Why You Can Trust CNET Canon EOS 40D review: Canon EOS 40D
Canon EOS 40D
Editors' note: The competitive landscape for this camera has changed since our review, and we've updated the text and ratings to reflect that and the model's lower price. The design rating goes from a 9 to an 8--while still a nicely designed model, it's not particularly outstanding anymore--and features drops from an 8 to a 7 for its efficient-but-now-relatively-mundane set of capabilities. Text changes include comparisons to newer models.
The Good
The Bad
The Bottom Line
Representing a more significant leap over the EOS 30D than the 30D was beyond the 20D, the Canon EOS 40D features a redesigned body and menu system, introduces some long-requested features, integrates some of the new technology from the EOS 1D Mark III and delivers a nice bump in resolution and performance. All of that, plus a solid overall increase in speed over its predecessor, make it a no-brainer upgrade from previous models, a substantially better option than its down-the-line sibling, the EOS Rebel XSi and a nice complement for the EOS-1D Mark III.
Canon offers two configurations of the 40D: body only, and a kit with the veteran f/3.5-to-f/5.6, 28mm-to-135mm IS USM lens. Taking into account the camera's 1.6x focal-length multiplier yields an angle of view equivalent to that of a 44.8mm-to-216mm lens on a 35mm camera. That's a bit narrow, though; personally, I think the admittedly pricey EF 24mm-to-70mm f/2.8L USM covers a more useful general-purpose range of 38.4mm to 112mm. Alternatively, you may want to wait until later this year when the inexpensive EF-S 18mm-to-55mm f/3.5-to-f/5.6 IS is slated to become available.
Despite the growth of the LCD from 2.5 to 3 inches, the body size and weight of the 40D is the same as that of the 30D: 4.2x5.7x2.9 inches and roughly 1.8 pounds. As with its predecessor, the body feels very solid and well made, one of the important advantages it has over the flimsier-feeling Rebel series. Canon added dust- and weatherproofing on the CF slot, the buttons, and all connection points, and it implemented the same integrated sensor-cleaning system that's in the Mark III series. The latter vibrates the sensor to dislodge dust during start-up and shut-down (pressing the shutter cancels cleaning during start-up), and if that doesn't work, a Dust Delete Data option enables the camera to analyze and remember where it senses dust and algorithmically remove it from photos.
The larger LCD did make it necessary to rejigger some of the controls. The Review, Delete, Jump, Info, and new Picture Styles buttons now sit below the LCD rather than to the side, and the buttons are substantially smaller than before. They also sit flatter and more flush with the body, making them harder to feel and press. Along the same lines, the Metering/WB, AF/Drive, ISO/Flash compensation, and LCD backlight buttons, which seem to rise slightly higher than previously, feel identical and impossible to differentiate from one another.
On the upside, the 40D has a bigger, more tactile mode dial, with three slots for User settings (the 30D had none). Although I find these invaluable, there's one behavior that really annoys me: if the camera goes to sleep, it resets any setting overrides you've made while in one of the user modes.
Canon also redesigned the grip, adding a curved indentation just below the ledge with the shutter button, where your middle finger falls. It's a subtle but nice ergonomic enhancement that makes the grip feel just a little more solid. Canon also redesigned the menu system, which is now far easier to read and navigate. (Click through a slide show discussion of the body design and menus.)
A few new features have also popped up with the 40D. Most notably, it offers a Live View mode, with a better, more flexible implementation than that of the 1D Mark III--or most others, for that matter. Unlike its big brother, you can autofocus in Live View; when you press the AF-ON button, it flips the mirror down, focuses, then flips the mirror back up so the focus-corrected view appears on the screen. On the downside, it focuses only using the center AF area. And regardless of focus mechanism, it uses only evaluative metering.
As with a point-and-shoot camera, you can pull up a magnified view to help with manual focusing. In addition, three so-called "silent shooting" options allow you to control the shutter curtain reset to delay the noise and minimize vibration. Though hardly "silent," the 40D does have one of the quieter Live View modes I've encountered. You can also set the metering timer, how long the camera holds and displays the metering information after you release the shutter button, anywhere from 4 seconds to 30 minutes. I'd love this feature to be available for general shooting rather than limit it to Live View. All that said, Live View shooting continues to be a bit of a niche application for dSLRs; generally, it's suitable only if your subject matter allows for a tripod and optimally a connected PC for remote control. Keep in mind that the sensor can get warm in this mode, and as Canon warns, increased heat will result in increased image noise.
