Manual Control Options
Manual control is a primary area of modification on the Rebel XT. Users can now select metering pattern and AF mode, alter flash and exposure compensation settings, as well as utilize 9 included custom parameters to personalize the camera to the individual user. Added tonal precision is available using a white balance correction feature, alterable in 9-tonal steps. With the emphasized manual interface, the Digital Rebel XT appears far closer to the EOS-20D in terms of performance and capabilities than to its genetic descendant. Although the camera will remain grounded in its core “casual consumer” audience, look for the Rebel XT to make a far stronger appeal to enthusiasts and an impact on the prosumer market.
Focus
Auto
The Rebel XT utilizes a newly crafted high-precision 7-point AF system, designed for speed and accuracy. The employed AF system offers both manual and automatic point selection, a substantial modification from the previous Rebel. The integration of manual AF selection helps illustrate Canon’s conscious shift towards photo “enthusiasts.” Some prosumers shied away from the original Digital Rebel because of control restrictions and imposed automatic features that often compromised the the shot. For instance, AF selection on the preceding Rebel was rendered automatically. Designed to simplify control for beginner digital SLR users, the original Rebel was engineered to first determine whether the subject was stationary or in motion prior to locking focus. The perceivable hesitation and apparent lag prior to each recorded shot proved detrimental to the Rebel’s prosumer acceptance and alienated many potential consumers. The oversimplification may have contributed to the enormous success of the Nikon D70 and has been noted and corrected by Canon on the XT.
There are three focusing modes available to select from: One-Shot AF, Predictive AI Servo AF, and AI Focus AF, which automatically selects either One-Shot AF or AI Servo AF. Predictive AF enables users to focus on mobile subjects as they move through the composition.
An AF-assist beam is also included to apply added visibility for focusing in low light. The intermittent illuminator effectively functions within a working range of just over 13 ft. from center and 11.5 ft. along the perimeter of the field of view.
Manual
Manual focus is engaged by moving the mode selection switch on the lens barrel to the “MF” position. Focus is altered by rotating the rubber focus ring surrounding the lens. The included 18-55mm EF-S series II kit lens that ships with the Rebel XT has an updated groove arrangement on the focus ring. The revised layout is meant to provide added grip and support as well as improved aesthetics.
Metering
The Rebel XT employs a “max. aperture” 35-zone SPC TTL metering system. On the XT, users can manually select the metering pattern and method used to read the scene. Evaluative metering, Partial metering (at center — approx. 9% of viewfinder) and Center-weighted average metering modes are available. The metering selection is designed to mimic a traditional 35mm, making the XT a short bridge to cross for recent film converts.
The XT’s metering range runs from 1-20 EV in “traditional” conditions, defined by Canon as: 68° F / 20° C, when shooting with a 50mm, f/1.4 lens at ISO 100.
Exposure
A hefty array of exposure controls is encased within the Rebel XT, enabling users to carefully craft the exposure. Exposure settings have been spread out over five generalized Exposure Control Systems. These include a “shiftable” Program AE, Aperture-Priority, Shutter-Priority, Automatic Depth-of-Field AE and Full Auto. There are also E-TTL II Autoflash Program AE and Manual Image Control modes.
For subtle gradations or alterations to exposure, users can opt to use the exposure compensation feature. Exposure Compensation is offered up to +/-2 stops in 1/2 or 1/3-stop increments. An Auto Exposure Bracketing system is also included to provide assistance in difficult, high-contrast lighting situations when users are unsure which tone to meter for.
When shooting in a non-Basic Zone automatic mode, an AE lock feature is activated by depressing the AE lock button.
White Balance
In marketing the second generation Rebel to more photographically educated users or engaged enthusiasts, color accuracy is far more pertinent. The majority of prosumer and professional digital photographers will concede the most frustrating challenge of digital photography is attaining proper color calibration. With digital processing taking place within the camera body, users have to rely on the camera’s white balance function to accurately replicate realistic tones. To attain color precision, Canon has included a multitude of manual and automatic controls to help users adapt to virtually any lighting situation.
For more automatically inclined Digital Rebel users, the XT stocks 6 preset white balance options to supplement the full Auto setting. Among these presets are Daylight, Shade, Cloudy/Twilight/Sunset, Tungsten light, White fluorescent light, and Flash options. While this is not quite as comprehensive as the included presets on many point-and-shoot models, engaged users can utilize the customizable Manual white balance feature to orient the camera to a selected shade of “pure white.” When color difficulties still persist, a white balance correction feature has been appropriated from the professional portion of the EOS digital SLR line. The white balance correction feature is accessed through the menu setup and provides an interactive grid that users can alter in 9 steps in either the Blue-Amber or Magenta-Green directions.
ISO
The Rebel XT is slated for significantly improved low light capabilities. Along with the inclusion of a long exposure noise reduction feature, the Rebel XT offers a versatile manual sensitivity range, equivalent to ISO 100-1600. When using the auto ISO setting, the available ISO range is significantly abridged to a typical point-and-shoot selection of 100-400.
Several internal modifications have improved the Rebel XT’s low light performance and noise suppression. The pixel configuration on the sensor has been redesigned to maximize sensitivity and minimize distortion. The photodiode or light sensitive portion beneath each microlens has also been directly enhanced to reduce the signal amplification necessary to attain a detailed exposure. Additionally, the microlenses themselves have been enlarged, though the overall size of the pixels have been reduced. The increased lens area will attract more light to each individual pixel, minimizing the vacant space between microlenses and creating more sensitized surface to absorb information. This is a far more efficient and effective system of information gathering and should significantly improve the camera’s low light performance. Canon has also applied an on-chip Noise Reduction Circuit to the XT’s CMOS sensor for added noise protection.
The addition of the DIGIC II Processor also assists in reducing apparent noise or grain distortion by increasing the accuracy of data analysis. The DIGIC II can more accurately discern the boundaries between adjacent pixels and interpret whether the perceived variance in pixel values is attributed to detail in the image or noise. With these alterations applied to the 100-1600 ISO range available, XT users should have plenty of flexibility in difficult lighting.
Shutter Speed
Exposure duration on the Rebel XT is controlled by the “soft-touch” electromagnetic focal-plane shutter, alterable from 1/4000th to 30 seconds in general modes in either 1/2 or 1/3 incremental steps. The camera syncs with the flash at 1/200th of a second. For time lapse shots and long exposures, users can hold down the shutter for an extended amount of time by setting the shutter speed to “bulb.” Bulb exposures will likely be recorded using a tripod and the wired remote control.
