Canon EOS-1DSCanon extends the EOS-1D with 11.1 megapixels, and a full-frame CMOS sensor!<<Design :(Previous) | (Next): Optics>> Page 4:ViewfinderReview First Posted: 9/24/2002 |
Viewfinder
A TTL optical viewfinder is the sole mechanism for composing images on the EOS-1Ds, as the 2.0-inch LCD monitor is purely for image review and menu navigation. (This is typical of most SLRs - The light path is either through the eyepiece or onto the CCD, with no provision for a "live" LCD viewfinder display.) Fortunately, the optical viewfinder on the EOS-1Ds offers a true 100 percent field of view, a relative rarity, even among high-end SLRs. The optical viewfinder has a glass pentaprism design, using a mirror to reflect the view from the lens, just as in a traditional film-based SLR viewfinder design. A full information overlay along the bottom of the viewfinder window reports the current exposure settings, including shutter speed, aperture, exposure compensation, and ISO, among other information. A circular black outline at the center of the viewfinder window indicates the central spot-metering area, although the 1Ds is capable of spot metering at a number of locations within the field of view. A large black elliptical outline marks the boundaries of the autofocus area. A total of 45 discrete autofocus sensors are distributed within this ellipse, and may be used singly or in combination (described in the "Optics" section of this review). Active AF points illuminate red when the Shutter button is half-pressed.
The amount of information conveyed by the EOS-1Ds' viewfinder readouts is quite impressive, all the more so because the display is actually quite uncluttered and easy to understand. The illustration below (courtesy Canon USA) shows all the internal viewfinder displays and their functions. (Readers familiar with the EOS-1v film SLR will immediately recognize the strong similarities between this display and the one used on that camera.) Because the 1Ds' sensor is larger than that on the 1D, the active frame area occupies a wider field of view in the viewfinder. Another consequence of the CCD sensor in the EOS-1D being smaller than a 35mm film frame is that the AF ellipse and spot/partial metering sensors there cover more of the image area than they do on the film-based 1v model. Because the CMOS sensor in the 1Ds almost exactly matches the 35mm frame, the metering and AF sensors cover almost exactly the same area as on the EOS-1v. On the 1Ds, the spot and "partial" metering areas cover 2.4% and 8.5% of the frame respectively, very close to the 2.3% and 8.5% on the 1v, but considerably smaller than the 3.8% and 13.5% we saw with the original 1D.
On the left side of the viewfinder eyepiece, a diopter adjustment dial corrects the viewfinder display from -3.0 to +1.0 diopter units to accommodate eyeglass wearers. The viewfinder has a moderately high eye point, meaning that the view should be reasonably clear, even with fairly thick eyeglasses. (In addition to the rather wide range of diopter adjustments available on-camera, Canon also offers dioptric correction lenses for the viewfinder ranging from -4 to +3 diopters in 10 steps. These clip on externally, and act in addition to the built-in diopter adjustment, for a total range of -7 to +4 diopters. - If you can see well enough to find the camera, you should be able to see through the viewfinder. ;-) On the right side of the viewfinder eyepiece is a small lever that opens and closes a shutter behind the eyepiece. This prevents any additional light from filtering into the camera through the viewfinder eyepiece during long exposures on a tripod. The EOS-1Ds also features a removable eyecup that fits over the viewfinder eyepiece, handy for high ambient light environments.
The 2.0-inch, TFT color LCD monitor is used only for image playback and menu viewing, and is made up of approximately 120,000 pixels. A brightness control offers five brightness levels, helpful for viewing in excessively dark or bright situations. Images can be displayed with or without the relevant image information, and the EOS-1Ds offers four- or nine-image index display modes. A very useful feature is the optional Highlight Alert, which flashes overexposed sections of the image gray/white during playback. An optional histogram display is handy for assessing overall exposure, though I've personally found the blinking highlight display much more useful for showing blown out highlights. (The problem with a histogram display is that blown highlights usually represent only a small percentage of overall image area, meaning it's hard to pick them up on the histogram readout. A blinking area on the LCD playback display is pretty hard to miss.) By activating Enlargement Mode option through the Personal Function menu, you can enlarge captured images to check on framing and detail. (Perceptive readers will note that that's a view of the LCD display from the original 1D above right - The playback screens on the 1Ds are identical.)
Active Mirror Technology
The ultra-fast EOS-1D required special "Active Mirror" technology to reduce the "settling time" when the mirror flipped up out of the way for each shot, and again, when it flipped back down. The result was very short viewfinder blackout times between exposure, as sort as 45 milliseconds. I don't know if the 1Ds uses this same technology or not, but it does seem to have a pretty short viewfinder blackout period when the shutter fires.
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