SIX, EIGHT, TEN, TWELVE --
the Rebel line continues up the megapixel count to the fourth-generation EOS Rebel XSi. But the 12.2MP XSi ($800, street, body only; $900 with 18-55mm f/3.5-5.6 Canon EF-S IS lens) is a lot more than just another deuce worth of dots. Enough upgrades to performance and convenience have been added -- some trickle-downs from the pro-level EOS-1D series -- that the XSi qualifies far more as an enthusiast model than an entry-level one. Here are five reasons why.
1. GREAT IMAGE QUALITY
The XSi uses a new Canon CMOS sensor with extra-large microlenses, plus 14-bit A/D conversion rather than 12-bit. Performance in the Pop Photo Lab was impressive: It scored Excellent image quality throughout its ISO 100-1600 range, based on Excellent resolution (2265 lines average), Excellent color accuracy, and noise levels that ranged from Very Low at ISO 100 to Moderately Low at ISO 1600.
What really wowed us, though, was the consistency of its test results. At ISO 800 and 1600, resolution declined by less than 5 percent, resulting in a still-Excellent 2160 lines average resolution. RAW files converted to TIFF at default settings with Canon's included Digital Photo Professional software showed just about the same resolution as JPEGs. The application of high-ISO noise reduction at ISO 800 and 1600 resulted in, amazingly, no discernable decrease in resolution, so we'd suggest leaving it on all the time.
Overall, this is the best imaging performance we've seen so far in the "step-up" class of DSLRs in the $800-900 price range (see Competitive Set for details), and betters that of several more-expensive cameras.
For example, the 14.6MP Pentax K20D ($1,130 street, body only), tested in the March 2008 issue, had slightly higher resolution at ISO 100 but dropped off more quickly at higher ISOs, and it had serious color-accuracy and noise problems in JPEGs over ISO 400. For that matter, Canon's own EOS 40D ($1,140 street, body only), while providing Excellent image quality, is a tick behind the XSi across all indicators. Of cameras costing under $2,000, only the Nikon D300 provides better imaging overall.
Of course, the pricier DSLRs have ISO sensitivities above 1600, and the XSi does not. But given the camera's price, we really can't argue with Canon taking the safe route here.
2. FASTEST IN CLASS
The first Rebel to get Canon's DIGIC III processor, the XSi is currently the quickest-firing 12MP camera in this class, rated at 3.5 frames per second, and for highest-quality JPEGs, up to 53 frames. (The new Olympus E-420 and E-520, both 10MP models, are rated at 3.5 fps up to the capacity of the card, and we will test that claim very soon.) Using a 2GB Panasonic Class 6 SD card, we got 53 and occasionally 54 frames at about 3.6 fps. But the XSi would keep on firing at just under 2.5 fps until the card filled up.
The camera is rated for bursts of up to 6 RAW or 4 RAW + JPEG, which we found accurate. It can continue firing single RAW frames every second or so after that. Also speeding up the shooting is the 9-point autofocusing, essentially the same as the XTi's, which was already the fastest in class and one of the fastest in any DSLR. The XSi does get a high-precision central cross sensor for f/2.8 and brighter lenses. (Fast lenses, with their shallower depth of field wide open, benefit from a high-precision sensor.) Our AF test of the XSi showed it to be about the same speed as the XTi in bright to medium light, and somewhat faster at the lowest light levels.
To keep all this speed powered up, the new lithium ion battery in the XSi, while the same size as the XTi's, provides 50 percent more shots per charge, according to the CIPA rating.