(Timing, Power, and Storage Info)
Timing
Since they're rarely reported on but very important to the picture-taking experience,
I measure both cycle times and shutter delay times for all the cameras I review,
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
Minolta DiMAGE Z1 digicam:
NOTE: My qualitative characterizations of camera performance below (that
is, "reasonably fast," "about average," etc.) are
meant to be relative to other cameras of similar price and general capabilities.
Thus, the same shutter lag that's "very fast" for a low-end
consumer camera might be characterized as "quite slow" if I
encountered it on a professional model. The comments are also intended
as only a quick reference: If performance specs are critical for you,
rely on the absolute numbers to compare cameras, rather than my purely
qualitative comments.
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(secs) |
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| Power On -> First shot |
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Time from power-up to first shot captured. Faster than
average for a camera with a telescoping lens.
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| Shutdown |
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Time for lens to retract. About average.
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| Play to Record, first shot |
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Time until first shot is captured. Pretty fast.
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| Record to play |
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Time to display an image immediately after capture.
First number is for maximum resolution, second is for minimum. Both
times are fairly fast.
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| Shutter lag, full autofocus |
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First time is for wide-angle, second is for telephoto. Unusual in that the wide-angle delay is longer than that for telephoto, but both numbers are faster than average. (Unusual in a long-zoom digicam.) |
| Shutter lag, continuous autofocus | 0.524 | Not a significant improvement over normal autofocus with stationary subjects (as with my test target), but may help with moving subjects. |
| Shutter lag, manual focus |
0.312
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Averate to a bit faster than average. |
| Shutter lag, prefocus |
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Time to capture, after half-pressing Shutter button.
Much (!) faster than average.
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| Cycle Time, max/min resolution |
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First number is for maximum resolution, fine-quality files, second number is time for minimum res, normal-quality. Both are quite fast. At max res, the camera shoots this fast for the first five frames, then drops to an average cycle time of 3.15 seconds, still quite good. At small/normal resolution the camera can shoot a great many files without waiting for the memory card to catch up. |
| Cycle Time, continuous mode | 0.67 (1.50 frames/sec) |
No difference in continuous mode cycle time for large or small files. First shot in all size/quality settings takes 0.8 seconds, then subsequent ones take 0.67. Roughly 5 large/fine shots held in buffer before the camera slows to ~2.55 seconds per shot. (Still pretty fast.) At small/basic quality setting, buffer holds ~90+ frames. Buffer takes 15-20 seconds to clear with large/fine files, up to 80 seconds with small/basic. |
| Cycle Time, high-speed continous mode | 0.1 (10 frames/sec) |
10 frames in series, then must wait ~11 seconds for buffer to clear. Very fast. Resolution automatically set to 1280x960. |
Based on the results above, the Z1 shows itself to be a pretty fast camera.
Shutter lag is quite a bit better than average, particularly when compared
with other long-zoom digicams, and cycle times are quite good as well, with
a healthy 5-shot buffer capacity in large/fine resolution/quality mode. Prefocus
shutter lag is amazingly fast, at only 0.09 seconds. Continuous-mode speed
is fair in normal continuous mode, but very fast in the high-speed continuous
mode. (Note that high-speed continuous mode automatically sets the resolution
to 1280x960, but that's larger than the image sizes permitted by many cameras
high-speed options. With its long-ratio zoom lens and fast shooting, the Z1
would be a natural choice for sports and other action photography.
Power
The Z1 uses four AA batteries for power, either alkaline or NiMH types.
The Z1 offers an Auto Power Save option through the Setup menu, which lets you
specify how long the camera will wait without user input before shutting itself
off, with options ranging from 1 to 10 minutes. Because the Z1 uses the same
LCD panel for both the rear panel and eyelevel viewfinder, using the EVF saves
almost no power relative to the level consumed when using the rear panel display.
As always, I suggest picking up a couple of sets of rechargeable NiMH batteries,
and keeping a spare set freshly charged at all times. (See my Battery
Shootout page for actual test data of high-power NiMH cells currently on
the market.)
As usual, I measured the Z1's actual power consumption in various operating modes, and projected run times based on a set of 1600 mAh rechargeable NiMH batteries. (This is the standard battery capacity I've used for AA-equipped digicams since I started tracking power consumption. Modern high-capacity cells are available with true (not claimed) capacities of 2000 mAh or higher. Using such cells would boost the run times shown here by about 25%.) The results of my testing appear in the table below:
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(@ 6 v) |
(1600mAh, 4.8v 4 AA Cells) |
| Capture Mode, rear panel LCD |
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| Capture Mode, eyelevel LCD |
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| Half-pressed shutter, rear panel LCD |
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| Half-pressed shutter, eyelevel 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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Overall, the DiMAGE Z1 shows much better than average battery life. (As witness
the fact that all the times in the table above are in hours, not minutes.) I
still strongly recommend purchasing two sets of high-power NiMH cells, keeping
a spare set charged at all times, but the Z1 really leads the field among long-zoom
digicams in terms of battery life. (As an added bonus, when the camera goes
to "sleep" when left in capture mode for an extended period with no
activity, the power drops almost to zero, yet the camera still wakes up and
is ready to take a picture again quite quickly.)
Storage Capacity
The DiMAGE Z1 stores its images on cards, and a 16 MB card is packed with
the camera. As always, I strongly recommend buying at least a 32MB card,
preferably a 64MB one, to give yourself extra space for extended outings. The
chart below shows how many images can be stored on the included 16MB card at
each size/quality setting, and the approximate amount of image compression applied
in each mode. (The more image compression that's applied, the smaller the image
files, but the lower quality the photos will be.)
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Resolution/Quality 16 MB Memory Stick |
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Normal |
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| Full Resolution 2,048 x 1,536 | Images (Avg size) |
9 1,662 KB |
18 865 KB |
34 465 KB |
| Approx. Compression |
6:1 | 11:1 | 20:1 | |
| 1,600 x 1,200 | Images (Avg size) |
1,049 KB |
29 548 KB |
315 KB |
| Approx. Compression |
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11:1 |
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Images (Avg size) |
23
681 KB |
41 382 KB |
74
216 KB |
| Approx. Compression |
5:1
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10:1 |
17:1
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640 x 480
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Images (Avg size) |
216 KB |
107 149 KB |
100 KB |
| Approx. Compression |
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6:1 |
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Download Speed
The DiMAGE Z1connects to a host computer via a USB interface. Unfortunately,
the prototype Z1 I based this first-look review on didn't have its USB interface
properly enabled yet, so I wasn't able to measure its download speed. (I'll
try to get back to this and measure the download speed once I receive a production
model to test.)
Z1 Test Images
Z1 Specifications
Z1 "Picky Details"
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