Olympus C-5000 Zoom(none)<<Optics :(Previous) | (Next): Shutter Lag & Cycle Time Tests>> Page 6:Exposure & FlashReview First Posted: 11/04/2003 |
Exposure
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Like other Olympus C-Series digicams, the C-5000 Zoom offers a lot of
exposure control, including Auto, Program, Aperture Priority, Shutter Priority,
and Manual exposure modes. Additional exposure options include four ISO settings
(Auto, 50, 80, 160, and 320); exposure compensation up to +/- 2 EV, auto bracketing,
internal and external flash adjustment, and spot or multizone metering, in addition
to a handful of other creative image settings.
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In Auto mode, the camera is in charge of the exposure entirely. The user can only adjust the optical and digital zoom, drive mode, or access the Self-Timer and Macro modes. In Program mode, the camera selects both the aperture and shutter speed (to a maximum of one second), while you control the remaining exposure options such as ISO, Exposure Compensation, White Balance, and metering mode. Aperture Priority lets you set the aperture from f/2.8 to f/8.0, while the camera chooses the best corresponding shutter speed, to a maximum exposure time of one second. In Shutter Priority, you can select shutter speeds from 1/1,000 to four seconds, and the camera selects the best corresponding aperture setting. (Note that in program and aperture-priority modes, the default "Auto" setting of the flash will restrict the maximum exposure time to between 1/20 and 1/100 seconds. Slower shutter speeds will only be available if you either turn off the flash, or set it to slow sync mode.)
In Manual mode, you control both aperture and shutter speed (which can extend to 16 seconds in this mode). In Manual mode, the exposure compensation display at the top of the LCD screen changes into an exposure meter, a helpful feature. As you scroll through various shutter speed/aperture combinations, the camera indicates whether or not it thinks the current setting will give you a correct exposure. It does this by showing the f/stop and shutter speed in green, and the difference between your settings and the "correct" exposure in white numerals, across a range of +/- 3 EV. If the differential exceeds 3 EV, the numbers turn red and stay fixed at a +/- 3 EV reading.
In addition to the five basic exposure modes, a "My Mode" option lets you save a set of exposure settings that can be accessed via the virtual mode dial. Thus, if you shoot under the same conditions frequently, you can save the settings and instantly recall them when needed. This can be very handy when you shoot frequently under the same conditions, such as in an office environment or any place where the lighting is controlled and constant.
Six Scene Program stops on the Mode dial offer preset modes for specific shooting situations. Included are Movie (described shortly), Self-Portrait, Night Scene, Landscape / Scene, Landscape / Portrait, Sports, and Portrait modes. Self-Portrait mode lets you take a picture of yourself by holding the camera in front of you. Night Scene mode optimizes the camera for darker shooting situations, keeping the exposure under automatic control but adjusting the ISO and shutter speed for the best exposure. The two Landscape modes are set up for capturing broad vistas of scenery with or without people in the foreground. In Sports mode, the exposure system is biased toward faster shutter speeds to freeze the action, while Portrait mode sets up the camera to capture individual portraits with wider aperture settings, leaving the subject in crisply focused in front of a slightly blurred background.
Two metering systems are available on the C-5000 Zoom: Spot and ESP multi-segment metering. Spot and ESP are accessed by pressing the Spot / Macro / Print button on the camera's back panel. Under the default ESP multi-segment setting, the camera takes readings from a number of areas across the field of view, and evaluates both brightness and contrast between the areas to determine the best exposure. Spot metering reads the exposure from the very center of the image, so you can pinpoint the specific area of the subject you want properly exposed and lock in on that exposure (as well as the lens focus setting) by depressing the Shutter button halfway and holding it down while you recompose the scene. The AE Lock button also lets you lock exposure independently of focus, simply by pressing the button a single time. The exposure is then locked until the button is pressed again or the Shutter button is pressed.
In the main exposure modes (Program, Aperture Priority, Shutter Priority, and Manual modes), the C-5000 Zoom provides a range of ISO (light sensitivity) settings, including Auto, 50, 80, 160, and 320 ISO equivalents. Higher ISO settings naturally bring along with them higher levels of image noise, but I found the pattern of the C-5000's noise to be unusually tight and fine-grained, making it less objectionable than that of many competing models.
Camera light meters assume that the world averages out to a medium gray, and make their exposure decisions accordingly. This works well most of the time, but subjects that are very bright or dark overall can trick the metering system. Light subjects will tend to be underexposed, while dark ones can be overexposed. In these situations, you need to be able to adjust the camera's default exposure to compensate for the subject's overall tone. This is the function of the "exposure compensation" adjustment. To adjust the exposure compensation on the C-5000 Zoom, simply press either the right or left Arrow buttons (in any exposure mode except Manual) to increase or decrease the exposure values (EV) in one-third-step increments, up to +/- 2 EV. The current compensation setting is displayed in the upper right corner of the LCD. (The LCD viewfinder must be enabled to adjust this setting, but once it is set, you can turn the LCD off to conserve power, and the setting will remain in effect.)
