Pentax Optio S5i Review
Timing & Performance
In use the S5i feels very responsive indeed - focus is very fast, shutter lag almost non-existent (Pentax quotes 0.01 seconds, and we're inclined to believe it), playback and menus lightning-quick and overall performance excellent for such a compact camera. Of course it's not all good news - there is a serious blight on the otherwise spotless landscape. It seems the S5i makes little use of buffering, meaning each image must be written to the card before the next one can be taken. For full size/best quality images this means a shot-to-shot time of just over four seconds, stretching to over six seconds if you use the flash in red-eye reduction mode. Switching to 'burst' mode improves things slightly managing a shot every 3.2 secs without flash. It's a shame that an otherwise impressively speedy camera can't do a little better when shooting sequences.
All times calculated as an average of three operations. Unless otherwise stated all timings were made on a 2560 x 1920 Fine JPEG image (approx. 1,985 KB per image). The media used for these tests was a 512MB SanDisk Extreme (aka Ultra II) SD card.
|Power: Off to Record||2.3|
|Power: Off to Play||Image displayed||1.3|
|Power: Record to Off||All activity ceased||2.1|
|Power: Play to Off||Lens already extended, buffer empty||1.8|
|Power: Play to Off||Lens not extended, buffer empty||0.5|
|Record Review||Image displayed||~0.7|
|Mode: Record to Play||~0.5|
|Mode: Play to Record||Lens already extended||~0.5|
|Play: Magnify||To full magnification (4x)||1.0|
|Play: Image to Image||Time to display each saved image||~0.1|
|Play: Thumbnail view||3 x 3 thumbnails||~0.4|
|Zoom from Wide to Tele||35 to 105 mm (13 x)||1.2|
|Half-press Lag (0->S1)||Wide angle||~0.5|
|Half-press Lag (0->S1)||Telephoto||~0.7|
|Half to Full-press Lag (S1->S2)||LCD live view||<0.05 *1|
|Half to Full-press Lag (S1->S2)||LCD off||<0.05 *1|
|Full-press Lag (0->S2)||LCD live view, wide angle||0.4|
|Off to Shot Taken||LCD live view||~3.0|
|Shot to Shot||Flash off||4.2|
|Shot to Shot||Flash on (anti red-eye off)||5.5|
|Shot to Shot||Flash on (anti red-eye on)||6.2|
Lag Timing Definitions
|Half-press Lag (0->S1)
Many digital camera users prime the AF and AE systems on their camera by half-pressing the shutter release. This is the amount of time between a half-press of the shutter release and the camera indicating an auto focus & auto exposure lock on the LCD monitor / viewfinder (ready to shoot).
|Half to Full-press Lag (S1->S2)
The amount of time it takes from a full depression of the shutter release button (assuming you have already primed the camera with a half-press) to the image being taken.
(Take shot, AF/AE primed)
|Full-press Lag (0->S2)
The amount of time it takes from a full depression of the shutter release button (without performing a half-press of the shutter release beforehand) to the image being taken. This is more representative of the use of the camera in a spur of the moment 'point and shoot' situation.
(Take shot, AF/AE not primed)
The tables below show the results of our continuous shooting test, indicating the actual frame rate along with maximum number of frames and how long you would have to wait after taking the maximum number of frames before you could take another shot. Media used for these tests was a 512MB SanDisk Extreme (aka Ultra II) SD card. Shutter speed was kept above 1/100 sec during these tests.
Continuous drive mode
In burst mode the S5i shows a brief live preview on-screen (provided you are using the LCD monitor). It offers a single continuous shooting mode, and the length of each burst (how many pictures you can take) is limited only by the amount of space on the memory card. The speed you can shoot at depends on the size/quality setting used and the speed of the card.
Frames in a burst *1
|2560 x 1920 JPEG Fine||Burst||0.32 fps||n/a||n/a|
|2560 x 1920 JPEG standard||Burst||0.35 fps||n/a||n/a|
|2560 x 1920 JPEG basic||Burst||0.58 fps||n/a||n/a|
|2048 x 1536 JPEG Fine||Burst||0.58 fps||n/a||n/a|
|1600 x 1200 JPEG Fine||Burst||0.65 fps||n/a||n/a|
|1924 x 768 JPEG Fine||Burst||0.77 fps||n/a||n/a|
|*1||In a single "burst" (finger held down on shutter release).|
|*2||The S5i can continue to shoot in burst mode indefinitely as long as you have space on the card.|
Although it's nice to be able to keep shooting indefinitely, the S5i's burst mode is hardly something to write home about, managing only one shot every 3.2 seconds at the highest quality setting (5MP/fine). Even dropping to 1.5MP only decreases the gap between shots to around 1.3 seconds, which is frankly disappointing. Note that using a slower card reduces the speed even farther.
File Write / Display and Sizes
Timings shown below are the time taken for the camera to process and 'flush' the image out to the storage card, the timer was started as soon as the shutter release was pressed and stopped when the activity indicator went out. This means the timings also include the camera's processing time and as such are more representative of the actual time to 'complete the task'. The media used for these tests was a 512MB SanDisk Extreme (aka Ultra II) SD card. .
Time to store
File size *1
Images on a *2
|2560 x 1920 JPEG Fine||~3.5||~0.7||2,990 KB||150|
|2560 x 1920 JPEG standard||~2.6||~0.7||1,530 KB||291|
|2560 x 1920 JPEG basic||~2.2||~0.7||886 KB||495|
|2048 x 1536 JPEG Fine||~2.6||~0.7||1,891 KB||247|
|1600 x 1200 JPEG Fine||~2.0||~0.7||1,184 KB||412|
|1924 x 768 JPEG Fine||~1.9||~0.7||551 KB||900|
|*1||All file sizes are an average of three files. As is the case with JPEG it's difficult to predict the size of an image because it will vary a fair amount depending on the content of the image (detail and noise).|
With write times averaging around 3.5 seconds for a 5MP Fine JPEG the S5i is hardly the fastest camera in its class - managing approximately 850KB/s. The relatively slow write speed, combined with the small buffer (which appears to be only big enough to hold a single 5MP fine JPEG) explains the lengthy shot-to-shot times.