Targeted users
My impression is that Fuji brought out the X-Pro1 for high-end enthusiastic photographer (hence the "Pro" name and high price tag). If you know how aperture, speed, and ISO work together, and are willing to take time to compose a shot, then this camera will certainly suit you. If you are shooting fast moving objects (sports or even kids), then you are probably not going to like the X-Pro1 because of its slow autofocus and shutter lag (see AF discussion below). I've seen some reports from people who thought they were "ripped off" by Fuji after buying the X-Pro1. I can understand that, because this is not your typical point and shoot camera. Neither is it a DSLR replacement. It takes time to really understand the camera and get accommodated with this new style of shooting. It takes some effort to get the picture you want; it's not a point and click machine!Physical impressions
Overall the camera is well built, although the bottom paint is a bit fragile in my opinion. The first time I saw it, I thought it would be much heavier in hand. That is really a great surprise, as both the body and Fuji lenses I have (18mm ƒ/2.0 and 35mm ƒ/1.4) are very lightweight. My intention was mainly to use the X-Pro1 for travel photography, as I was tired of lugging around my Canon 450D and the heavy lenses on family trips. The change was very welcome!Shooting style
This is where I had to adapt myself most. Being used to optical viewfinders from DSLRs, I really wanted to get the same feeling in a smaller camera. There were numerous mirror less cameras, but most of them didn't have an optical viewfinder. I had long looked at the Fuji X100 and a friend let me try it. I really enjoyed it and almost ended up getting one. My major reluctance was that it had only one fixed focal length, and I didn't know if I could shoot like that. In the end, it was this friend who recommended I get the X-Pro1! The big innovation is the hybrid viewfinder: both optical and electronic. That means that you can either look through the optical viewfinder (OVF) like a DSLR, even though you don't actually look through the lens. You're just looking through a "hole" in the camera, with superimposed frame lines to show you the approximate frame the camera will shoot. These frame lines adapt when you change lenses; there is even a different magnifying glass that pops into the viewfinder when you switch between the 18mm and 35mm lenses. Very clever stuff, but I wonder how the thing will work when Fuji brings out zoom lenses. (Which are planned to come out later.)
A major drawback of the OVF is that you don't really see exactly what you will be shooting due to the slight difference of point of view between your eye and the camera's lens. This is called the parallax effect, and it's all the more pronounced the closer objects are to the camera. It's like putting one finger in front of your left eye: with both eyes you still see it, but if you close your left eye, it's gone.
Focusing with the OVF is also quite "unconventional". By that, I mean that you will not be sure where the camera focused, as there are no focus point confirmations. Instead, you can see two rectangles in the center of the frame which will light up green when the focus is acquired. The rectangle in the center is for the far distance focus, and the dashed rectangle a bit more on the right and down, is for the closer focus. If the camera acquires focus close to the camera (say your subject is about 1m away), then the right rectangle will light up. If the focus is at infinity, the center rectangle will light up. And if the subject is in between, the green rectangle will be somewhere between the 2. It's more complicated to explain than seeing it! But in any case, it does take some time to get used to it and understanding intuitively where the camera focused. It’s a bit like learning to switch gears in a manual car when you’ve only driven automatics.
The other way to shoot is through the electronic viewfinder (EVF). This means that you get a real live view of what the sensor is seeing being projected into the viewfinder. This is the most accurate way of shooting, and the mandatory way in macro mode. I personally don't like it too much, maybe because I'm not used to it, but I find that it strains my eye quite a bit. The refresh rate is not quick enough for my liking. If I need to use the live view, I actually prefer to use the back LCD for that.
If you want a more detailed explanation, I'd suggest reading this good article.
AutoFocus (AF)
AF is probably the area where the photographer has to adapt the most, coming from a DSLR world. On my Canon DSLR I use the * button to acquire focus on the central focus point and then recompose. This works fairly well, except at really shallow depth of field (low F values). The only time I really care about recomposing is when I shoot with my very fast prime (the Canon EF 50mm ƒ/1.4 lens) full open at ƒ/1.4. DSLRs use phase detection AF while the Fuji X-Pro1 uses contrast detection. This means that on the X-Pro1, ideally, you should focus on a contrasted area, say something changing from black to white. This works great with shadows for example. You can also make the AF area smaller or larger, which I found really useful. I've set it to a smaller than default size and for me, focus seems to work better. You can also change the placement of the focus point to very far places like the corners of the frame; something that is totally impossible with a DSLR. Focus on the X-Pro1 is acquired when you half press the shutter button or use the dedicated AF button when using manual focus mode. One of the major flaws of the camera in my opinion is not so much the time it takes to get correct focus, but the shutter lag after that focus acquisition. Sometimes the camera can take a long time to shoot the frame; it's not always the case and I'm not sure why this happens. It doesn’t seem to have anything to do with the buffer writing (I use a fast Sandisk Extreme Pro 95MB/s card). It seems more like an electronic lag with the light measuring and aperture blades closing and re-opening. Hopefully this will be fixed soon by a firmware upgrade. To avoid this lag, some people have suggested pressing the shutter button down firmly, avoiding the half way AF acquisition altogether.Image Quality (IQ)
This is where the Fuji X-Pro1 really shines! This is why I bought it in the first place. Even though the sensor is only an APS-C sized sensor, the picture quality can be compared to a full-frame sensor. Some people say it’s comparable to a Canon 5D Mk II. I don’t have a full frame camera so I can’t really compare, but it’s true the IQ is absolutely stunning. I am a big fan of shallow depth of field images, especially for portraits, with beautiful bokeh. This camera really convinced me on that point. You can see some examples of portraits shot wide open at the end (you can click on them to get bigger sizes). And I'm not even talking about high ISO pictures here, but they are absolutely amazing; ISO 3200 is perfectly useable.Using the Fuji X-Pro1 with other lenses
The beauty of this camera is that you can buy adapters for a lot of older legacy lenses. The purists will love the Leica M adapter, now officially available from Fuji. I bought a cheaper version on eBay (before Fuji’s came out) and got the chance to try some Leica lenses. I also bought the Canon EF mount adapter, but found it less desirable. Indeed, the EF (or EF-S) lenses don’t have an aperture ring adapter on them. This means that you will be shooting the lenses fully open (the lowest F number), which is not always good. Indeed, some lenses give poor image quality fully open. For example, my EF 50mm ƒ/1.4 lens is quite useless. It gives purple fringing and chromatic aberration to the image. For that reason I also purchased a Nikon F mount adapter as well as a cheap pancake lens (the Nikon Series E 50mm ƒ/1.8, see my other posts for more detail about that lens). This lens lets me adjust aperture directly on it, and it performs admirably well even fully open. It is totally incredible in fact; it must be one of the best quality/price ratio I’ve ever seen! One of the major negatives to using these legacy lenses is that you will lose AF. On the other hand, exposure metering still works flawlessly and the mysterious shutter lag is now gone. Adjusting focus manually is a bit difficult at first. Either you have excellent eyes and can do it fairly precisely with the back LCD, or you can see a 10x magnified image when you press the command dial. 10 x magnification is in fact huge for portraits. It works well with the 50mm lens, but with the 90mm I tried, you really need to have a steady hand, otherwise you’ll quickly feel sea sick! I wish Fuji would let us adjust the magnifying ratio by turning the command wheel while in magnification mode. Hopefully Fuji will also be adding focus peaking (check out this video to see focus peaking in action). Focus peaking would be really great, and make the manual focus process so much easier (even with Fuji’s own lenses).