Sometimes you aren't sure how best to adjust the exposure for a given subject, and don't want to take the time to adjust the exposure compensation manually. (The subject might move or go away while you're fiddling with the camera's controls.) The answer to this dilemma is found in the C-5000's Auto Bracketing (BKT) function. Selected through the Shooting Mode Menu, this feature makes the camera automatically "bracket" the exposure for each shot by as much as +/- 2 EV in either three- or five-step increments (0.3, 0.6, or 1.0 EV units each). For example, with a setting of five 0.3 EV steps, the camera will automatically snap five shots, at exposure adjustments of -0.7, -0.3, 0, +0.3, and +0.7 EV, insuring that at least one shot would be exposed just right. The bracketing function centers its efforts around whatever exposure you've previously selected as the starting point, including any exposure compensation adjustments you've made.
White Balance is also set in the Mode Menu, with Auto, One Touch (Manual), or one of six Preset options: Daylight, Overcast, Tungsten, Daylight Fluorescent, Neutral Fluorescent, or Cool Fluorescent, to accommodate a variety of lighting situations. In One Touch mode, white balance is calculated by placing a white card in front of the lens and pressing the OK button. You can also fine-tune the white balance setting with the "WB+/-" setting under the Picture submenu. An adjustment bar appears on the LCD screen, with options to increase or decrease the red or blue tones. (I really like this idea of fine-tuning the white balance. Most digicams tend to have slight biases in their white balance systems under various lighting conditions. Once you get used to how a particular camera shoots, it can be very helpful to have this sort of "tweaking" adjustment available to modify the color shift.)
The C-5000 Zoom has a 12-second Self-Timer for self-portraits or those occasions when you don't want to risk camera shake by pressing the Shutter button to make the exposure. A Remote Control mode works with the accessory remote unit, letting you trip the shutter from a greater distance away. When the remote control is used to trip the shutter, there's always a 3-second delay between pressing the remote's button and when the shutter actually fires. (As I mentioned earlier, I'd really like to see an option for the remote to trip the shutter with no delay.) The Function menu option lets you capture images in Black & White or Sepia modes. The camera also offers contrast, sharpness, and saturation adjustments, all in +/- five-step increments.
Flash
The C-5000 Zoom has a fairly standard built-in flash, with five basic operating modes: Auto, Red-Eye Reduction, Fill Flash, Flash Off, and Slow Synchro modes. Flash range extends to approximately 12.5 feet (3.8 meters). The Slow Synchro mode combines a slow shutter speed with the flash to let more ambient light into the image. This results in more natural lighting behind flash-illuminated subjects. When photographing moving subjects, Slow Synchro will record some motion blur because of the longer exposure time, with the initial or final image frozen by the flash exposure. I say "initial or final," because the Slow 1 menu option fires the flash at the beginning of the exposure (producing a blur in front of the subject), while Slow 2 fires the flash at the end of the exposure (producing a blur behind the subject, where you'd generally expect to see it). There's also a Slow Red-Eye Reduction mode, for portraits.
An external flash hot shoe on top of the camera replaces the five-pin proprietary flash sync socket found on the C-4000 model, and lets you connect a more powerful external flash. The shoe works with Olympus' FL-20 and FL-50 external flash units, which can be controlled through the camera. Both the internal and external flash units can be used together or separately. Happily though, the shoe also works with ordinary "dumb" automatic flash units, so chances are that any old flash unit you have laying around will work with the C-5000. (Just check to make sure that your generic flash has an acceptably low trigger voltage, preferably 5 volts or less.)
Another nice feature of the C-5000 Zoom's internal flash system is its Flash Brightness adjustment, which allows you to change the flash brightness from +2 to -2 EV in one-third-step increments. When using the built-in flash with an external unit, you can use this feature to adjust the balance of light between the two, a very nice feature that permits subtle direct/bounce flash lighting effects.
