Casio Exilim EX-750 Review
Timing & Performance
No real complaints at all here - the Z750 is as zippy as you'd hope from a camera in this class in 2005. The important stuff - focus speed, shutter lag, shot-to-shot times and so on are excellent, and overall the camera feels very responsive indeed in use. I'd like to see the flash recycle time cut down a little (when you fire the flash at full power, i.e. from a distance, it can stretch the shot-to-shot time to around 5 seconds), and the burst mode is nothing to write home about, but performance as a whole is very impressive.
All times calculated as an average of three operations. Unless otherwise stated all timings were made on a 3072x2304 Fine JPEG Super Fine image (approx. 3,430 KB per image). The media used for these tests was a 1.0GB SanDisk Extreme III SD card.
|Power: Off to Record||1.3|
|Power: Off to Play||Image displayed||1.1|
|Power: Record to Off||All activity ceased||1.4|
|Power: Play to Off||When buffer is empty, lens retracted||~0.5|
|Power: Play to Off||When buffer is empty, lens extended||1.3|
|Record Review||Image displayed||~0.7|
|Mode: Record to Play||~0.3|
|Mode: Play to Record||Lens already extended||~0.35|
|Mode: Play to Record||Lens not extended||1.3|
|Play: Magnify||To full magnification (8x)||1.8|
|Play: Image to Image||Time to display each saved image||< 0.2|
|Play: Thumbnail view||3 x 3 thumbnails||~0.3|
|Zoom from Wide to Tele||38 to 114 mm (3 x)||1.0|
|Half-press Lag (0->S1)||Wide angle||~0.2|
|Half-press Lag (0->S1)||Telephoto||~0.25|
|Half to Full-press Lag (S1->S2)||LCD live view||<0.1|
|Half to Full-press Lag (S1->S2)||Viewfinder||<0.1|
|Full-press Lag (0->S2)||LCD live view, wide angle||~0.2|
|Off to Shot Taken||LCD live view||~1.4|
|Shot to Shot||Flash off||1.2 *1|
|Shot to Shot||Flash on (with red eye reduction off)||~2.3|
|Shot to Shot||Flash on (with red eye reduction on)||~2.9|
|*1||Shot to shot times vary according to whether the buffer is full or not (in 3072x2304 mode only), so you can usually get 1.2 seconds for the first few frames, but the rate slows after that. On average the shot - to - shot time is around 1.8 seconds.|
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. The media used for these tests was a 1.0GB SanDisk Extreme III SD card. Shutter speed was kept above 1/160 sec during these tests.
Continuous drive mode
The Z750 has a single 'normal' burst mode ('Normal Speed Continuous') that offers speeds of up to 1.5 frames per second at lower resolutions, but only manages around 0.8 fps at the top quality setting (7MP/Fine). With a fast enough card you can shoot in this mode for as long as there's space available. The Z750 disables live preview in burst mode, though a brief post-capture review is shown for each frame as it's taken.
There are two other modes in the drive menu, 'Zoom Continuous', which saves two shots when you press the shutter, one 'normal' (full res) and one zoomed in (reduced resolution). I fail to see the point of this, though I'm sure someone will find one. The second mode, Multi Continuous, takes a single burst of 25 images in a period of around 1.5 seconds, and combines them into a single 1600x1200 frame.
Frames in a burst *1
|3072 x 2304 (7MP) JPEG Fine||Continuous||0.8 fps||unlimited||n/a|
|3072 x 2304 (7MP) JPEG Normal||Continuous||1.25 fps||unlimited||n/a|
|3072 x 2304 (7MP) JPEG Economy||Continuous||1.25 fps||unlimited||n/a|
|2560 x 1920 (5MP) JPEG Fine||Continuous||1.35 fps||unlimited||n/a|
|2560 x 1920 (5MP) JPEG Normal||Continuous||1.45 fps||unlimited||n/a|
|2048 x 1920 (4MP) JPEG Fine||Continuous||1.5 fps||unlimited||n/a|
|1600 x 1200 (2MP) JPEG Fine||Continuous||1.25 fps||unlimited||n/a|
|*1||In a single "burst" (finger held down on shutter release).|
|*2||Once the buffer is full the V700 will pause for between 1.9 and 2.5 seconds before another burst of shots can be taken - most of this time is taken up with the process of autofocus and auto exposure.|
Although the actual frame rate isn't that impressive - certainly not if you want to shoot at the best possible quality setting - the performance is perfectly acceptable at lower size/quality settings, and the buffering is fast enough to enable long sequences (as long as you use a fast card).
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 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 1.0GB SanDisk Extreme III SD card.
Time to store
Time to display
File size *1
Images on a *2
|3072 x 2304 (7MP) JPEG Fine||3.3||< 0.2||3,715 KB||220|
|3072 x 2304 (7MP) JPEG Normal||1.8||< 0.2||1,985 KB||431|
|3072 x 2304 (7MP) JPEG Economy||1.4||< 0.2||945 KB||826|
|2560 x 1920 (5MP) JPEG Fine||1.6||< 0.2||2,230 KB||431|
|2048 x 1920 (4MP) JPEG Fine||1.4||< 0.2||1,665 KB||550|
|1600 x 1200 (2MP) JPEG Fine||1.2||< 0.2||1,060 KB||854|
|*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).|
At around 3.3 seconds to write and process a 3.7MB TIFF image, the Z750 is not the fastest camera in its class (averaging around 1.1 MB/s), but this doesn't seem to affect overall performance too badly in everyday use.