Timing & Performance
Aside from a rather leisurely start-up time and extended shot-to-shot time in anti-red-eye flash mode, the Coolpix 7900 feels pretty responsive in use, and rarely keeps you waiting to perform any task. A look at the measurements below show the 7900 is pretty fast, though by no means the best performer in its class (in almost all aspects the Canon SD500, for example, is measurably quicker).
Timing Notes
All times calculated as an average of three operations.
Unless otherwise stated all timings were made on a 3072 x 2304 FINE JPEG
image (approx. 2,078 KB per image). The media used for these tests was
a 1.0GB SanDisk Extreme III
SD card.
| Action |
Details |
Time,
secs |
| Power: Off to Record |
|
4.4*1 |
| Power: Off to Play |
Image
displayed |
5.6 *2 |
| Power: Record to Off |
Lens retracted and all activity ceased |
2.2 |
| Power: Play to Off |
When buffer is empty, lens already retracted |
~0.9 |
| Power: Play to Off |
When buffer is empty, lens extended |
~2.7 |
 |
| Record Review |
Image
displayed |
~0.5 |
| Mode: Record to
Play |
|
~1.0 |
| Mode: Play to Record |
Lens already extended |
1.6 |
| Mode: Play
to Record |
Lens
not extended |
2.2 |
|
| Play: Magnify |
To
full magnification (10x) |
3.0 |
| Play: Image to Image |
Time to display each saved image (low res) |
~0.2 |
| Play: Image to Image |
Time to display full res image (allows zooming) |
1.0 |
| Play: Thumbnail view |
2
x 2 thumbnails |
~0.7 *3 |
| Action |
Details |
Time,
seconds |
| Zoom from Wide to
Tele |
38
to 114 mm (3 x) |
0.9 |
| Half-press Lag (0->S1) |
Wide
angle |
~0.55 |
| Half-press Lag (0->S1) |
Telephoto |
~0.75 |
| 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 |
~0.6 - 0.9 |
| Off to Shot Taken |
LCD live view |
4.8 |
| Shot to Shot |
Flash off |
2.0 |
| Shot to Shot |
Flash on |
2.4 |
| Shot to Shot |
Flash on (red eye mode) |
6.0 |
| *1 |
Startup time can be reduced to around 2.1 seconds by disabling the startup animation |
| *2 |
The 7900 can be powered up directly into playback mode by holding the play button for around a second. This figure includes the delay before the camera turns on (designed to avoid accidental activation). |
| *3 |
You can also view 3x3 thumbnails by pressing the zoom button a second time. This adds around 0.9 seconds to the time taken. |
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).
|
(Prime AF/AE) |
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) |
Continuous mode
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 1.0GB SanDisk Extreme III
SD card. Shutter speed was kept above 1/100 sec during these tests.
A 5-shot buffer mode offers around 1 frame per second at the top (7MP Fine) setting, but only saves the last five frames captured (when you take your finger off the shutter button). There does not seem to be a limit to how long you can shoot for in this mode, though of course you'll still only get five shots. Finally, a 16-shot 'burst mode' captures 16 small images in a single 7 megapixel file (in a 4x4 grid) over a period of around 9 seconds.
Continuous drive mode
In burst mode the Coolpix 7900 shows a brief review image for each frame taken. Focus and exposure are fixed with the first frame.
| Image Type |
Mode |
Avg. frames
per sec |
Frames in a
burst *1 |
After
burst *2
|
| 3072 x 2304 JEPG Fine |
Continuous |
1.54 fps |
21 |
0.3 fps |
| 3072 x 2304 JPEG Normal |
Continuous |
1.55 fps |
44 |
0.3 fps |
| 3072 x 2304 JPEG Basic |
Continuous |
1.54 fps |
100 + |
n/a *3 |
| 2592 x 1944 JEPG Fine |
Continuous |
1.57 fps |
100 + |
n/a *3 |
| 1600 x 1200 JPEG Fine |
Continuous |
1.6 fps |
100 + |
n/a *3 |
| *1 |
In a single "burst" (finger held down on shutter release) until the buffer is full. |
| *2 |
With the shutter release held down it is possible to continue shooting after the initial burst at around one frame every 4.4 seconds, though the camera re-focuses between each frame. The buffer takes around 100 seconds to completely clear if you want to shoot another full burst. |
| *3 |
With a fast card it is impossible to fill the buffer at the 7MP/Basic setting and below, meaning to all intents and purposes you can keep shooting until the card is full. |
Not the fastest burst rate in the world, but one that shows the 7900 has a large, fast buffer, allowing you to keep shooting - even at 7 million pixels - for at least 21 frames (and until the card is full at most file size/quality settings).
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.
| Image Type |
Time
to store
(secs) |
Time
to display
(secs) *3
|
File
size *1
(approx.) |
Images
on a *2
1.0 GB Card |
| 3072 x 2304 JEPG Fine |
2.4 |
~0.2 |
2,080 KB |
286 |
| 3072 x 2304 JPEG Normal |
2.3 |
~0.2 |
1,110 KB |
568 |
| 3072 x 2304 JPEG Basic |
2.0 |
~0.2 |
615 KB |
999 |
| 2592 x 1944 JEPG Fine |
2.4 |
~0.2 |
1,475 KB |
399 |
| 1600 x 1200 JPEG Fine |
2.3 |
~0.2 |
918 KB |
632 |
| *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). |
| *2 |
Camera estimation. |
| *3 |
The 7900 uses low res thumbnails to speed up playback of images. Scrolling through images is therefore almost instantaneous. If you want to do anything to a displayed image (crop, zoom etc), you need to wait around 0.9 seconds (all file size/quality settings) for the full resolution file to load. |
Although the buffer is large enough for you to rarely experience any delay, the Coolpix 7900 is more pedestrian when it comes to writing the data to the SD memory card (2.4 secs for a 2,080 KB file equates to around 870 KB/s - hardly taxing the capabilities of our fast card).
|
