Nikon CoolPix 4500Nikon updates the hugely successful Coolpix 995, adding a full 4.0-megapixel CCD!<<Optics :(Previous) | (Next): Shutter Lag & Cycle Time Tests>> Page 6:Exposure & FlashReview First Posted: 5/29/2002 |
Exposure
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As I've come to expect with Nikon's cameras, both digital and film-based, the
Coolpix 4500 offers extensive, flexible exposure control. A range of exposure
modes are available, including Program, Flexible Program, Aperture Priority,
Shutter Priority, Manual, Auto, and Scene modes. Thanks to a user interface
design that makes extensive use of external buttons and a Command dial, changing
the 4500's modes and exposure settings is very fast, and should only rarely
need to delve into the LCD menu system under normal shooting conditions.
Auto exposure mode puts the camera in charge of everything, with the exception
of flash mode and the image size and quality settings. Scene mode offers 16
preset "scenes" to choose from, each setting up the camera for specific
shooting situations. Scenes include Portrait, Party/Indoor, Night Portrait,
Beach/Snow, Landscape, Sunset, Night Landscape, Museum, Fireworks Show, Close
Up, Copy, Backlight, Multiple Exposure, Panorama, Sports, and Dusk/Dawn. (Panorama
and Multi Exposure are both new to the Coolpix family. The Panorama option is
particularly nicely done, showing you a "ghosted" version of the previous
shot on the LCD as an aid to lining up the next one.) Once Scene mode is selected
by pressing the Mode button and turning the Command dial, the Menu button displays
the available scenes (as well as the image quality and size adjustments). In
Program AE mode, the camera takes control of shutter speed and aperture, while
you adjust the remaining exposure settings. The Flexible Program option goes
a step further by letting you select from a range of valid shutter speed and
aperture combinations, simply by rotating the Command dial while in Program
exposure mode. The camera determines the required exposure, but you can choose
whether it achieves that exposure with a shorter shutter speed and wider aperture,
or a longer shutter speed and smaller aperture. (Simply turn the Command dial
on its own while in Program mode, and an asterisk appears next to the "P"
in the LCD display. Further rotation of the Command dial will cycle through
the available combinations of shutter speed and aperture.) Shutter Priority
lets you select shutter speeds from 1/2,000 to eight seconds, while the camera
selects the appropriate corresponding aperture. Likewise, under Aperture Priority,
you can select the lens aperture while the camera selects the best shutter speed.
Manual mode gives you control over both aperture and shutter speed, but increases
the shutter options to include a Bulb setting for longer exposures (up to five
minutes). In any mode, if the camera's metering system disagrees with your exposure
choices, the shutter and aperture values will display in red to indicate that
this may not be the best exposure option. Important note: The 1/2,300
shutter speed is only available in Auto and Scene exposure modes. Maximum shutter
speed in all other modes is 1/2,000.
Exposure compensation lightens or darkens the overall image by -2 to +2 exposure
equivalents (EV) in one-third increments. Additionally, under the Image Adjustment
option on the settings menu, you can increase or decrease contrast. A Saturation
adjustment offers a range of saturation levels, as well as a Black & White
monochrome mode. The Coolpix 4500 offers a full range of sensitivity settings
including an Auto option, as well as specific ISO equivalents of 100, 200, 400,
and 800 (activated by pressing the Flash / ISO button and rotating the Command
dial). In-camera sharpening is adjustable to Auto, High, Normal, Low or Off
under the Sharpening option of the settings menu.
I mentioned earlier that the Coolpix 4500 has a "bulb" exposure mode
that allows exposures as long as five minutes. This is an exceptionally long
exposure time, but would normally be almost useless due to the amount of CCD
noise that can accumulate in that interval. The 4500 uses a form of "dark
frame subtraction," whereby a second exposure is snapped immediately after
the first, but with the shutter closed. The pattern of noise in this "dark
frame" is then subtracted from the image itself, resulting in a drastic
reduction in apparent noise levels. (I suspect that the actual algorithm is
more complex than simple subtraction though, involving data substitution to
prevent black pixels where the noise current saturated the CCD photosite.)
In my tests of a production model 4500, it performed very well in the low-light arena, capturing bright, clear images at light levels as low as 1/16 foot-candle (0.67 lux) at all ISO settings tested from 100 to 800. Low light focusing was another matter though: Under relatively favorable test conditions, with a high contrast subject, the 4500's autofocus system could only achieve a focus lock in light levels of 1/2 foot-candle (5.5 lux) or above. Anything darker than that, and you'll have to set the focusing distance manually, a task made much more difficult than it might be by the lack of any numeric distance readout while in manual focus mode. Image noise under low light conditions was very low at the lower ISO settings, creeping up slightly with the 400 and 800 ISO settings. The camera's Noise Reduction option was very effective at removing so-called "hot pixel" noise, but has no effect on the random image noise that results from higher ISO settings. (With the Noise Reduction off, the 4500's images showed the amount of noise I'm accustomed to seeing in prosumer digicams at competing price levels. With the Noise Reduction on though, image hot pixel noise was virtually eliminated.
White balance options include a matrix-based Auto setting (meaning it uses color
information from multiple points across the frame to gauge color balance) as
well as Fine (Outdoors), Incandescent, Fluorescent, Cloudy, Speedlight (flash
balanced), and Preset (or Manual). The Preset option lets you set the camera's
white balance to almost any lighting condition, simply by pointing the camera
at a white object and saying (in effect) "make this white." For more
fine-tuned color balance, you can adjust the fixed white balance settings (all
modes except Auto and Preset) from -3 to +3 in arbitrary units, to increase
the warm or cool tones in the image. I really like this white balance adjustment
option, as I often find myself wishing I could "tweak" a camera's
color balance. The step size and range provided on the 4500 are just right in
my opinion, offering fine-grained control, and a reasonably wide range of adjustment.
