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Fujifilm X-Trans CMOS sensor

The XE-1 makes use of the same X-Trans sensor as the X-Pro1, which means using a non-standard filter pattern in front of the sensor. The result, according to Fujifilm, is minimal susceptibility to color moiré, which in turn allows the company to dispense with the anti-aliasing filter that's used by almost all other cameras. In principle, this means the X-E1 should be able to resolve more detail than Bayer-array cameras with a similar pixel count.

The color filter array

Almost all digital cameras use what it called a Bayer color filter array, named after the Kodak engineer who developed the pattern. Over the years it's proved to be an excellent way of capturing both color and detail in a scene. Essentially, it consists of a simple repeating pattern of four pixels, two of which are sensitive to green light, one to red and one to blue, in a square RGGB layout.

However, one problem with the Bayer array is its susceptibility to false color artifacts when faced with an image that contains finely-repeating patterns (such as textiles), caused essentially by interference between these patterns and the regular grid of photosites. This results in unsightly bands of color, and in most digital cameras is suppressed by the addition of an optical low pass (or 'anti-aliasing') filter in front of the sensor that blurs away the finest image detail. This reduces any moiré patterns, but with an inevitable loss of resolution.

Film never showed an analogous effect due to its random grain structure, and Fujifilm's engineers reasoned that modifying the sensors' color filter array to make it look more irregular would have a similar effect. The result is the X-Trans CMOS's 6x6 color filter array, with red, green and blue photosites on each row and column (diagrams courtesy of Fujifilm):

The common 2x2 'Bayer' pattern used in most digital cameras The 6x6 color filter array pattern of Fujifilm's X-Trans CMOS sensor

Use of an unconventional CFA is not without its complications, though; most obviously, it demands a completely different de-mosaicing algorithm for RAW conversion. Rather than simply re-calibrating the Bayer conversion processes they have refined over a decade or more, the developers had to start again from scratch. There's greater potential for conversion artifacts in areas of the image that might require special treatment. Despite Fujifilm's plans to work with third-party Raw processor makers, many popular converters still don't support the X-Pro1, which is a problem that extends to the X-E1.

In reviewing the X-Pro1 we found Adobe Camera Raw's conversion fell below the standards we'd usually expect of it, and the Fujifilm-provided conversion software seemed to have more trouble properly de-mosaicing the X-Trans filter array. This looked like it might limit the XE-1's options for Raw shooters. However, just before publication of this review, Adobe released a new version of ACR that addresses most of our concerns, with a better, more natural rendering of fine detail (see our Raw page for more, as well as our more detailed article, Adobe's Fujifilm X-Trans sensor processing tested).

All-electronic X mount

As the second camera to offer Fujifilm's X-mount, the X-E1 offers few surprises to anyone who's been following recent developments in mirrorless camera systems, being an all-electronic bayonet mount with ten contact pins for communication between the camera and lens. X-mount lenses have traditional-looking aperture and focus rings, but these have no direct mechanical coupling, and do nothing when the lens is dismounted from the camera.

The X-mount's claim to fame, though, is an extremely short flange distance (from mount surface to sensor) of 17.7mm - shorter even than Sony's E-mount for its NEX system. The lenses themselves feature unusually short backfocus distances from the rear element to the sensor, and use large rear elements to maximize the illumination of the corners of the frame. The diagram below supplied by Fujifilm) illustrates this principle, here showing a simulated view of the 18mm prime mounted on the X-Pro 1:

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Comments

Total comments: 12
BobFoster

I have had this camera for almost 3 weeks already and I also can’t figure out how to set the minimum shutter speed when using auto ISO, can you shed a light on that?

Thanks!

1 upvote
Menneisyys

I use the quick shortcut assigned to the Q (or Fn? The one next to the shutter button) button. There, you can quickly change the minimum shutter speed while using auto ISO.

0 upvotes
kreislauf

why was the X-E1 picture taken with a 35mm lens while MFT had the 50mm mounted and FF like A99 or 6D had 85mm???

1 upvote
Menneisyys

The 35mm F1.4 and the 60mm F2.4 Macro (the only two normal / short tele primes at the time of writing) are about equally sharp at f/5.6 and f/8 (see http://slrgear.com/reviews/showproduct.php/product/1487/cat/105 and http://slrgear.com/reviews/showproduct.php/product/1486/cat/105 ). In addition, the 35mm doesn't exhibit much field curvature, unlike, say, the latter-released 27mm/f2.8 pancake (more info on this problem: http://www.photozone.de/fuji_x/855-fuji27f28?start=1 )

0 upvotes
Menneisyys

(cont'd)

Finally, now that the absolutely stellar (see http://slrgear.com/reviews/showproduct.php/product/1674/cat/105 ) Fujinon XF 56mm f/1.2 R is out, non-macro people able to shell out the double the price generally prefer it to the old 60mm F2.4. (Of course, this may not have been a point in choosing the 35mm over the 60mm back then. Nevertheless, we are pretty lucky to have a studio shot demoing the field curvature / sharpness of prolly the most popular Fuji X prime, and not that of one that has since been overshadowed by a newly released one.)

0 upvotes
pscharles

continuing my post . . .

I understand why Fujifilm designed the lens rings with those slim grooves for stylistic reasons, but I find myself frequently turning the wrong one because they all feel the same. I'll get used to it, but a rubber ring on the zoom would help. Also, the zoom ring is stiff and those little grooves are slippery. Rubber would help the grip.

I would suggest turning off the image display as the default is 1.5 seconds. The image display clogs up the EVF for 1.5 seconds making it impractical to follow action. It's in the menu under setup screen 2.

1 upvote
pscharles

Had mine a short while, purchased in part due to this review.

A couple things worth mentioning in terms of this review. The exposure compensation dial on my camera has a very firm detent so there's no chance of an inadvertent movement of the dial. I've loaded body firmware 2.0 and 18-55mm lens firmware 3.0. According to Fujifilm, these updates are supposed to address a number of issues, including the slower focusing. I find the camera/lens focus speed to be quite good with this update in place.

0 upvotes
lbpix

Had my xe-1 2 weeks now and I'm blown away by the quality of the images taken with the kit zoom lens. The images could easily be printed at about 50" and are in practice comparable to my D800. AMAZING!
In use too I love it. The EVF whilst not as clear as an SLR viewfinder, tells me all I need to know and enables me to see all the menus without putting on reading specs. I use it exclusively in EVF mode. It is light and handles superbly. The image stabilisation seems incredible- so far, as good as the D800 shots from a tripod! If you're in doubt, go and buy one.

2 upvotes
Deardorff

Can the back screen be turned off completely so only the electronic viewfinder is used for composing and shooting?

0 upvotes
vratnik
0 upvotes
newtonseye

when you say ":but powering off usually cleared the error." can you expand a bit on that. Was there a different fix at another time?

0 upvotes
Deardorff

What about shutter lag? Any appreciable delay from the time one pushes the button til the shutter actually releases?

0 upvotes
Total comments: 12