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Canon EOS 20D

By: Shawn Barnett and Dave Etchells

Slightly smaller and lighter upgrade brings greater speed and ease of use along with higher res and lower image noise.

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Page 3:Executive Overview

Review First Posted: 08/19/2004, Update: 11/19/2004

Executive Overview

Too many digital camera purchase decisions are based on pixel count. Most folks look for the highest megapixel count and then pray the camera manufacturer managed to make the camera usable as well. For the record, the EOS 20D has more pixels than most cameras on the market today, at 8.2 megapixels rivaling its bigger, pricier brother, the professional EOS 1D Mark II. But pixel count isn't the most important aspect of the EOS 20D. The 20D impressed us across a wide range of capabilities that reach far beyond mere megapixels. There are too many refinements to point to one that stands out above all the others, but the exciting part is that none of the refinements are there just to make a sale at the retail counter. Every aspect of the 20D is focused on one purpose: to help photographers make excellent images. Our tests indicate that the images are indeed excellent--quite possibly the best we've seen.

As I grip the 20D and turn it around to look from all sides, I see no stickers, no gee-whiz features, no colorful panels or inlays designed to give a "professional" or futuristic look. The 20D is all business. A black body with black buttons and black wheels with silver and blue words and icons. It is a tool, and as such it has only and exactly what's needed to get the job done.

The controls, a refinement of the 10D and Digital Rebel interface, offer very little that is new, just the tried and true EOS design, now more fully streamlined. Even the new Multi-controller is as black as the surrounding body, with no explanatory graphics or words. Its function is obvious and it is effective. Operating in eight directions plus one (pressing straight down to confirm selections) it is tailor-made for selecting any of the outer eight AF points, and pressing straight down re-centers the AF point. You can also use it to pan around in an image in playback mode. It is far superior to using the Quick Control dial on the back, which required the user to press the "change direction" button to the left of the LCD on the EOS 10D to switch between left and right or up and down directions. The new Multi-Controller also comes into play when moving a trimming frame around when doing an in-camera image crop (a new feature) and when setting the sophisticated yet simple white balance correction feature (more on this later).

Aside from the Multi-Controller, externally the 20D is mostly a 10D, just a little smaller and about 3.5 ounces lighter. Almost one quarter inch was shaved off the right side and just a few sixteenths from the height and thickness. The end result is a camera that feels less like a HumVee, built for war, and more like an SUV, built for the road. Put another way, it's less bulky than the 10D and fits more comfortably like the Digital Rebel. Unlike the Rebel, the inside grip area has a sharper contour for a firm hold; a hold reinforced by rubberized grip areas around the front for the four fingers and on the back for the thumb and heel of the hand. Elsewhere the magnesium alloy outer skin has a new finish, one that actually makes it look more like a very strong polymer instead of solid metal. Beneath is a stainless steel frame that gives the 20D that same uncompromised stiffness that made the 10D's body inspire such confidence.

On the back we see three more minor differences from the 10D. The five-button array that lined the left side of the LCD has been reduced by one, largely thanks to the addition of the aforementioned Multi-Controller that obviated the need for the "change direction" button. The Quick Dial On/Off switch has been integrated into the power switch, and the read/write LCD has been moved from the right grip, where it was too often hidden by the right hand, to a slightly better position lower right of the Quick Dial, where it also resides on the EOS Digital Rebel.

Given all that I've said about the EOS 20D's rigid construction, there is one surprising exception: that of the CF card door. It works like the others, but just doesn't feel that strong; certainly not as strong as the door on the 10D. In a camera that shuts off when this door is open, one would think that making sure it doesn't break off would be a priority. Naturally, I haven't tested its limits, but I can't say it'll be as sturdy five years from now.

The guts for speed

Where the 20D gets more exciting than its practical, tuned EOS exterior is when you go inside its magnesium alloy and stainless steel construct. There you'll find a new processor, Canon's own DIGIC II, designed to enable more than half of the 20D's speed improvements. Bits can be read off the card and processed while AF, exposure, and image analysis are simultaneously evaluated for the next shot. The EOS 20D starts up in 0.3 seconds according to Canon (confirmed by our own timing), a major improvement over the EOS 10D's 2.2 second startup time. Shutter lag time has also been improved, taking only 65 milliseconds from when you press the shutter to when an image is captured, according to Canon (our tests show the prefocused shutter lag to be an average of 77 milliseconds, but note that this is a pre-release camera). The DIGIC II processor also enables faster PictBridge printing and USB 2.0 connection to a computer, for significantly faster image transfer--up to 11 times the speed of Canon's USB 1.1 cameras.

All that horsepower begs for more information to process, and the new CMOS imager and advanced shutter are designed to deliver. The 8.2 megapixel imager in the 20D is just a hair smaller than the imager in the Digital Rebel and 10D, measuring 22.5 x 15mm, while the older 6.3 megapixel sensor is 22.7 x 15.1mm. You still use a 1.6x multiplier). The new sensor is made with Canon's latest CMOS design, which includes a high speed 4-channel data readout. Put simply, this means more bits are being moved more quickly from the imager to the processor to make room for the next image. This technology was first seen in the 11 megapixel EOS 1Ds, which has a 2 channel readout. The speedy 8.5 fps, 8.2 megapixel EOS 1D Mark II has the fastest of them all, with 8 channel readout. Canon calls the size of this 8.2 megapixel imager APS-C, because it is the same aspect ratio as the Advanced Photo System Classic frame, only a little smaller overall.

Canon did a complete redesign of the light box, mirror, and shutter on the 20D, bringing everything in tighter for greater efficiency (see photos in Design section). As a result, they were able to speed both frame rate and shutter speeds. The 20D can capture up to five frames per second, at up to 1/8,000 second, with a flash sync speed of 1/250 second. Our tests show the 5 fps to be about right, as we measured about .205 seconds between each shot. The mirror is shorter and smaller than even the Digital Rebel's mirror, and the shutter has been beefed up with stronger magnets and smaller blades. The opening surrounding the imager is cut more closely than in the 10D and Digital Rebel, which means the smaller metal-coated mylar shutter blades have a shorter distance to travel with each shot. Canon says that these and other improvements will make for a more rugged and reliable shutter. While it's not a compelling as the Mark II's remarkably fast shutter sound and mirror retraction, the 20D's mechanism is fast and the mirror gets out of the way in a hurry.

The result of all this technological improvement is that you can hold the shutter down on the EOS 20D and catch between 19 and 32 8.2 megapixel JPEG shots at five frames per second. The extreme variability in this statistic is mostly due to subject variability. More detailed images will compress less and each file will fill the buffer more quickly; our worst case scenario included detailed images with more image noise, taken at 1600 ISO (image noise--while low in the 20D--is still enough to make the image more difficult to compress) and resulted in the 19 frame figure. Our best case scenario included some black objects and was shot at ISO 100 and captured 32 frames. Canon's own figures are 23 frames before the buffer is full. Depending on the card you use, that buffer can empty quickly, in only 12 seconds with the SanDisk Extreme 1GB CF card Canon provided for the review. The Lexar 1GB 80x cards we have here took slightly longer to clear, but were still fast.

Another area where the EOS 20D excels is AF performance. A new AF array is employed, offering nine focus points in a diamond shape. As mentioned earlier, selecting a focus point manually has been made easier with the nine-way Multi-Controller. Surrounding the center are six horizontally-oriented sensors, with two vertically oriented sensors far left and right of the frame. In the center are two cross-type sensors intertwined with one-another, which Canon calls a Hybrid Cross-type sensor. One is the standard F5.6 sensor, designed to work with lenses with maximum apertures of up to F5.6. The second cross-type sensor is bigger, tuned for F2.8 or larger lenses. The camera switches between the two sensors based on the lens's reported maximum aperture when it is mounted on the camera. Because a lens with a larger opening produces a bigger light cone when out of focus, a larger sensor can more quickly make sense of the blur and bring it to focus; it should also offer greater focus refinement, because the sensor covers a larger area. Low light performance is one full stop better, according to Canon.

The final major speed enhancement takes us back outside the camera to the menu interface. Instead of the multi-tabbed menu of the 10D, Digital Rebel, and most Canon PowerShot cameras, the 20D has returned to one big color-coded menu, as we saw on the D30 and D60. The Jump button moves from color to color on the scrollbar, but you can also just keep on turning the Quick Dial and you'll find your item in short order. The tabbed menu is preferable for Five-way navigator-style controls, as seen on the Digital Rebel and PowerShots, but can be painful and problematic when using the Quick Dial, introducing interruptions to an otherwise speedy interface. We're glad to see this one big scrolling menu make a comeback.

