Editor's note: This blog has been updated to reflect new information from Canon regarding the number of JPEGs the Rebel XSi can shoot in a single burst.
Canon fans looking for an update to the 5D will have to wait a little longer it seems, since the company just announced an update to the entry-level XTi as its big PMA SLR news. You shouldn't be disappointed, though, since the new Rebel XSi makes a good showing in the entry-level dSLR category. The XSi has a 12.2-megapixel APS-C size (1.6x field of view conversion factor) CMOS sensor, 14-bit A/D conversion to allow for more possible color gradations when shooting RAW, a Live View shooting mode with contrast detection autofocus so the camera doesn't have to lower the mirror to focus in that mode, and (some might say finally) a 4 percent spot meter.
A 3-inch, 230,000-pixel LCD provides a nifty screen with which to frame shots in Live View mode, though it's not quite as versatile as the articulated screens found in Panasonic's DMC-L10 or Olympus' higher-end E3. As in its predecessor, sensitivity ranges from ISO 100 to ISO 1,600. I was hoping Canon would at least push that up to ISO 3,200 this time out, but since their competitors haven't pushed their entry-level SLRs that far yet, we can't hold that against Canon too much. It does say that the Digic III processor in the Rebel XSi, along with the high-ISO noise reduction inherited from the high-end EOS 1D Mark III and large microlenses over each pixel, should make for lower noise at higher ISOs when compared with previous Rebels. We'll have to wait and see once we get a review sample, though we were quite impressed with the noise profile of the 1D Mark III.
While the Rebel XSi sticks with a nine-point autofocus system with the same placement as the XTi, Canon says it's using a new AF sensor in the XSi that the company claims will improve subject detection compared with previous models. The center AF point uses a cross-type sensor that provides enhanced performance with lenses that have a maximum aperture of f/2.8 or faster. That doesn't help much with the EF-S 18-55mm f/3.5-5.6 IS (image stabilized) lens that comes with the kit, but if you decide to buy one of Canon's fancier lenses in the future, it may come in handy. However, lenses with a maximum aperture of f/2.8 tend to be expensive and aren't what I'd expect a Rebel XSi owner to buy, with the possible exception of specialty lenses, such as a macro. On a positive note, it is nice to see Canon include an IS lens in its entry-level kit, since some of its competitors now include sensor-shift IS in their entry-level dSLRS. It was also pleasing to see that Canon increased the viewfinder magnification to 0.87x from the XTi's 0.8x.
Soccer moms should like the fact that the Rebel XSi is the fastest Rebel to date, able to pop off 3.5 frames per second for up to 53 large/fine JPEGs or up to 6 RAW images. Strangely, that's a step up from the XTi's maximum of 27 large/fine JPEGs, but a step down from the XTi's 10 RAW frames per burst. According to Canon, this increase in JPGs comes from the Digic III processor's ability to process JPGs significantly faster than the processor found in the Rebel XTi, while the decrease in RAW images is due to the increased resolution of the XSi's sensor.
The camera also includes the same Highlight Tone Priority mode found in the 1D Mark III, which helps preserve detail in the brightest portion of a scene. Also, the XSi includes Canon's Auto Lighting Optimizer, which automatically adjusts contrast and brightness in case the image you captured isn't quite perfect. Introduced last year in the 40D, the Auto Lighting Optimizer is now available in all exposure modes and employs face detection to prevent underexposure of backlit faces. That's nice, since underexposed backlit subjects was one of Lori Grunin's gripes about the Rebel XTi.
Unfortunately, Canon didn't address one of my big gripes with the XTi-- its lack of a dedicated status LCD. Instead, the XSi sticks with the lone 3-inch screen, which doubles as a status display and automatically shuts off when you raise the camera to your eye, thanks to a sensor just below the optical viewfinder. If you're not careful when you switch lenses, you'll like that Canon kept the Integrated Cleaning System in the XSi. It shakes the sensor so that any loose dust falls away from the low-pass filter in front of the sensor and is held on an adhesive strip in the bottom of the camera.
In case that's not enough, you can have the camera map any persistent specks so the Digital Photo Pro software that comes with the camera can remove the resulting spots in your image. In case you want to risk cleaning your sensor yourself, the camera can also hold the mirror up so you can reach into the body and risk scratching the low-pass filter while you try to remove any particles.
Joining the growing number of dSLRs that record to SD instead of Compact Flash cards, the XSi will record its images to SD or higher-capacity SDHC cards. For users stepping up from a compact camera this may be convenient, though previous Rebel owners looking to step up will likely have to run out and buy some SD cards. Remaining specs are in line with the previous Rebel. For example, shutter speeds range from 30 seconds to 1/4000 second with a flash sync speed of 1/200 second and the camera employs a 35-zone TTL metering system. Canon plans to offer the Rebel XSi both as a body only ($800) and as a kit with the EF-S 18-55mm f/3.5-5/6 IS lens ($900). Both should be in stores by this April and it should be noted that the Rebel XSi will be available in silver and black finishes and Canon will also offer the BG-E5 battery grip for the new camera.