Editor's note March 28, 2008: The rating for the D40x has been lowered since the review was originally published to reflect changes in the capabilities of current comparable models from other manufacturers.
When the Nikon D40 came out late last year, one of the chief complaints people had was that it only had a 6-megapixel imaging sensor. Not being the type to ignore its customers, Nikon has introduced the D40x, which is nearly identical to the D40, but includes a 10.2-megapixel CCD sensor. Of course that means you now have to choose between saving some money--and possibly buying another lens or accessory--and getting more megapixels. Plus, if you're a more experienced photographer, you'll also have to weigh the D40x against the 10.2-megapixel D80, which offers controls and features that are geared toward people who have used an SLR before.
Like its non-x sibling, the D40x includes the same processing engine as the Nikon D200 and the same 420-pixel-sensor 3D Color Matrix Metering II system found in the D80. While the D40 can only be purchased in a kit with the 18mm-to-55mm f/3.5-to-f/5.6 lens, the D40x is available in four options: body only; with the same 18mm to 55mm as the D40; as a two-lens kit with that 18mm to 55mm and a 55mm-to-200mm f/4-to-f/5.6 VR (Nikon's smallest, lightest, and least-expensive vibration-reduction lens to date); or with the same nice 18mm-to-135mm f/3.5-to-f/5.6 available with the D80. Astute Nikonians will note that all these lenses bear the AF-S designation. That's because, like the D40, the D40x doesn't include an autofocus coupling pin, so if you want to use autofocus, you're limited to AF-S or AF-I lenses. In our field tests, among other lenses, we also used a 50mm f/1.4 Nikkor AI-S and a 60mm f/2.8D AF Micro-Nikkor. Both communicated flawlessly with the body, which successfully controlled the lens' aperture blades. The only drawback was we had to focus on our own, which was a relatively pleasurable experience, especially for an entry-level SLR, thanks to the D40x's fairly bright 0.8x viewfinder. However, if you have trouble keeping your horizon straight, you should note the finder lacks any sort of grid.
The camera body itself is on the small side, keeping in line with most of the entry-level dSLRs on the market. It has a well-formed grip, with a slight indentation on the inside that adds to its solid feel, though like the smaller Pentax models and the Canon Rebel XTi, your pinky finger will likely dangle below the camera. In a sacrifice to size (and possibly cost), you won't find a second status display, as you do on the tops of most mid- and pro-level dSLRs. Instead, the 2.5-inch LCD does double duty, serving up camera settings, in addition to its normal role of menu access and image playback. Nikon's new graphic-based interface, introduced in the D40, lives on in the D40x. While it looks nice, and does a good job of showing users the effects of the camera's various controls, the new control scheme isn't particularly intuitive, so users who don't read their manuals may hit a few snags. For example, while we did find it intuitive to press either the Info button near the shutter or the "i" button on the camera back to bring up the shooting information screen, we had to consult the manual to discover that a second press of the "i" button lets you navigate through that screen to change settings such as white balance, ISO, metering, AF mode, or image size and quality. We laud the simplicity of this approach, but the double-button-press process slowed us down during our field tests.
While Nikon's not alone in putting a 3-point autofocus system in its entry-level dSLRs (Olympus' E410 and E510 also use 3-point systems), some competitors, such as Canon's Rebel XTi (9-point AF) and Pentax's K100D and K110D (11-point AF) include more sophisticated autofocus systems. In our field tests, the D40x had occasional difficulty locking on subjects, sometimes choosing the wrong object, but more often was just a bit sluggish. In other areas, the D40x surpasses some of the competition. Its sensitivity settings range from ISO 100 to ISO 1600, plus an H1 setting, which is essentially equivalent to ISO 3200. By contrast, the D40's lowest sensitivity is ISO 200, as are the Pentaxes'. Canon's XTi and the two Olympuses start at ISO 100, but top out at ISO 1600. Shutter speeds on the D40x range from 30 seconds to 1/4000 second, and exposure compensation covers a rather wide swath of plus or minus 5EV in third-stop increments. However, the scale used to show exposure compensation in the viewfinder and on the LCD screen only covers plus or minus 2EV, so beyond that, you need to pay attention to the tiny numerical indicator next to the scale. All other exposure controls also run in third-stop increments, as opposed to the more-coarse half-stop increments that some cameras, such as the Fujifilm S3 Pro, use.