Amazingly clean images

Canon employs a number of strategies to eliminate noise, both through processing and through channelling more light to the imager. As we discussed in the 10D review, one disadvantage to the design of a CMOS imager is that each pixel shares its space on the grid with a noise-reduction circuit. Naturally, left to fall freely, some light would miss the active pixel sensor completely, falling on the noise-reduction circuitry instead, leaving critical photons out of the equation. The solution is to use an array of microlenses to direct light away from the inactive portions of the sensor, and onto the active ones. These lenses are literally microscopic. I would love to have been in the room to see the faces of the optical engineers as this solution was put forth to make CMOS technology truly efficient. Nevertheless, the strategy seems to work very well, and Canon's improvement of this technology may be largely responsible for the remarkably smooth images we're seeing. The microlenses on the 20D's imager apparently cover more of the surface area of the chip, thereby channeling more light into each pixel's active area. More light to each pixel means less guessing and error, which amounts to less noise overall.

In addition to the improved microlens structure, Canon has apparently also dramatically beefed-up the on-chip noise-reduction processing. They've so far been very shy about sharing specific details of what processing is actually done on the sensor, but have indicated that there are now three separate noise-reduction processing steps that are performed on-chip, before the data ever gets to the camera's processor. Whatever the case, the 20D's images are remarkably clean, even at ISO 1600.

The 20D has not only benefited from Canon's professional SLR technology and experience with professional photographers using cameras like the 1Ds and 10D, but a few lessons from the extremely successful Digital Rebel show themselves as well. Not only is the camera lighter and smaller like the Rebel, it accepts EF-S lenses, Canon's "short back-focus" lens design. Indeed, just like the Digital Rebel, the 20D will be available with or without the original 18-55mm lens bundled with the camera. Prices are expected to be US$1,499 body only, US$1,599 with the non-USM 18-55mm lens, and US$1,999 with the new EF-S 17-85mm IS USM lens, an image-stabilized 27-136mm equivalent wide/tele zoom.

Canon has also announced three new EF-S lenses, tuned specifically to their APS-C-sized digital cameras. First is a USM (ultrasonic motor) version of the 18-55mm original. This first appeared on the Japanese version of the Digital Rebel, but was unavailable to US or International customers. Now it's available for US$169. More exciting are the 10-22mm USM wide angle lens (US$799) and 17-85mm USM IS lens (US$599), finally making ultra wide angle and short image-stabilized zoom available to these more affordable SLRs. The 17-85mm lens is designed to provide similar coverage to what the extremely popular Canon EF 28-135mm IS USM lens offers on a 35mm camera. This new lens should be very popular for consumers and event photographers, because this lens offers great handheld performance, with the image stabilization enabling shutter speeds of around two to three stops slower for better indoor and low light photography.

Another Digital Rebel feature that made it in as an option is Parameter 1, something set by default on the Digital Rebel, but only made available as an option on the 20D. By default, the 20D is set to Parameter 2, which mostly matches the 10D for contrast, sharpness, and saturation. Users wanting to tweak their images later, either with Canon's latest PC-based RAW format interpreter, or in Adobe Photoshop, will likely want to stay with Parameter 2. Users wanting more saturated and sharper images out of their camera, and those printing directly to a PictBridge printer--which is most consumers--will want to switch to Parameter 1 for sharper, more contrasty, and vibrant images with minimal computer-side touch up. Users can also save their own parameters by modifying the three user-definable "sets."

One of the only disadvantages to the EOS 20D is the lack of an AF assist lamp. AF assist is only possible when the built-in flash is deployed. The camera uses a rapid set of flash pulses to momentarily illuminate the scene. While we're talking about the onboard flash, it's noteable that it pops up a little higher than the 10D, more like the Digital Rebel, but it pops up more quietly than the Digital Rebel. Both the pop-up and hotshoe-mounted flashes use Canon's new E-TTL II for better flash performance, using lens focus data to determine distances of objects in the frame.

The EOS 20D is an impressive offering. We'd call it a carefully planned amalgam of speedy components, refined imaging, tuned design, and the best Canon can offer for the price of a mid-range digital SLR (it's actually the entry-level Pro SLR). While the ever-escalating war of digital SLRs will doubtless continue, for the moment at least, the 20D really stands alone in the market, not only in its price class, but even when compared with cameras costing considerably more.


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