A White Balance Bracketing option captures a series of three images at different
white balance settings. After the first image is taken at the regular white
balance value, the camera alters the white balance with a reddish tint, and
then a bluish tint. (The adjustments are triggered by each actuation of the
Shutter button, until the series of three images has been taken.)
By default, the Coolpix 4500 employs a 256-segment Matrix metering system, which
divides the image into 256 segments and balances the exposure based on readings
from each segment. Through the Record menu, you can change the metering system
to Center-Weighted, Spot, or Spot AF Area. Center-Weighted metering bases the
exposure on a large area at the center of the image, while Spot metering takes
a reading from the very center, good for high contrast subjects. The Spot AF
Area mode works with the autofocus target system, basing the exposure reading
on the same target location that you've assigned the AF area to (through the
Focus Options sub-menu). You can lock the exposure by pressing the center of
the Multi-Selector button. "AE Lock" appears in the LCD display, and
exposure remains locked until the Shutter button is fully pressed or the Multi-Selector
button is pressed again. (You can also set the Multi-Selector to lock exposure
and focus together.)
Flash
The Coolpix 4500 features a popup flash design, with five flash modes: Auto,
On, Off, Red-Eye Reduction, and Slow-Sync. Through the settings menu, flash
power is adjustable from -2 to +2 exposure equivalents (EV). The Slow-Sync option
is useful when shooting subjects with dark backgrounds (such as night scenes)
because the camera actually leaves the shutter open longer and then fires the
flash before the shutter closes. This allows more ambient light into the image
and can provide a nice motion blur effect. Red-Eye Reduction mode fires a pre-flash
before the main exposure, to reduce the reflection from the subject's pupils.
The 4500's pop-up flash gives it an advantage in the Red-Eye category, as it
provides a little extra separation between the flash and the lens to help avoid
Red-Eye. Keep in mind that the flash is automatically switched off when shooting
in the Infinity focus mode; the Continuous, 16 Shots or VGA Sequence modes;
when using the Best Shot Selector; when using a lens converter; or when the
AE Lock option is on.
An external sync socket means you can connect a more powerful external flash,
and the camera allows both external and internal flashes to work together. (The
socket connects to Nikon Speedlight models SB-80DX, 50DX, 28DX, 28, 26, 25,
24, and 22, using the proprietary three-prong Nikon sync connector.) Simultaneous
with the release of the 4500, Nikon has also announced a new "Macro Cool
Light" accessory, a ring flash unit for macro photography. The external
sync connection provides a "quench" signal to the flash, allowing
the 4500 to control the total light delivered by the external strobe unit. Note
though, that there are limitations here when compared to the flash capabilities
of Nikon's film cameras. First, the flash metering is not TTL (through
the lens). The flash exposure sensor is located in a tiny window next to the
internal flash head. Second, since the external sync connector only transmits
a quench signal to the remote strobe, no distance-feedback information can be
passed, limiting the capabilities of Nikon's high-end speedlights. If you're
planning on buying a high-end Nikon SLR at some point in the future, go ahead
and get the SB-80, 50, or 28DX speedlight. Otherwise, there's relatively little
advantage to buying anything but the least expensive speedlight available.
Continuous Shooting
The Coolpix 4500 offers several "motor drive" rapid-exposure modes
for capturing quick sequences of images. Four modes (Continuous, Multi-Shot
16, Ultra High-Speed Continuous, and Movie) are selectable under the Continuous
option of the settings menu. The Continuous mode captures frames very quickly,
at whatever resolution and image quality the user has selected. Multi-Shot 16
mode subdivides the image area into 16 sections and captures a collage of small
images (568 x 426 pixels), which fills-in a 4x4 array within a single high-resolution
image as the shooting progresses. Ultra High-Speed Continuous mode captures
approximately 30 frames per second, up to about 80 QVGA-sized images (320x240
pixels). Finally, the Movie mode captures up to 35 seconds of moving images
with sound at approximately 15 frames per second (QVGA size). (Sound
recording is one of the new features added to the 4500 over the earlier 995.)
Actual movie times will vary with the amount of available memory card space,
and available recording time appears in the LCD monitor.
Other Features
You can save up to three sets of user settings for focus, exposure, and other
camera options, for rapid recall via the shooting menu. This can be a real time
saver in rapidly switching between widely different sets of shooting conditions.
(Switching between the stadium and locker room for sports coverage? Indoor and
outdoors at a family party? - You get the idea...) The Auto Bracketing feature
brackets five or three steps around the set exposure value while the Best Shot
Select (BSS) snaps several images in rapid succession, with the camera choosing
only the sharpest (least blurred) to be saved. Best Shot Select makes it feasible
to handhold the camera for surprisingly long exposures: I've routinely captured
half-second handheld exposures with Coolpix cameras. You can also check your
own work immediately as the camera gives you a quick preview of the captured
image (when shooting with the LCD monitor) and gives you an option to delete
or save the image (this function can be turned off through the Setup menu, under
Monitor Options). The 4500's Self-Timer offers a three or 10-second countdown
before firing the shutter, allowing you compose images and then jump into the
exposure.
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