Exposure The EOS-1Ds employs the same metering system as the EOS-1d and EOS-1v, and the partial and spot-metering areas are the same as with the EOS-1v film camera, due to the full-frame-size image sensor. We especially liked the excellent 21-zone evaluative metering, which is linked to the 45 focusing points for amazing exposure accuracy. The camera also provides partial metering, which emphasizes the central 8.5% of the image area (vs. 13.5% in the EOS-1d), and center-weighted average metering. There's also 2.4% (vs. 3.8% in the EOS-1d) spot metering, which can be linked to one of 11 or 9 AF points via Custom Function 13. Multi-spot metering lets you take up to eight spot readings, viewing the relative exposure levels on the viewfinder's exposure-level scale. The EOS-1Ds provides all the EOS exposure modes: shiftable program AE (to shift it, just rotate the Main Dial until the desired shutter speed or aperture is displayed), shutter- and aperture-priority AE, depth-of-field AE and metered manual. Using Custom Function 16, you can activate safety shift in shutter- and aperture-priority AE, so that the camera will automatically change the user-selected shutter speed or aperture if necessary to prevent over- or underexposure. With depth-of-field AE, you autofocus on the first subject you want in focus, then on the second. The camera will calculate and set (if possible with the light level, lens and film-speed in use) the aperture and focus point needed to get both subjects within the depth-of-field limits. For further control, you can lock-in an exposure by pressing the * button, set ±3 stops of exposure compensation (in 1/3- or 1/2-stop increments), and engage automatic exposure bracketing (with bracketing via shutter speed in aperture-priority and depth modes, via aperture in shutter-priority AE, both in program AE mode, or either in manual mode). You can also set autobracketing via the ISO speed, to maintain the same shutter speed and aperture. Flash The EOS-1Ds doesn't have a built-in flash unit, because few pros desire that feature. But it offers some great flash capabilities via the dedicated hot-shoe for the Canon Speedlite 550EX (and other Canon Speedlites, but the 550EX is the best match for this camera). There's also a threaded polarity-independent PC terminal for studio flash systems. Attach the 550EX directly to the hot-shoe (or use it off-camera wirelessly), and you get a number of terrific features. E-TTL autoflash uses preflash evaluative metering keyed to the focused subject to provide optimum exposures for flash and ambient light. High-Speed Sync (FP Flash) lets you shoot flash photos at all shutter speeds—up to the camera's maximum 1/8000 (at close range). Flash Exposure Lock (FE Lock) is the flash equivalent of AE lock. Flash exposure compensation lets you adjust the flash output ±3 stops in 1/3-stop increments. Flash Exposure Bracketing (FEB) shoots three frames in which the flash output is varied while the ambient (background) exposure remains constant. Modeling Flash mode lets you preview the effects of the flash lighting, courtesy of a series of pre-flashes. Stroboscopic Flash mode causes the flash unit to emit a rapid series of bursts, allowing you to capture strobe-effect shots. And Wireless Multi-Speedlite E-TTL flash lets you move one or more 550EX or 420EX units off-camera for tremendous lighting versatility, with full E-TTL exposure control. The camera provides second-curtain sync with the 550EX, and even with Canon EX flash units that don't offer it, second-curtain sync is available via Custom Function 15. Digital Features The EOS-1Ds produces images with a maximum resolution of 4064x2704 pixels, or 10.99 megapixels. This means the images can be published with film quality at sizes up to 13.5x9 inches in high-end publications that use a 300-line screen, or up to 27x18 inches in newspapers that use a 150-line screen. They'll also yield great inkjet prints up to at least 27x18 inches. There are four image-recording modes: RAW, which "losslessly" compresses images to 11.4 MB each (uncompressed 11-megapixel TIFF files would require more than 30 MB each on your storage media); two levels of JPEG compression at full resolution (resulting in file sizes of 4.1 or 1.7 MB); and a reduced-size (2032x1352-pixel, or 2.74-megapixel) JPEG compressed file (1.4 MB). You can also elect to record both RAW and JPEG files at the same time (thus giving you an easily transmitted JPEG file plus a high-quality RAW file for archiving). You can add audio notes to any image via the built-in microphone. Images can be stored on Type I and Type II CompactFlash cards, or Microdrives. Currently, both CF cards and Microdrives are available in capacities up to 1GB, which will hold around 87 RAW images (or around 240 4.1MB Large/Fine 11-megapixel images). You can download images via a card reader or FireWire/IEEE 1394 interface. ISO speeds are adjustable from 100-1250 (down to ISO 50 via Custom Function 03) for any shot, so you can make each shot at the most appropriate ISO—something you can't do with roll film. As with film, it's best to use the lowest ISO rating that will let you get your shot, because higher ISOs result in lower image quality (and larger image files that take up more space on your storage media). As with the EOS-1d, you can choose your "color space"—four variations of standard sRGB, plus the popular Adobe RGB 1998, which provides a wider range of colors. There are also 10 white-balance settings, including one you can customize. However, as with the EOS-1d, we got good results—even under fluorescent lighting—using the default Auto setting. The camera even provides white balance auto bracketing, which shoots three consecutive images, each at a different white-balance setting. The EOS-1Ds's 2.0-inch TFT color LCD monitor doesn't serve as an electronic viewfinder, as monitors do on consumer digicams (the camera's SLR finder—which shows 100% of the actual image area—serves that purpose admirably, just as it does on EOS film cameras). Rather, it is used for setting digital functions (you can set shooting functions without it) and for reviewing images after they've been taken. A nice touch: The LCD monitor is positioned where you won't put noseprints on it, whether you use your right eye or left eye at the viewfinder.