III. FEATURE DISCUSSION 10
New High-Precision
9-Point AF System
I
f you use the Dust Delete Data feature and do not want to change the data of the dust
c
oordinates, you can disable the default self-cleaning operation so it does not operate
w
hen the power is turned on or off. If you want to stop the Dust Delete Data from being
a
ppended to the images, the Dust Delete Data must be erased with the [Clear all camera
s
ettings] menu item.
D
PP Ver. 2.1 had the copy stamp tool for manually selecting and erasing round dust
spots. This feature has been improved with the DPP Ver. 2.2 which can use the Dust
Delete Data to erase the dust spots automatically.
When an image contains Dust Delete Data, the automatic dust spot erasing process acti-
vates by starting the copy stamp tool and pressing the [Apply Dust Delete Data] button.
With DPP Ver. 2.2, the dust spots at the locations specified by the Dust Delete Data are
detected and erased if doing so is
deemed effective. This modest bit of arti-
ficial intelligence will be appreciated by
anyone who has done a little spotting or
retouching because certain things (and
it’s often difficult to figure out just which
ones) look worse after they’ve been
repaired and are better off left alone.
The Digital Rebel XTi has the same 9-point AF sensor and
AF unit as the EOS 30D, including the sophisticated dual-
precision cross-type sensor in the center AF position.
This represents a very substantial upgrade from the
Digital Rebel XT. The XTi is the first entry-level EOS Digital
camera to have an enhanced precision cross-type, center
AF point compatible with f/2.8, a feature unique in its
class. The XTi has some significant AF performance
improvements over the Digital Rebel XT. For example, the
XTi h
as the same wide-area focusing as the EOS 30D.
With an f/2.8 or brighter lens, the center AF point detects
focus with the f/2.8 light flux. The base line of the center
AF point's vertical-line sensitive sensor is twice as long
as that of an AF point compatible with f/5.6. This makes
focusing detection more precise.
Additionally, the center AF point has a vertical-line sensitive sensor compatible with
f/5.6. Therefore, cross-type focusing is possible with any EF lens. The center AF point's
horizontal-line sensitive sensor for f/5.6 has a two-line, zigzag pattern. This redundancy
of focusing methods makes focus detection more consistent. As in the case of the EOS
30D, fine-tuning has been incorporated to improve the AF precision. Focusing perform-
ance under low light has been improved by 1 stop and is now possible from EV -0.5 to
D
igital Photo ProfessionalVer 2.2
