Canon XS Viewfinder

The Canon XS features a digital SLR design, so the optical viewfinder offers a true, through-the-lens (TTL) display. A dioptric adjustment dial accommodates eyeglass wearers, letting them adjust the viewfinder optics between -3.0 to +1 diopters. Coverage is rated the same as the XSi model at 95%, but magnification is lower, at 0.81x for a 50mm lens and -1 diopter, versus the XSi's 0.87x magnification. The viewfinder eyepiece has an eyepoint of approximately 21mm from the eyepiece lens center, a little higher than the XSi's 19mm eyepoint.

Like the Canon XTi, the XS viewfinder uses a pentamirror design. The advantage of a pentamirror is that it is lighter and less expensive; however, an all-glass pentaprism design delivers more light to the viewfinder eyepiece, thanks to its more efficient internal reflection. As a result, the Canon XS's viewfinder image is not as bright as the EOS 50D, which uses a true pentaprism.

The illustration below (courtesy Canon USA) shows all the elements in the Canon XS's viewfinder. The extensive information available appears beneath the image area in a small strip, and reports all of the major camera settings, such as shutter speed, aperture, flash mode, EV compensation, etc. The information display is identical to the XSi's, with the exception of the number of focus points (7 vs 9), and the absence of a spot metering circle. (The XS does not offer spot metering mode.) Compared to the XTi, the XS's viewfinder info adds ISO speed (sensitivity), a welcome addition that is even more useful now that there is a dedicated ISO button, and a Black & White mode indicator.

Viewfinder Test Results

Accuracy
Good accuracy from the optical viewfinder, excellent accuracy from the LCD in Live View mode.

18mm, Optical	55mm, Optical
18mm, LCD Live View	55mm, LCD Live View

The Canon XS's optical viewfinder proved quite accurate, showing about 98% coverage at wide-angle, and about 95% coverage at telephoto zoom settings. This is about average coverage for a consumer digital SLR. Live View mode using the LCD was more accurate, at about 102% coverage at wide angle, and 99% at telephoto. (Taking the geometric distortion from the kit lens into account, the coverage seems to match Canon's spec of 95% optical, and 100% LCD.)