"Picky Details" for the Sony DSC-S90 digital camera
(Timing, Power, and Storage Info)
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 Sony DSC-S90:
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(secs) |
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| Power On -> First shot |
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LCD turns on and lens extends forward. A bit faster than average.
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| Shutdown |
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First time is time to retract lens, second time is worst-case buffer-clearing time. On the slow side.
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| Play to Record, first shot |
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Time until first shot is captured. Very fast.
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| Record to play |
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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. Pretty fast.
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| Shutter lag, full autofocus |
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First time is at full wide-angle, second is full telephoto. Much faster than average. |
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Shutter lag, continuous autofocus |
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As usual, no benefit to continuous AF for stationary subjects. (May help with moving subjects, but I have no way to test that.)
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| Shutter lag, manual focus |
0.204
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Quite fast. |
| Shutter lag, prefocus |
0.010
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Time to capture, after half-pressing shutter button. Amazingly fast! |
| Cycle Time, max/min resolution |
1.07 / 1.02 |
First number is for large/fine files, second number is time for "TV" mode (640x480) images. Times are averages. In both modes, clears the buffer after each shot and continues at this pace indefinitely. Very good, much better than average, particularly among cameras of this price class. |
| Cycle Time, continuous mode, max/min resolution | 0.63 / 0.56 (1.58 / 1.78 fps) |
First number is for large/fine files, second number is time for small/basic images. Times are averages. Shoots 4 images this fast in large/fine mode, or 30 images with smallest file size, before stopping to clear the buffer. Buffer clears in 2.5 seconds for large/fine shots, in 5 seconds for "TV" sized images. Quite good. (Note that buffer-clearing times are for Memory Stick PRO media, ordinary Memory Sticks will be slower.) |
| Cycle Time, "Multi Burst" mode | 0.03 (30 fps) |
Camera captures sixteen 640 x 480 pixel images, stores them in 4x4 arrays inside normal 1280x960 files. Frame rate can be set to 30, 15, or 7.5 fps. Buffer clears in about a second, and it's ready for 16 more. Very fast. |
Surprising speed. The Sony DSC-S90 is only slightly faster than average starting up, and slower than average shutting down, but when it was running, it was a surprisingly zippy little camera. Full-autofocus shutter lag was dramatically faster than average, at only 0.31 - 0.41 second. When the camera was "prefocused" by half-pressing and holding down the shutter button before the shot itself, shutter lag dropped to an astonishing 0.01 second. Shot to shot cycle time was also very fast, at only 1.07 second for large/fine JPEG images. In continuous mode, the camera could capture up to 4 large/fine images at a time, one every 0.63 second. (1.58 frames/second.) Bottom line, the Sony DSC-S90 should be a great camera for keeping up with an active family or capturing shots of sporting events.
Power
The Sony DSC-S90 uses a two AA batteries for power, and two Sony-branded 2100 mAh NiMH batteries are included with the camera. Unfortunately, the camera uses a "dummy battery" AC adapter (rather than a standard external power connector), so I couldn't conduct my usual direct measurements of power consumption. For what it's worth though, Sony claims that the S90 will run for as much as 210 minutes in capture mode with the LCD display turned on, capturing up to 420 full-resolution images. If true (and I have no reason to disbelieve it), the DSC-S90's battery life is very good, particularly for a camera powered by only two AA cells. IMPORTANT NOTE: While it showed excellent battery life with the included Sony NiMH batteries, we found that the DSC-S90 was very finicky about the quality of the cells used with it. A number of well-rated NiMH cells we had here in the studio just wouldn't power it at all, or produced very short run times. Sony's cells appear to be manufactured by Sanyo, so I imagine that other Sanyo-sourced NiMH cells (here in the US, that would be Kodak and Energizer brands) would also work well. The safest bet though, would be to use Sony-branded NiMH batteries with the S90.
Storage Capacity
The Sony DSC-S90 stores its photos on Memory Stick memory cards or in approximately 32 MB of internal memory, and no card is included with the camera. (I strongly recommend buying at least a 64 MB card, preferably a 128 MB one, to give yourself extra space for extended outings.) The chart below shows how many images can be stored in the internal memory at each size/quality setting.
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Resolution/Quality 32 MB Internal Memory |
Fine | Normal | |
| 2304
x 1728 |
Images (Avg size) |
16 2.0 MB |
29 1.1 MB |
| Approx. Compression |
6:1 | 11:1 | |
| 2048
x 1536 |
Images (Avg size) |
20 1.6 MB |
36 903 KB |
| Approx. Compression |
6:1 | 11:1 | |
| 1280
x 960 |
Images (Avg size) |
49 668 KB |
89 368 KB |
| Approx. Compression |
6:1 | 10:1 | |
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Images (Avg size) |
196 167 KB |
491 67 KB |
| Approx. Compression |
4:1 | 9:1 | |
Download Speed
The Sony DSC-S90 connects to a host computer via a USB interface. Downloading files to my Sony desktop running Windows XP (Pentium IV, 2.4 GHz), I clocked it at 5135 KBytes/second, an almost unbelievably fast rate. (Yes, we did check this a number of times, at it really was that fast.) (Cameras with slow USB interfaces run as low as 300 KB/s, cameras with fast v1.1 interfaces run as high as 600 KB/s. Cameras with USB v2.0 interfaces run as fast as several megabytes/second.)
S90 Test Images
S90 Specifications
S90 "Picky Details"
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