Canon 50D Performance

Excellent speeds for a prosumer digital SLR.

Fast startup and shut-down times, fast enough that they're difficult to measure. Enabling sensor cleaning on shut-down adds about 2.5 second delay. Buffer clearing times are quite good, but depend on the image quality, size and speed of the memory card.

Canon claims that the 50D can run faster than any currently-available memory cards, so it's clearly a camera that you'll want to use fast cards in. To demonstrate this, they included a SanDisk "Ducati" 4GB CF card with the camera. SanDisk rates these cards at 45MB/second read/write speeds. Kingston rates their 266x cards at 45 MB/sec read and 40 MB/sec write, and our own testing of the two cards in high-speed card readers copying data to/from a 320 MB/second SCSI RAID array found the two cards fairly close in performance. (Both cards measured ~42 MB/sec when reading, the Kingston wrote at ~33MB/sec write, while the Ducati could write at ~42 MB/sec). In the Canon 50D, though, we found the Ducati card was dramatically faster, turning in buffer clearing times as much as 3.4x faster than those for the 266x Kingston. We're not sure just what's so different with the Ducati card, but if you want the absolute maximum throughput on your Canon 50D, we'd recommend getting one of these cards. They're rather pricey and only a few dealers are carrying them at this point, but they could be well worth the price if you're a sports shooter. Here's a PriceGrabber link to shop for SanDisk Ducati cards.

Mode switching times are good, though Record to play is a bit sluggish.

Full autofocus shutter response is very good at 0.131 second using our standard single-point AF test. Letting the camera choose the focus point increased lag slightly to 0.179 second on average. Enabling the built-in flash increased full AF lag just slightly to 0.241 second: that small an increase is excellent. "Prefocusing" the camera by half-pressing and holding down the shutter button before the final exposure results in a lag time of only 0.063 second. Manual focus was slower, at 0.120 second.

Lag time in Live View mode can vary all over the map. Full AF in Live View mode is not supported directly, since pressing the shutter button does not initiate autofocus; the AF-On button must be used. Once focused, the shutter lag is 0.279 second which is more than four times slower than prefocused in normal shooting mode, but still not bad for Live View. Half-pressing the shutter button prior to snapping the shot dropped this to 0.108 second. If we measured the lag time from pressing the AF-On button to the final shot, the best we could manage was about 0.85 second, typical of most SLRs' phase-detect AF modes in Live View shooting.

Contrast-detect AF was a lot slower, as is usually the case, and was also subject to enormous variation in the time it took to focus. We normally use a Sigma 70mm f/2.8 macro lens for measuring lag time, because phase-detect systems seem to be able to determine focus quite quickly with it. With Contrast-Detect focusing, though, the camera has to move the lens elements back and forth before it can tell whether the subject is in focus or not, so the operating speed of the lens becomes a factor. The average lag with the Sigma was 4.42 seconds, with a lot of variation between fastest to slowest (+/- 34%). With the Canon lenses, the average was lower, ranging from 2.06 seconds for the EF-S 17-85mm f/4-5.6 IS USM to 3.40 seconds for the EF 28-135mm f/3.5-5.6 IS USM, with only +/- 3% to +/- 6% variation, depending on the lens.

Shot-to-shot cycle times in single-shot mode were quite fast, at about 0.25 second for any quality. Buffer length was more than 20 shots for JPEGs, but dropped to 15 for RAW and 12 for RAW+JPEG.

Continuous mode speeds are very good, our measured speeds matched the camera's rated 6.3 frames/second. Measured buffer depths were more than 20 frames for large/fine or small/normal JPEGs (we got 43 L/F JPEGs with the SanDisk "Ducati" card), 14/15 frames for RAW mode and 10/11 frames for RAW+JPEG. (Note that in our cycle time testing we shoot a target consisting of a fine-grained digital noise pattern, designed to be very hard to compress. This gives us worst-case buffer capacity numbers: You're likely to see greater buffer capacity when shooting more normal subjects.)

The flash took only 1.9 seconds to recharge after a full-power pulse, which is very fast.

Connected to a computer or printer with USB 2.0, download speeds are very fast. (First number with Kingston 266x 2GB, second with SanDisk "Ducati" 4GB CF card.)

Bottom line, the Canon 50D is very fast in just about every aspect of its operation. Continuous modes are fast enough for most moving subjects, and shutter lag and cycle times are fast as well. Excellent performance overall for a prosumer model.

Battery
Very good battery life for a lithium-ion SLR design, but Live View burns a lot more power than normal shooting with the optical VF.

The Canon 50D uses a custom rechargeable lithium-ion battery for power, and ships with a charger. Although battery life is good, we recommend you pick up a spare battery and keep it freshly charged and on-hand for extended outings, and especially if you plan on using Live View mode a lot.

The table above shows the number of shots the camera is capable of (on a fully-charged rechargeable battery), based on CIPA battery-life and/or manufacturer standard test conditions.

(Interested readers can find an English translation of the CIPA DC-002 standards document here. (180K PDF document))

Storage
The Canon 50D accepts CompactFlash memory cards, and does not ship with a card.

We strongly recommend buying a large capacity CompactFlash memory card at least a 1GB card, preferably a 4 or 8GB one, to give yourself extra space for extended outings, or when shooting RAW files. (Check the shopping link above, cards are really cheap these days, so no reason to skimp.)