"Picky Details" for the Kodak EasyShare DX7590 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 Kodak EasyShare DX7590:
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(secs) |
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| Power On -> First shot |
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LCD turns on and lens extends forward. On the fast side of 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. Average lens retraction time, buffer clearing is slow, particularly given that this corresponds to only four large/fine images.
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| Play to Record, first shot |
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Time until first shot is captured. Quite 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. Fairly fast.
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| Shutter lag, full autofocus |
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First time is at full wide-angle, second is full telephoto. 0.5 second is very fast, 1.03 seconds is on the slow side of average but good for a long-zoom lens. (Most cameras have a range from 0.8-1.0 second, although long-zoom models tend to be slower.) |
| Shutter lag, continuous autofocus | 0.55 | Time is with lens at telephoto setting, very fast. (The DX7590's AF system is rather different from that of most cameras. Atypically, shutter lag is quite a bit faster in continuous autofocus mode. Also atypically, continuous AF is the camera's default setting. Where the full-autofocus times are rather lackluster, shutter lag in continuous autofocus mode is quite impressive.) |
| Shutter lag, prefocus |
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Time to capture, after half-pressing shutter button. Very fast.
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| Cycle Time, max/min resolution |
3.6/2.6 |
First number is for large/fine files, second number is time for small/basic images. Times are averages. Only captures two shots this fast, then slows significantly to 8.9 seconds/shot for large/fine files, 7.1 seconds/shot for small/basic ones. Empties the buffer in 18 seconds in large/fine mode, 15 seconds in small/basic mode. On the slow side, and buffer capacity is rather low. |
| Cycle Time, burst mode, max/min resolution | 0.50 (2.00 fps) |
Shoots a burst of four large/fine images or small/basic images at a preset rate of 2 fps. Buffer clears in 40 seconds for large/fine images, 32 seconds for lowest resolution. Pretty fast, but buffer clearing is very slow. |
Shutter lag is fast in the default AF mode, cycle times are on the slow side. With a full-autofocus shutter delay that ranges from 0.53 to 1.03 second, the DX7590's shutter response spans a range from fast to average. (Most consumer digicams have shutter lag in the range from 0.8-1.0 second, which is still too slow, in my opinion.) BUT, unlike most cameras I test, the DX7590's continuous-autofocus mode (its default setting) is a good bit faster, delivering shutter lag times at the telephoto end of the lens' range of only 0.55 seconds, which is a good bit better than the majority of digicams on the market. Shutter delay is very short (0.086 second), when the camera is "prefocused" by half-pressing and holding down the shutter button before the actual exposure. Cycle times are unimpressive, at 3.6 seconds between shots in large/fine mode, and 2.6 seconds in small/basic. The 7590's buffer memory holds only two shots at either size, so the camera slows pretty dramatically after snapping only two images. Continuous-mode performance is quite a bit better, at 2 frames/second, for up to four frames. All in all, good shutter response, especially for a long-zoom camera, it'd just be nice if it had a larger buffer memory in single-shot mode. (Note that this paragraph has been revised from the initial posting of this review. I initially gave the DX7590 poor marks for its shutter lag at telephoto focal lengthts. It turned out that (a) the roughly 2-meter distance I'd shot the telephoto lag tests at was close enough that it resulted in longer AF times, and (b) I was concentrating on normal single-AF mode, when it turned out that the faster continuous-AF mode was in fact the camera's default. In continuous-AF mode, the camera's shutter response is in fact much better than average.)
Power
The Kodak EasyShare DX7590 uses a custom rechargeable LiIon battery for power.
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(@5 volts on the external power terminal) |
(1700 mAh LiIon) |
| Capture Mode, w/LCD |
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| Capture Mode, no LCD |
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| Half-pressed shutter w/LCD |
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| Half-pressed w/o LCD |
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| Memory Write (transient) |
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| Flash Recharge (transient) |
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| Image Playback |
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Very good battery life. With a worst-case run time of almost two and three-quarter hours with the rear LCD illuminated in capture mode, and over four and a half hours of continuous run time in playback mode, the DX7590's battery life is a fair bit better than average. I still recommend purchasing a second battery along with the camera, but more casual shooters may find that the battery supplied with the camera will pack enough power for their usage
Storage Capacity
The Kodak EasyShare stores its photos on SD/MMC memory cards or in approximately
29 MB of internal memory. No memory card is included with the camera. (I strongly
recommend buying at least a 128 MB card, preferably a 256 MB one, to give yourself
extra space for extended outings.) The chart below shows how many images can
be stored in 29 MB of internal memory at each size/quality setting.
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Resolution/Quality 29 MB Internal Memory |
Fine | Normal | |
| 2576 x 1935 | Images (Avg size) |
8 3.5 MB |
17 1.6 MB |
| Approx. Compression |
4:1 | 9:1 | |
| 2304 x 1728 | Images (Avg size) |
10 2.8 MB |
21 1.3 MB |
| Approx. Compression |
4:1 | 9:1 | |
| 2048 x 1536 | Images (Avg size) |
12 2.2 MB |
27 1.1 MB |
| Approx. Compression |
4:1 | 9:1 | |
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Images (Avg size) |
21 1.3 MB |
43 663 KB |
| Approx. Compression |
4:1 | 9:1 | |
Download Speed
The Kodak EasyShare 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 740 KBytes/second, a pretty good pace. (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.)
DX7590 Test Images
DX7590 Specifications
DX7590 "Picky Details"
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