Special Exposure Modes
Movie Mode
The C-5000's Movie mode is accessed via the Mode dial on top of the camera. Movies can be recorded in either HQ (320 x 240-pixel) or SQ (160 x 120-pixel) resolution modes. Both record at approximately 15 frames per second. Movies are recorded without sound, but one benefit of this is that the zoom lens can be used while recording. (Zoom lenses generally aren't usable when recording movies with sound because the motors that actuate the zoom lens are too loud, interfering with the audio. If you want to have the option of recording movie clips with sound, check out Olympus' C-5060 Zoom, or the C-750 UltraZoom, which offers a 10x zoom capability, albeit with the reduced resolution of a 4-megapixel CCD.) Maximum recording time per clip is limited by the C-5000 Zoom's buffer memory, but is fairly generous, as shown in the table below. Here's a copy of the recording time table from the C-5000 Zoom's manual:
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(15 frames/sec) |
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(15 frames/sec) |
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The available seconds of recording time available on the memory card
appear on the LCD monitor if it's activated, based on the quality mode
selected. (Note though, that regardless of the total amount of space
available on the memory card, individual clips cannot be longer than the times shown in the table above.) As mentioned above, you can use the zoom control while recording movies, but the motion of the zoom is somewhat slower than in still recording. Exposure Compensation, Focus Lock, Self-Timer, ISO setting, White Balance, and Function (B&W and Sepia) are also available while in Movie mode.
A very nice feature of the C-5000's movie mode is its "Index" capability, a great way of quickly seeing what's "inside" a movie file. In Movie Playback mode, selecting Index calls up a display of nine individual frames, equally spaced throughout the movie. The index is then saved as a still image file. (The C-5000 lacks the ability of the earlier C-4000, to vary the beginning and ending point of the movie index file, as well as the ability to edit a movie file by lopping off the beginning or end of it..)
Panorama Mode
The C-5000 Zoom offers a Panorama exposure mode when using an Olympus brand panorama-enabled xD-Picture Card. In this mode, the exposure and white balance for a series of shots are determined by the first exposure in the series, making them easier to stitch together in the computer later. The Panorama function is accessed in the Shooting menu through the Camera submenu. When activated, it provides light blue guide lines at the edges of the pictures to help you align successive shots, leaving enough overlap between them for the stitching software to do its job. Up to 10 shots can be taken in a panoramic series. (A note to the Olympus engineers: Why limit this function to 10 shots? On a number of occasions, I've wanted to shoot panoramas with more than 10 shots in the sequence. This may be uncommon, but I don't understand the need to limit the panorama function to a maximum of 10 shots.) Note that this function is only enabled by xD-Picture Cards with built-in panorama-related firmware found on Olympus brand memory cards. Images are saved individually and then assembled on a computer after they've been downloaded. (Another note: If you don't want to use Olympus-branded xD-Picture Cards, you can accomplish the same end by shooting in Manual exposure mode to fix the exposure parameters, and daylight or Manual white balance mode, to fix the white balance.)
Sequence Mode
Taking advantage of its relatively generous buffer memory, the C-5000 Zoom offers a Sequence mode that mimics the motor drive on a film camera, continually recording images as long as the Shutter button is held down, or until the buffer memory is full (this varies with the image quality and subject, as well as available memory card space). Available with all compression settings except uncompressed TIFF, the slowest available shutter speed in Sequence mode is 1/30 second, to prevent blurring from camera movement, or conflict between the image-acquisition time and the demands of the continuous-mode processing. One notable limitation of the Sequence mode is that the camera's internal flash cannot be used, since it can't cycle fast enough to keep up with the camera's shooting. However, if you have an external flash capable of recycling at nearly two frames per second, and you shoot in Aperture Priority mode, an external flash may work just fine. (This limitation on flash recycling in continuous mode is a common constraint, faced by all consumer-level digicams that I'm aware of.) You can also set the camera to base all exposure and focus settings on the first shot taken, or to adjust the exposure and focus with each image (which decreases capture speed).
Shooting speed and sequence length in Sequence Mode are governed by the image size/quality settings you've selected. The frame rate is approximately 1.7 frames/second in HQ mode, with a maximum number of 10 frames per sequence.
"2 in 1" Mode
Also accessed through the camera's shooting menu, "2 in 1" mode captures a split-screen image. Once the mode is enabled, the camera guides you in aligning two sequential images, which it then assembles side by side as a single image. The first image takes up the left half of the screen, and the second is on the right. Because images are divided vertically, this mode will work best with vertical ("portrait") format subjects
Noise Reduction/Low Light
This isn't really a separate shooting mode, but deserves separate mention because of the impact it has on low light performance. All digital cameras are plagued by image noise on long exposures, particularly the "hot pixel" kind caused by leakage currents on the CCD array. This noise appears as isolated bright pixels of varying colors. Like many current higher-end cameras, the C-5000 Zoom employs a "dark frame subtraction" technique to remove the hot pixels. This means that when the noise reduction option is turned on, it takes the camera twice as long to complete an exposure, since it's actually taking two shots, one of the subject, and the other with the shutter closed. The second of these will contain only the CCD noise, which the camera then subtracts from the image of the subject. The results are pretty dramatic, making even the maximum 16 second exposures from the C-5000 quite usable, and easily extending the usable light range of the camera down to the 1/16 foot-candle (0.67 lux) limit of my testing.
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