For more meat-and-potatoes changes, the 40D now supports Auto ISO in all modes beyond full Auto, which comes in handy every now and then. The new viewfinder system supports interchangeable focusing screens and, for all you four-eyed photogs, offers a relatively high 22mm eyepoint and slightly greater magnification than that of the 30D, 0.95 vs. 0.90. Canon also added an sRaw format, which shoots small, 2.5-megapixel raw images. I don't see the utility of this feature, but it's easy enough to ignore. Not so easy to ignore is the increased spot size for the spot meter, up to 3.8 percent of the viewfinder from the 30D's 3.5 percent. (Here's why that's bad.)
Other features--and the 40D has plenty--remain pretty much unchanged. These include three 9-point autofocus modes: Single-shot, AI Servo tracking autofocus, and AI Focus, which switches between Single and AI Servo if it detects that the subject has moved. Unfortunately, the AI Focus can't tell the difference between subject movement and the photographer doing a focus-and-recompose, so you're usually better off picking Single or Servo and sticking with it. Four metering modes--evaluative, partial metering (approximately 9 percent of the viewfinder), the aforementioned 3.8 percent spot, and center-weighted average metering--provide reasonable flexibility. It's got a full slate of white-balance settings, including bracketing and custom corrections along the blue, amber, magenta and green axes; color temperature; and manual. A few scene program modes--portrait, landscape, macro, sports, and night portrait--augment the semimanual program, aperture- and shutter-priority, automatic depth-of-field AE, and manual exposure modes. Relevant maximums include a top shutter speed of 1/8,000 second and top flash sync speed of 1/250 second.
Though the 40D isn't missing any feature in particular--though I could make a case for mechanical image stabilization--one feature I'd really like to see trickle down from the 1D series, and which I think makes a lot of sense in a camera of this class, is the ability to define acceptable ranges for aperture, shutter speed, and ISO sensitivity when shooting in one of the exposure-priority modes.
As for performance, the 40D is reasonably speedy for its class, and roughly 20 percent faster overall than the 30D. But it still can't keep up with the faster D80. From a cold start to first shot takes only 0.3 second, and under optimal conditions it can focus and shoot in only 0.4 second. A healthy buffer and fast card writes allows the 40D to maintain that pace from shot to shot for both JPEG and raw. Flash recycle time adds slightly less than 0.2 second to that. The 40D has slow- and high-speed burst modes which test out at 3.1 frames per second (fps) and 6.3fps, respectively; the slower mode is for preventing buffer lockups when using a slow CF card. I also found the slower mode a useful speed option when shooting with the Speedlite 580EX flash with sluggishly recycling alkaline batteries. Note that in the case of the 40D a "slow" CF card does not mean "anything slower than UDMA." It doesn't support UDMA, and seems to have sufficient buffer to maintain maximum throughput even with a last-generation SanDisk Extreme III (133x) card.
However, the camera does hit one sour performance note: leisurely low-contrast focusing, which ratchets up low-light lag to 1.2 seconds. This is despite Canon's claim of a 30 percent increase in AF calculation speed. Though not uncommon for a dSLR, we really expect better, especially for this price class. Canon rates the battery, the same 1,390mAH BP-511A used by the 30D, at 1,100 shots (sans flash). Though this is reasonably long, Canon lags behind many of the other manufacturers for providing intelligent power display and estimates of power remaining. The large, bright LCD is easy to view, but like even the best camera LCDs, it renders relatively poor representations of color and exposure.
Photos show excellent dynamic range, with no visible clipping in the highlights or shadows (of correct exposures). Though they definitely fall within an acceptable range, automatic white balance under artificial lights tends to be a bit warm, and even manual white-balance shots measure a tad green-heavy. Automatically balanced sunlit shots render a bit cool. With the exception of certain types of spot-metering cases that I discuss in the slide show, all of the metering schemes delivered excellent, balanced exposures. The 40D's ISO sensitivity caps out at ISO 3,200 and remains visually unobtrusive as high as ISO 800. Beyond that, you can spot noise, but it doesn't jump out of the shadows and knock you over the head.
For Canon devotees, the EOS 40D is a great camera and remains an excellent choice compared with most of the dSLRs in and around its price class--with one exception. Despite its many attractions, the Canon EOS 40D doesn't clearly outshine its closest competitor, the Nikon D90. Though the 40D has the obvious advantage for action shooting--almost double the burst rate and a higher top shutter speed--the D90 generally feels a bit faster and more responsive for single-shot photography, and offers video capture (though flawed) and a higher resolution. I think the 40D ultimately does deliver better photo quality, but some people might find the differences more subtle. And, of course, the more expensive Canon EOS 50D remains a wild card until we've tested it. So for the moment, the 40D gets a hearty, if not wholly unqualified, endorsement.
(Shorter bars indicate better performance)
 | Time to first shot | | Raw shot-to-shot time | | Shutter lag (dim light) | | Shutter lag (typical) |
(Longer bars indicate better performance)