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Pentax Optio 450
"Picky Details" for the Pentax Optio 450 digital camera
(Timing, Power, and Storage Info)
Timing
I measure both cycle times and shutter delay times, 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 Optio 450:
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.
|
Optio 450 Timings
|
|
Operation
|
Time
(secs)
|
Notes
|
| Power On -> First shot |
9.65
|
Lens extends, startup screen displays. Very slow,
for some reason quite a bit slower than the 550.
|
| Shutdown |
4.02
|
Lens retracts somewhat more slowly than average.
|
| Play to Record, first shot |
1.00
|
Time until first shot is captured. Quite fast.
|
| Record to play |
5.42/1.23
|
Time to display a large/fine file after capture. First
time is immediately after capture, second time is after camera has finished
writing the image to the memory card.
|
| Shutter lag, full autofocus |
1.16/1.18
|
First time is for wide angle, second is
for telephoto lens setting. Both are just on the slow side of average.
(Average is between 0.8 and 1.0 seconds.) |
| Shutter lag, manual focus |
0.419
|
Time to capture in manual focus mode. A bit faster than
average. (Average is about 0.5 seconds.) |
| Shutter lag, prefocus |
0.131
|
Time to capture, after half-pressing shutter button.
Faster than average. (Average for prefocus lag used to be 0.3 seconds,
these days is more like 0.18 or so.)
|
| Cycle Time, max/min resolution |
1.87/1.93
|
First number is for large/fine files,
second number is time for small/basic images. Pretty fast for a 4 megapixel
camera. The buffer holds 3 to 5 large/fine frames (depending on the subject
matter and how well the images compress) before the camera has to wait
for the memory card. In small/basic mode, the camera writes to the card
as it goes along, so the cycle time never slows. At the large/fine setting,
the cycle time slows to 3.6 seconds after the buffer fills. |
| Cycle Time, continuous mode, max/min resolution |
0.84/0.78
1.19/1.29 fps
|
Top numbers are cycle times for large/fine and small/basic
files. Numbers beneath are corresponding frames per second. The camera
captured three frames in large/fine mode before slowing, and 100+ in small/basic
mode. Once the buffer was full, it took 16 seconds for it to clear after
a large/fine sequence, 60 seconds after the small/fine. |
The Optio 450 is a bit of a mixed bag when it comes to speed, as it starts
up and shuts down somewhat slowly, and it's full-autofocus shutter lag time
isn't too impressive. On the other hand, it's quite a bit faster than average
from shot to shot, and has a decent buffer memory, with room for 3-5 frames
at its maximum image size and quality setting. It's prefocus shutter lag is
quite fast as well. Continuous-mode cycle times are a little sluggish given
how fast it is in other modes, but still aren't too bad. Overall, a pretty fast
little camera, particularly in prefocus mode and from shot to shot.
Power
The Optio 450 uses a single (fairly hefty) lithium-ion battery pack for
its power source. The table below shows the Optio's power consumption in various
modes, and approximate run times for each, based a single lithium-ion battery
pack with a (true, not advertised) 1800 mAh capacity:
|
Operating Mode
|
Power
(@4.5 volts on the external power terminal)
|
Est. Minutes
(3.7 1800 lithium-ion pack)
|
| Capture Mode, w/LCD |
862 mA
|
103
|
| Capture Mode, no LCD |
703 mA
|
126
|
| Half-pressed shutter w/LCD |
1022 mA
|
87
|
| Half-pressed w/o LCD |
820 mA
|
108
|
| Memory Write (transient) |
696 mA
|
n/a
|
| Flash Recharge (transient) |
1690 mA
|
n/a
|
| Image Playback |
406 mA
|
219
|
These are better than average run times for a relatively compact
digicam. I'd still strongly recommend purchasing a second battery along with
the camera though, as digicam batteries invariably run out at the worst possible
moment.
Storage Capacity
The Optio 450 stores its photos on SD/MMC memory cards, and a 16MB card
is included with the camera. (I strongly recommend buying at least a
64MB card or larger, given the 450's four-megapixel maximum resolution and conservative
JPEG compression ratios.) The chart below shows how many images can be stored
on the included 16MB card at each size/quality setting.
Image Capacity vs
Resolution/Quality
16 MB Memory Card
|
Fine
|
Normal
|
Basic
|
|
2,288 x 1,712 |
Images
(Avg size) |
6
2,639 KB |
11
1,384 KB
|
16
962KB |
Approx.
Compression |
5:1 |
9:1
|
12:1 |
| 1,600
x 1,200 |
Images
(Avg size) |
12
1,261 KB
|
21
749 KB
|
29
548 KB
|
Approx.
Compression |
5:1
|
8:1
|
11:1
|
|
1,024 x 768
|
Images
(Avg size) |
26
598 KB
|
48
332 KB
|
60
266 KB
|
Approx.
Compression |
4:1
|
7:1
|
9:1
|
|
640 x 480
|
Images
(Avg size) |
56
282 KB
|
87
183 KB
|
107
149 KB
|
Approx.
Compression |
3:1
|
5:1
|
6:1
|
Download Speed
The Optio 450 connects to a host computer via a USB interface. Downloading
files to my Sony VAIO desktop, 2.4 GHz Pentium IV, running Windows XP, I clocked
it at 611 KBytes/second. (Cameras with slow USB v1.1 interfaces run as low
as 300 KB/s, cameras with fast ones run as high as 600 KB/s. Cameras with
USB v2.0 interfaces range from 600 KB/s to 3 MB/s or higher.)
|
