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Nikon CoolPix 990 Nikon updates the hugely successful Coolpix 950, with 3.34 megapixels and numerous enhancements Select a topic Reference: Datasheet CoolPix 990 Sample Images --------------------------------- 1. Intro and Highlights 2. Executive Overview 3. Design 4. Viewfinder 5. Optics 6. Exposure & Flash 7. Shutter Lag & Cycle Time Tests 8. Operation & User Interface 9. Camera Modes & Menus 10. Image Storage & Interface 11. Video, Power, Software 12. Test Results & Conclusion --------------------------------- Print-Friendly Review Version Additional Resources and Other Links Reader Comments on CoolPix 990 Review --------------------------------- Digital Camera Comparometer (TM) --------------------------------- <-- Digital Cameras (Home) <-- Digital Camera Reviews Index <<Exposure & Flash :(Previous) | (Next): Operation & User Interface>> Page 7:Shutter Lag & Cycle Time Tests Review First Posted: 3/1/2000

Shutter Lag/Cycle Times
When you press the shutter release on a camera, there's usually a lag time before the shutter actually fires. This time is to allow 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 almost never reported on, and can significantly affect the picture taking experience, we now routinely measure it, using an electronic test system accurate to 0.01 seconds.
The Coolpix 990 autofocus speed is about average, compared to other digicams we've tested (January, 2000), with a shutter lag of 1.13 seconds in full autofocus mode, 0.18 seconds when the lens is prefocused by half-pressing the shutter button, and 0.49 seconds in manual-focus mode. NOTE: Reader Bryan Biggers wrote in to report that a number of 990 owners have consistently measured shutter lag times of under 0.1 seconds in manual-focus mode. Unfortunately, we had already sent our test unit back to Nikon by the time we heard this, so couldn't repeat the test. We're pretty confident of our result though, since we (a) use an electronic test system that really couldn't produce an error of that magnitude, and (b) repeated this particular test several times, since we ourselves were surprised that the manual-focus delay was so long. We stand behind the number we measured, but given Bryan and others' experience, it's entirely possible that a modification was made in later production units. We tested a production model, but obviously one of the first off the line. A firmware change could easily account for this discrepancy. Thanks for the note, Bryan!
Shot to shot cycle time is very good though, at only 1.7 seconds for the first two shots in highest-quality JPEG mode, at which point the buffer memory is full and you have to wait something on the order of 7 seconds or so for it to empty. Lower resolutions increase the number ßof shots you can take in quick succession, and reduce the amount of time you need to wait for the buffer to clear again. At XGA resolution, you can shoot 7 frames at 1.62 second intervals, after which the next two frames will require 3 seconds each. If you continue shooting at maximum speed, the cycle time will alternate between 1.65 and 3.0 seconds indefinitely. We never found a maximum number of frames that filled the buffer in VGA mode, but it's something over 20. Cycle time in VGA mode was 1.65 seconds. (Note that all these cycle times were measured in manual focus mode: Autofocus mode would add about 0.6 seconds to the cycle times, to allow for focus-system operation.
Frame rates in continuous mode also varied as a function of resolution (albeit only slightly), as did the number of exposures we could capture before waiting for the buffer to empty. In high resolution mode, we could capture 3 frames at roughly 1 frame per second. At XGA resolution, we captured 8 frames at 1.62 frames per second. At VGA resolution, we captured 21 frames at 1.72 frames per second. The "VGA Sequence" option captured 40 frames at a rate of 1.76 frames per second. The 16-shot mode captured 16 quarter-resolution frames at a frame rate of 2.0 fps.Ultra high speed mode captured 80 320 x 240 frames at 30 fps (saving the results as individual image files in memory), while the Movie mode also captured 320x240 frames at 30 fps, with the resulting motion sequence saved in a single MOV file. The table below summarizes our cycle-time measurements:

Capture Mode	Interval/ fps	No. of frames
Single-shot, 2048x1536	0.568 sec	2
Single-shot, 1024x768	1.62 sec	7
Single-shot, 640x480	1.65 sec	>20
Continuous Mode, 2048x1536	1.0 fps	3
Continuous Mode, 1024x768	1.62 fps	8
Continuous Mode, 640x480	1.72 fps	21
VGA Sequence	1.76 fps	40
16-Shot Mode (512x328)	2.0 fps	16
Ultra High-Speed Mode (320x240)	30 fps	80
Movie Mode	30 fps	40 secs (w/incl 16MB card)