Canon PowerShot G1Canon combines dead-easy auto shooting, full manual control, and excellent image quality in a killer3 megapixel!<<Optics :(Previous) | (Next): Shutter Lag & Cycle Time Tests>> Page 6:Exposure & FlashReview First Posted: 10/28/2000 |
Exposure
The G1 offers excellent exposure control, with Automatic, Program AE (P), Shutter Speed Priority AE (Tv), Aperture Priority AE (Av), Manual (M) exposure modes, and a handful of special settings for specific shooting situations. Under the Automatic exposure mode, the camera controls both shutter speed and aperture settings, giving you control of digital telephoto, flash, compression, and image resolution or quality. The Program AE mode also takes control of the shutter speed and aperture settings, but allows you to adjust all other exposure controls, including exposure compensation, flash, flash exposure compensation, spot metering, ISO adjustment, AE lock, auto exposure bracketing, white balance, contrast, sharpness, and color saturation.
Shutter Priority mode puts you in control of the shutter speed setting (from 1/1,000 to 8 seconds), while the camera chooses a corresponding lens aperture. As with the Program AE mode, you maintain control over all other exposure options. Aperture Priority works along similar lines, except that you control the aperture (f/2.0 to f/8.0) and the camera chooses the best shutter speed. Both the shutter speed and aperture values are displayed on the LCD monitor. If the camera doesn�t agree with the exposure settings you�ve selected, the LCD indicators will turn red, letting you know that either the aperture or shutter speed needs to be corrected.
Several preset exposure modes are also available for shooting under special conditions. Pan Focus mode sets the camera lens at maximum wide angle, so your subjects will be in focus close-up and far away (25.6 inches/65cm to Infinity). Portrait mode uses a large aperture setting to reduce the depth of field, resulting in blurred backgrounds and strong focal emphasis on the primary subject. Landscape mode uses a small aperture to keep both the foreground and background in sharp focus. A slow shutter speed is also common in Landscape mode, so it's recommended that you use a tripod.
Night Scene mode uses a slow shutter speed to capture the color and detail of an evening setting, along with a flash exposure to illuminate the primary subject in the foreground. When slow shutter speed and flash are used together, the overall scene is more evenly exposed. This mode can also be combined with the red-eye reduction flash for portraits. A tripod is also recommended when working in Night Scene mode, and portrait subjects should be warned to stay still after the flash, until the shutter is closed. Black and White mode is self-explanatory, as it simply captures images in black-and-white monotone tones.
A quick-review mode allows you to confirm the recorded image. To access the Review mode, you can either continue to hold down the shutter button after it fires, or press the Set button after capturing the image. The image will be displayed in the LCD monitor for two seconds (or 10 seconds, if the option is changed in the Record menu). You can immediately erase the image by pressing the "*" button, which pulls up a small erase menu on the bottom of the monitor. Press the right arrow button to highlight "OK" and press the Set button again to complete the erasure.
Exposure compensation can be adjusted from �2 to +2 EV (exposure values), in one-third-step increments. The camera�s metering system offers two operating modes: Center-Weighted Averaging and Spot Metering. Center-weighted averaging is based on an averaged reading of the overall scene, plus a reading from the center of the viewfinder or LCD monitor. Spot metering reads only the center of the image�that area that falls within the crosshairs of the viewfinder or within the small square that pops up on the LCD monitor when you press the Spot Meter button. Spot metering is useful when you're shooting under backlit conditions. In these situations, you can use the spot meter to obtain a reading of the subject you want properly exposed, then lock the exposure with the AE Lock function, (activated by pressing the "*" button on the back panel), and recompose your shot for the final exposure. (Note: depressing any other button on the camera will disengage the spot metering function.)
The G1 offers seven white balance modes, including Auto, Daylight, Cloudy, Tungsten, Fluorescent, Flash, and Custom. The Custom mode allows you to manually set the white balance by holding a white card in front of the camera and pressing the "*" button to set the value. ISO film speed equivalents are set in the Record menu, with a choice of Auto, 50, 100, 200, or 400 ISO values. The higher the ISO setting, the more you can extend the camera's exposure range in low-light situations. Just keep in mind that higher ISO values have slightly lower quality levels. Other manual exposure adjustments in the Record menu include: Image sharpness, Contrast, and Saturation. These give you a little more creative control over your images.
FlashThe G1's built-in flash operates in one of five modes: Auto, Red-Eye Reduction (Auto), Red-Eye Reduction (Normal), Flash On, and Flash Off. The Auto mode enables the camera to determine when flash is necessary, based on existing exposure conditions. Flash On means that the flash fires with every exposure, regardless of lighting conditions, and Flash Off completely disables the flash. The two red-eye reduction modes fire a small pre-flash before the full flash, to reduce the dreaded red-eye effect in portraits. The difference between the two red-eye modes is that the auto mode puts the camera in charge of when to use the flash, while the normal mode fires the flash with every exposure. All flash modes are accessed by pressing the Flash/Index button to the left of the optical viewfinder.
