Canon Canon EOS Rebel S Instruction Manual - Page 51

IV. OTHER INFORMATION Film Speed (ISO Number) The film speed is a value which indicates the level of the film's sensitivity to light, as set by the ISO (International Standardization Organization). The camera displays the film speed on the display panel in a range from 6-6400. The higher the ISO number, the higher the film's sensitivity to light. While film with a higher sensitivity is more suitable for lowlight situations. The higher the film speed film, the lower the level of light required for photography, and so pictures can even be taken in dark places. Depth-of-field Depth-of-field is the area that is in focus in front of and behind the subject which is also in focus. When the aperture is smaller (i.e. when the aperture value is larger), the area in focus is more extensive, and this is called a deep depth-of-field. Conversely, when the aperture is larger (i.e. when the aperture value is smaller), the depth-of-field becomes shallower. Depth-of-field has the following properties. (1) The larger the aperture value, the deeper the depth-of-field. ...increase the aperture value to create a feeling of depth. (2) With the same aperture value, a greater depth-of-field will be obtained using a lens with a shorter focal length. ...using a wide-angle lens or the wide angle setting on your zoom lens will create a feeling of expansiveness and depth. (3) With the same aperture value, a greater depth-of-field can be achieved the further away the main subject in focus is. (4) If the subject in focus is in the center field, the depth-of-field will be shallower. In-focus range 0 -- Point of focus 51