji helps with the equivalent factor. They created lenses with the APS-C sensor in mind for all the popular focal lengths. I never thought I'd say this, but FF no longer matters to me. If Fuji were to release one, I'd at least evaluate it. I'd probably be more interested in the MF camera that is rumored though. Overall, the Fuji cameras make shooting fun. You want to use the camera. This has been my experience over the last few years.
