These two cameras herald a new age for 44x33 medium format photography by putting a 44x33 sensor in a mirrorless body with the benefits that go with it. As others have said, while both of these cameras share a similar sensor size, thats where the similarities end. Beyond that, they are so different cameras, its really fascinating to see how wildly different choice these manufacturers have made.
In my opinion the X1D is the more beautiful camera both to look at and to hold. While visual aesthetics can be disregarded as inconsequential to making photographs, the comfort and feel of a camera in hand can make a different when a camera is handheld for extended periods of time.
The GFX in contrast looks like it was flogged by the ugly stick. This photo is actually the most pleasing angle, I won't bother with a shot of the back. I also have the EVF tilt adaptor and the first time I attached that, I had to laugh at how ridiculous the set up looked. The tilt adaptor does work well though if one needs the ability. I also realized that for my landscape photography I would likely just leave the EVF at home and use the flip screen which is very bright and sharp, thus saving weight. I wouldn't worry about glare from the sun as I typically do my landscape photography at dawn or dusk.
Body and Handling
Many others have already made many observations and comments on this. The GFX is bigger and a little heavier. The lenses have more volume but I don't think they are/will be much heavier than the XCD lenses. Its hard to tell since the lenses for the two systems have no real overlap today.
I generally find changing settings faster on the GFX and have observed that with the X1D if I rotate the dial fast, the settings don't change to keep up.
Shutter lag on both bodies seem similar as does blackout time and both are slower than a Leica S or SL.
My workflow for raw files involves using Adobe Lightroom and while it may not extract the fullest from the files of each of these cameras, to me the workflow overhead of introducing Phocus or SilkyPix is not worth it. That said, I did a quick comparison of the colors I get from the X1D files in Phocus vs. Lightroom and they are roughly on par, especially when switching Lightroom to using the "Embedded" camera calibration profile. I'm guessing Hasselblad does a good of embedding a good color profile and making it easy for third party software to read.
My summary of color is that I love what I get from the X1D in Lightroom and very much dislike what I get from the GFX. I don't think this is entirely the fault of the GFX but rather the combination of file produced and raw converter. Conversely, I love the colors of the GFX JPEG files and in many cases found myself just using the JPG. One advantage the GFX holds over the X1D is that it can record RAW to one card and high resolution, low compression JPG to the second, and both card slots are UHS. As of March 2017, the X1D doesn't allow writing RAW and JPEG to separate cards.
X1D, 90mm, f/3.2, 1/180s, ISO 12800, mixed lighting, handheld I don't have fancy color chart tests, but qualitatively, the X1D colors remind me a lot of the Leica S, which I've always found pleasing. Skin tones are very natural, even at high ISO.
<more to come>
I haven't done actual measurements, I will likely capture a dataset to submit to Bill Claff's excellent site Photons to Photos.
One quick measure I made is to visual read noise, by taking an image with the lens cap on, fastest shutter speed, lowest ISO. The resulting file was then heavily lifted (Exposure +5, Shadows +100, Whites +72, Blacks +100) in Lightroom to see if there was any pattern or the structure to the noise. Obviously no one will ever apply these kinds of adjustments, this is purely for visualization purposes.
The most interesting thing to me at this point is the circular pattern to the GFX file, I wonder if that comes from some lens correction profile automatically applied or something else. Also interesting is the slight bit of amp glow from the bottom of the frame on the GFX.
Update from May 2017:
Hasselblad support reached out to me after finding this post and offered to exchange my X1D for a new replacement. Their engineers thought that the patterning seen in the X1D file was abnormal and that I had a pre-production body. My replacement body arrived recently and I did the same test and found that the patterning is no longer there:
In short both cameras have great high ISO performance and I'm happy with the performance of either. The GFX however exposes less light than the X1D at the same ISO. The difference seems to be 1/3 stop or less. I compared the GFX and X1D images in Irident and found that the files are much closer there. So I don't think there is an issue with the GFX but rather its an issue of the difference in tone curve applied by Lightroom as a part of its profiles vs. Lightroom using the embedded profile for the X1D. I compared the output of the GFX files from Irident to that in Lightroom and there also they are very similar (so again I doubt there is a fundamental sensor difference here). Those interested in the differences can see them here:
GFX, ISO 6400, crop X1D, ISO 6400, crop The X1D image is clearly brighter, again not sure if this is because of the tone curve Lightroom applies or if the GFX file truly was under exposed in spite of being the same aperture, shutter speed and ISO. The noise levels look similar to me.
GFX, ISO 12800, crop X1D, ISO 12800, crop The ISO 12800 images are a bit different. For the GFX its purely a digital gain and the file takes on a strange green tint. However, on an absolute noise level, I'm not sure they are that different. Still if I need ISO 12800, I would reach for the X1D.
I am very interested in long exposure performance without dark frame subtraction for my landscape photography. Trapped in my office, I had to turn to my desk as the test subject. On a well exposed image, performance is identical, both cameras were very clean on my 4 minute exposure. From a UI perspective I love that both cameras allow me to set long exposure times right on the camera without the need for a cable release and bulb mode. Awesome to see camera manufacturers finally do this.
However I also did a long exposure / shadow pushing test just to see what the long exposure dynamic range was like.
GFX, 4 minute exposure, 5 stop push in Lightroom X1D, 4 minute exposure, 5 stop push in Lightroom This was very much a surprise for me. While no one will ever do a 5 stop push in the real world, this does indicate that for long exposures, you'll get cleaner shadows with the X1D.
The GFX is faster, more reliable and more flexible for autofocus with a lot more focus points, adjustable AF point size and a handy joystick to change AF points. However, I prefer the X1D for manual focus as the magnification factor is higher and the MF ring on the lens are adaptive to the rate at which you turn them, allowing very fine manual focus control. The one thing that I really wish the X1D had was a joystick to quickly move the focus zoom area or the focus point. Sadly, this is one of the few things that can't be fixed with just firmware.
Some folks have reported focus shift with some bodies/lenses. I decided to test this for myself and have details here. From my observations, I see some focus shift with the Fuji 32-64 shot at 64mm and the Hasselblad 90mm lenses. I'll have to use them more to be sure, but in both cases I don't think it will ruin images as even with the focus shift, the original point of focus remains acceptably sharp.
There are 3 lenses available for each system so far. In my early testing, all lenses appear superb. The GFX 32-64 zoom seems sharp wide open on the wide end, however the bokeh is not pleasing. I didn't expect this, but on the Fuji I'm becoming a fan of the 63mm f/2.8 lens, its light, has nice bokeh and is generally a pleasing lens. The 120mm macro is big, heavy but has superlative sharpness even at infinity and having image stabilization on a macro lens for medium format is pretty awesome.
On the X1D, I've been more drawn to the 45mm, though the 90mm also has very pleasing output.
Update from May 2017
Over the last couple of months of owning both systems, I've found that I reach for and use the X1D far more often than the GFX. The one exception is macro photography. The GFX 120 macro lens with stabilization is a fantastic kit for hand held macro photography.
However, for other types of photography I naturally tended to reach for the X1D. Upon reflecting on why I realized it came down to the simple UI, the lighter weight and profile of the camera, how it feels in the hand and the dramatically less time I spend in post processing with the X1D files. I have no interest in adapting third party lenses (a major advantage of the GFX) and since I have a Phase One IQ3 100 and technical camera for my landscape work, I'm covered there too.