Canon EOS 350D Digital RebelCanon makes an impressive update to their wildly popular "Digital Rebel."!<<Exposure and Flash :(Previous) | (Next): User Interface>> Page 9:TimingReview First Posted: 3/23/2003, updated: 6/4/2005 |
Timing
When you press the shutter release on a camera, there's usually a lag time or delay before the shutter actually fires. This corresponds to the time required for the autofocus and autoexposure mechanisms time to do their work, and can amount to a fairly long delay in some situations. Since this number is rarely reported on (and even more rarely reported accurately), and can significantly affect the picture taking experience, I routinely measure both shutter delay and shot to shot cycle times for all cameras I test, using a test system I designed and built for the purpose. (Crystal-controlled, with a resolution of 0.001 second.) Here are the numbers I collected for the Canon EOS Digital Rebel XT:
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(secs) |
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| Power On -> First shot | |
Very quick; difficult to measure. (A huge improvement over the original Rebel.) |
| Shutdown | |
First time is simple shutdown, second time is worst-case buffer-clearing time. Buffer clearing is a little on the slow side, but that time does correspond to emptying either four large/fine 8-megapixel JPEGs or 3 RAW+JPEG images from the buffer. Buffer clearing is significantly faster than on original Rebel. |
| Play to Record, first shot | |
Almost immediate; always ready for a shot. Also a dramatic improvement over the original Rebel. |
| Record to play | |
First time is that required to display a large/fine file immediately after capture, second time is that needed to display a large/fine file that has already been processed and stored on the memory card. Quite fast, a good 3x faster than original Rebel. |
| Shutter lag, full autofocus | |
First time is at full wide-angle, second is full telephoto. Very good shutter response. (Only slightly faster than the original model.) |
| Shutter lag, continuous autofocus |
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As usual, no reduction in shutter lag for static subjects, but also (happily) no penalty either. |
| Shutter lag, manual focus | 0.168 |
Reasonably fast, if not startlingly so. Still an improvement over the 0.248 seconds of the original model. |
| Shutter lag, prefocus | 0.095 |
Time to capture, after half-pressing shutter button. Very fast. (Original Rebel was 0.142 sec.) |
| Cycle Time, RAW / RAW + large JPEG | 0.38 |
Times are averages. In RAW mode, shoots 5 frames this fast, slows to about 1.4 seconds per shot, and clears the buffer in 7 seconds. In RAW+JPEG mode, shoots 4 frames this fast, slows to about 2.3 seconds per shot, and clears the buffer in 9 seconds. Pretty fast, decent buffer depth. (Clearing times measured with Lexar 80x CF card.) |
| Cycle Time, max/min resolution | 0.36 (2.8 fps) |
Times are averages. Cycle time is 0.36 seconds regardless of resolution. In large/fine mode, shoots 13 frames this fast, then slows to .75 seconds per shot. At lowest resolution, maintains this pace indefinitely. Buffer clears in 6 seconds for large/fine images, almost immediately for lowest resolution. Pretty fast, dramatic improvement in buffer depth relative to the 4 frame capacity of the original Rebel. (Clearing times measured with Lexar 80x CF card.) |
| Cycle Time, RAW / RAW + large JPEG, continuous mode | 0.35 |
Times are averages. In RAW mode, shoots 5 frames this fast, slows to about 1.4 seconds per shot, and clears the buffer in 6 seconds. In RAW+JPEG mode, shoots 3 frames this fast, slows to about 2.4 seconds per shot, and clears the buffer in 9 seconds. Once again, good speeds, reasonable buffer depth. (Clearing times measured with Lexar 80x CF card.) |
| Cycle Time, max/min resolution, continuous mode | 0.35 (2.89 fps) |
Times are averages. Cycle time is 0.35 seconds regardless of resolution. In large/fine mode, shoots 13 frames this fast, then slows to .71 seconds per shot. At lowest resolution, maintains this pace indefinitely. Buffer clears in 6 seconds for large/fine images, 1 second for lowest resolution. Good speed, good buffer depth. (Clearing times measured with Lexar 80x CF card.) |
Shooting speed is one area where improvements in the new Canon Digital Rebel XT relative to the original Rebel are most apparent. Autofocus speed is roughly the same, but essentially every other measure of performance shows significant improvement over the prior model. The feature existing Rebel users will most appreciate/envy is the XT's much greater buffer depth, shooting as many as 13 large/fine images before having to wait for the memory card to catch up. Once the buffer is full, the XT also writes to the memory card much faster as well, emptying a full buffer in just nine seconds, compared to about 17 seconds in the earlier model. While the resolution increase in the XT may not be enough to get current Rebel owners to upgrade, the increase in shooting speed very well might.
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