"Picky Details" for the Hewlett Packard Photosmart 945 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 Hewlett Packard Photosmart 945:
|
|
||
|
|
(secs) |
|
| Power On -> First shot |
|
LCD turns on and lens extends forward. A little slow.
|
| Shutdown |
|
First time is time to retract lens, second time is worst-case buffer-clearing time, before you can remove the memory card. First time is fairly fast, buffer clearing is *very* slow.
|
| Play to Record, first shot |
|
Time until first shot is captured. Quite fast.
|
| 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. Fairly fast.
|
| Shutter lag, full autofocus |
|
First time is at full wide-angle, second is full telephoto. On the fast side of average. (Average is 0.8-1.0 seconds, still too slow in my opinion.) |
| Shutter lag, prefocus |
|
Time to capture, after half-pressing shutter button. Very fast.
|
| Cycle Time, max/min resolution |
1.80 / |
First number is for large/fine files, second number is time for "TV" mode (640x480) images. Times are averages. In both modes, shoots this fast for three shots. Large/fine mode then slows to 10 seconds per shot, and takes 33 seconds to clear the buffer. TV mode slows to 9 seconds per shot, and takes 28 seconds to clear the buffer. Cycle times are pretty good, but buffer memory is rather modest by current standards. Buffer clearing times are very slow. |
| Cycle Time, Burst mode, max/min resolution | 0.55 (1.82 fps) |
Both large/fine and "TV" modes shoot at this rate, with the buffer holding 5 large/fine or 6 TV images. Times are averages. Buffer clears in 62 seconds for large/fine images, 52 seconds for lowest resolution, and it's ready for another burst. Fairly fast, but buffer-clearing is very slow. |
With full-autofocus shutter delays of 0.65-1.07 seconds, the PhotoSmart 945 straddles the average range among digicams I test. (The normal range is 0.8-1.0 seconds, still too slow, in my book.) Prefocus delay is very short, only 0.078 seconds. Shot to shot cycle times are about 1.8 seconds regardless of image size, but the buffer memory holds only 3 shots, after which the camera slows to 10 seconds between frames. The buffer memory also takes a long time to clear, 33 seconds in my tests. This was an area that caused me a lot of frustration in the rapid-fire shooting of our testing, but that I was surprised to find wasn't a particular issue when I was more or less shooting snapshots with the camera for its photo gallery. If you're interested in capturing a lot of fast-paced action, the PhotoSmart 945 wouldn't be the camera to choose, but for more casual uses, it should be plenty fast.
Power
The HP 945 uses a four AA batteries for power.
|
|
(@6 volts on the external power terminal) |
|
| Capture Mode, w/LCD |
|
|
| Capture Mode, no LCD |
|
|
| Half-pressed shutter w/LCD |
|
|
| Half-pressed w/o LCD |
|
|
| Memory Write (transient) |
|
|
| Flash Recharge (transient) |
|
|
| Image Playback |
|
|
With a worst-case runtime of nearly two and a half hours on 1600 mAh NiMH AA cells, the PhotoSmart 945's battery life is quite a bit better than average. (And with modern rechargeable NiMH cells with true capacities of 2000 mAh or more, run times would be longer still.) Despite this excellent battery life though, I still strongly recommend purchasing at least two sets of high-capacity NiMH batteries and a good charger, so you'll always have a fully-charge set of spares. Read my Battery Shootout page for actual test results on a variety of batteries, and see my review of the Maha C-204F charger to learn why it's my longtime favorite.
Storage Capacity
The HP stores its photos on SD memory cards, and a 32 MB 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 on the included 32 MB card
at each size/quality setting.
|
Resolution/Quality 32 MB Memory Card |
Fine | Normal |
|
|
| 2,608 x 1,952 | Images (Avg size) |
11 2.8 MB |
24 1.3 MB |
44 719 KB |
| Approx. Compression |
6:1 | 12:1 | 21:1 | |
| 1,296 x 976 | Images (Avg size) |
24 1.3 MB |
52 615 KB |
78 410 KB |
| Approx. Compression |
3:1 | 6:1 | 9:1 | |
Download Speed
The HP 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 548 KBytes/second. This is about as fast as cameras with USB v1.1 interfaces
get. (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.)
Photosmart 945 Test Images
Photosmart 945 Specifications
Photosmart 945 "Picky Details"
Up to Imaging Resource digital cameras area
Follow Imaging Resource: