Timing & Performance
The Z740 generally feels pretty responsive for what is in effect a 'budget' model. That said, there are some aspects of its performance that feel almost painfully slow compared to much of the competition - particularly when attempting to shoot several pictures consecutively, when the very slow buffer clearing (see bottom of the page) means you end up staring at a blue screen with the word 'processing' when you want to be taking pictures. Power-up also feels a bit leisurely at 3.7 seconds, meaning you need to leave the camera on if you want to avoid missing grabbed shots. Focus speed is fine unless you're shooting at the very long end of the lens in low light, when it can stretch to the best part of two seconds before focus is found. At the wide end of the zoom, and whenever there is plenty of light, focus speeds are broadly comparable with other more expensive 'super zoom' cameras.
All times are calculated as an average of three operations. Unless otherwise stated all timings were made on a 2576 x 1932 JPEG image (approx. 950 KB per image). The media used for these tests was a 1.0GB SanDisk Extreme III SD card.
|Power: Off to Record||3.7|
|Power: Off to Play||cannot power up directly into playback mode||n/a|
|Power: Record to Off||All activity ceased||2.9|
|Power: Play to Off||When buffer is empty, lens extended||2.8|
|Record Review||Image displayed||~0.9|
|Mode: Record to Play||~0.75|
|Mode: Play to Record||Lens already extended||~0.9 *1|
|Play: Magnify||To full magnification (8x)||1.5 *2|
|Play: Image to Image||Time to display each saved image||~0.2|
|Play: Thumbnail view||3 x 3 thumbnails||0.9|
|Zoom from Wide to Tele||38 to 380 mm (10 x)||2.1|
|Half-press Lag (0->S1)||Wide angle||~0.4|
|Half-press Lag (0->S1)||Telephoto||~1.0 - 1.6 *3|
|Half to Full-press Lag (S1->S2)||LCD live view||~0.15|
|Half to Full-press Lag (S1->S2)||Viewfinder||~0.15|
|Full-press Lag (0->S2)||LCD live view, wide angle||~0.6|
|Off to Shot Taken||LCD live view||~4.7|
|Shot to Shot||Flash off||1.5 *4|
|Shot to Shot||Flash on (with red eye reduction off)||1.6 *4|
|Shot to Shot||Flash on (with red eye reduction on)||2.4*4|
|*1||This figure increases if the lens was at maximum zoom before switching to review mode, when it can take up to 4.5 seconds to switch back to record. No idea why.|
|*2||This figure does not include the time taken for the Z740 to load the full resolution JPEG (it uses screen res previews for fast scrolling). If this time is included the time increases to 2.0 seconds.|
|*3||Due to the wide variation in focus times at telephoto we have included a range, rather than an average figure. The average was 1.1 seconds|
|*3||This includes focus time and is the very best shot-to-shot time you can expect when the buffer is empty (up to around 5 frames). Shooting at this speed doesn't give the Z740 chance to display a preview image after the first shot - if you wait for the live preview to return you need to add around 1.0 seconds to each figure. Note also that once the buffer is full (5 shots) the times stretch to many seconds.|
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 1/125 sec during these tests.
Continuous drive mode
The Z740 has two 'burst' modes. The standard mode shoots up to 5 frames in a burst at around 2fps (in our tests 4 was the maximum on most occasions), or you can choose 'Last Burst' mode, which takes up to 30 pictures in a 15 second burst, but only saves the last five. The Z740 does not show a preview image during bursts (it does, however, show a brief review image).
Frames in a burst *1
|2576 x 1932 (5MP) JPEG||Burst||2.0 fps||5||~38s delay *3|
|2304 x 1728 (4MP) JPEG||Burst||2.0 fps||5||~38s delay *3|
|2048 x 1536 (3MP) JPEG||Burst||2.0 fps||5||~38s delay *3|
|*1||In a single "burst" (finger held down on shutter release).|
|*2||Once the buffer is full the Z740 freezes for around 7 seconds, displaying the word 'processing' as the images are saved to the SD card. During this time no further pictures can be taken.|
|*3||You can take another single shot about every 7 seconds after a burst - the figure shown is the time taken to completely clear the buffer, after which time you can take another burst of 5 shots.|
Although 2 frames per second - albeit only for 5 shots - is fairly respectable for a budget 5MP camera, the unbelievably slow buffering makes this feature one you need to use with care. In most cases you're looking at a delay of at anything from 6 to 8 seconds before you can take another shot, and it's a full 38 seconds before the buffer is completely emptied and you can take another burst. If you like to snap quickly you'll soon tire of the endless freezes and seemingly interminable 'processing' screen.
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
|2576 x 1932 (5MP) JPEG||~7.2||~0.2||950 KB||632|
|2304 x 1728 (4MP) JPEG||~8.3||~0.2||760 KB||777|
|2048 x 1536 (3MP) JPEG||~8.0||~0.2||620 KB||962|
|1152 x 1164 1.8MP) JPEG||~6.5||~0.2||392 KB||1554|
|*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).|
Here we see the problem with the Z740 - around seven and a half seconds to process and store a 950KB file gives a net write speed of just over 130KB/s... which is very slow indeed. There's no doubt that Kodak is doing some pretty heavy processing to the files as they are saved (including noise reduction), but in a camera that is otherwise fairly snappy, it's a real pity the performance falls so badly at the last hurdle. You won't notice this if you shoot at intervals of more than about 7 or 8 seconds, but if you're trying to keep up with the action and take a lot of pictures, this simply isn't the camera for you.