The amount of flash power can be adjusted from -2 to +2 EV in one-third-step increments by the using the four-function exposure compensation button on the camera's back panel. (Depressing the button four times cycles to the flash compensation adjustment.) You can also lock the flash exposure (FE) lock for a specific area of your subject, just as you would with a normal exposure. Simply center the portion of the subject you want to have metered and press the "*" button to lock the flash exposure. The flash will fire a pre-flash to lock the exposure reading, then you can recompose your image and make the exposure with the FE lock in place. (Note: Pressing any other button after the "*" button will cancel the flash exposure lock.)
Canon rates the G1's flash effectiveness from 2.3 to 14.8 feet (70cm to 4.5m), which is right in line with our test results. Though the flash was reasonably effective all the way to 14 feet, we noticed a very slight dip in brightness between 10 and 11 feet.
In addition to its built-in flash, the G1 features a hot
shoe for mounting more powerful external flash units. Canon recommends using its
own Speedlight 220EX, 380EX, 420EX, or 550EX models, but other manufacturers'
models should work as well. The instruction manual notes that when using another
manufacturer's flash unit with the G1, the maximum shutter speed for flash
synchronization is 1/125 second. (The onboard flash syncs to a maximum shutter
speed of 1/250 second.)Auto Exposure Bracketing
The Auto Exposure Bracketing (AEB) mode is the third function controlled by the exposure compensation button on the G1's back panel. It automatically captures a series of three images, each at a different exposure setting. You can manually set the exposure variables in one-third-step increments, covering a range of -2 to +2 EV, by depressing the exposure compensation button three times to activate the mode and using the arrow buttons to choose the amount of time between photos. Depress the Set button, then fully depress the shutter button to start the series. The camera makes all three exposures with just one press of the shutter button. This function cannot be used with flash photography. If the flash fires, only one image will be recorded.
Continuous Shooting
Controlled by the Continuous/Self-Timer/Wireless Remote button on top of the camera, the G1's Continuous shooting mode captures multiple consecutive pictures at up to 1.7 frames per second (fps). This frame-capture rate may vary, depending on image quality, functions in use, and the amount of internal memory available (1.7 fps is based on a "Large" image quality setting, "Fine" JPEG compression, and the LCD monitor and flash turned off). The G1 will continue to capture images as long as the shutter button is depressed, or until the camera's internal memory runs out.
Movie Mode
The G1 also offers a Movie mode, which is accessed by turning the Mode dial on top of the camera to the miniature movie camera symbol (a camera will appear in the upper left corner of the LCD display). The AVI/Motion JPEG files are recorded at a fixed resolution of 320 x 240 pixels, at approximately 15 frames per second. Recordings can last up to 30 seconds, depending on the amount of memory available on the CompactFlash card. To begin recording, you simply press the shutter button all the way down and hold it there until the red circle in the upper right corner of the LCD disappears. The flashing green LED light next to the eye-level viewfinder indicates that the camera is storing the movie. When finished, you can view the recording by switching the camera's Main dial to the blue Replay symbol, scrolling to the last frame of the movie with the arrow buttons, and depressing the Set button. The camera will play back both moving images and sound. (Note that the recording options are largely preset in Movie mode: Image resolution, JPEG encoding, Exposure compensation, White balance, and Manual focus are the only adjustable functions.)
Stitch-Assist Mode
The Stitch-Assist mode records a series of overlapping images to create horizontal or vertical panoramas, and 2 x 2-frame rectangular composites. A framing guideline for each format appears in the LCD monitor to help line up successive shots. For the panoramas, you can take as many images in a series as you want, enabling you to record a full 360-degree circle of the surrounding scenery. The 2 x 2 mode uses a series of only four images, starting from the top left corner and moving in a clockwise direction, to create a complete composite. You can then use Canon's PhotoStitch program to seamlessly combine the images in your computer.
Self-Timer Mode
The self-timer button on top of the camera also controls the continuous shooting and remote operating modes. When set to the Self-Timer/Wireless mode, the camera displays the standard self-timer icon (a clock counting down) in the LCD display, and the self-timer icon with a remote (radar) symbol in the LED panel on top of the camera. When in Self-Timer mode, depressing the shutter button activates a 12-second countdown, during which a bright blue lamp on the camera's front panel blinks, gaining speed in the last two seconds. If the camera's Beep function is turned on in the Set-up menu, you will also hear the beep counting down. While in Self-Timer mode, you can also trigger a two-second countdown by pressing the shutter button on the remote control.
Remote Sensor/Transmitter
The G1's wireless remote control allows you to trigger a two-second self-timer countdown from as far as away as 16.4 feet (5 meters) in front of the camera. It can also be used to adjust the optical zoom lens with its two Zoom buttons, and activate the LCD monitor with its Display button. By rotating the LCD monitor so that it faces you (or the subject), you can use the Zoom buttons to compose the image and the Display button to scroll through the G1's LCD information screen to check exposure settings. In Replay mode, the remote control can be used to scroll through stored images, scroll around areas within a magnified image, view an index of up to nine captures, and replay movie images.
Reader Comments! --> Visit our discussion forum for the Canon PowerShot G1!
Follow Imaging Resource: