Canon EOS 40D Instruction Manual page 100

Using the Built-in Flash
Effective Range of Built-in Flash
EF-S18-55mm f/3.5-5.6 IS
ISO
Wide Angle:
Speed
18mm
100 1 - 3.7 / 3.3 - 12.1 1 - 2.3 / 3.3 - 7.5 1 - 3.3 / 3.3 - 10.8 1 - 2.3 / 3.3 - 7.5
200 1 - 5.3 / 3.3 - 17.4 1 - 3.3 / 3.3 - 10.8 1 - 4.6 / 3.3 - 15.1 1 - 3.3 / 3.3 - 10.8
400 1 - 7.4 / 3.3 - 24.3 1 - 4.6 / 3.3 - 15.1 1 - 6.5 / 3.3 - 21.3 1 - 4.6 / 3.3 - 15.1
800 1 - 10.5 / 3.3 - 34.4 1 - 6.6 / 3.3 - 21.7 1 - 9.2 / 3.3 - 30.2 1 - 6.6 / 3.3 - 21.7
1600 1 - 14.9 / 3.3 - 48.9 1 - 9.3 / 3.3 - 30.5 1 - 13.0 / 3.3 - 42.7 1 - 9.3 / 3.3 - 30.5
H: 3200 1 - 21.0 / 3.3 - 68.9 1 - 13.1 / 3.3 - 43.0 1 - 18.4 / 3.3 - 60.4 1 - 13.1 / 3.3 - 43.0
Detach the lens hood and keep at least 1 meter/3.3 feet away from the subject. If the
lens has a hood attached or you are too close to the subject, the bottom of the picture
might look dark due to the obstructed flash. If you use a telephoto lens or a fast lens
and the flash is still partially obstructed, use an EX-series Speedlite (sold separately).
3 Using Red-eye Reduction
Using the red-eye reduction lamp before taking a flash picture can
reduce red eye. Red-eye reduction will work in any shooting mode
except <3> <7> <5>.
The red-eye reduction feature is most effective when the subject looks at the red-
eye reduction lamp, when the room is well lit, or when you go closer to the subject.
When you press the shutter button halfway, the viewfinder display on the bottom
will gradually turn off. For best results, take the picture after this display turns off.
The effectiveness of red-eye reduction varies from subject to subject.
100
EF-S17-85mm f/4-5.6 IS USM
Telephoto: Wide Angle:
55mm
Under the [1] tab, select [Red-eye
On/Off] and press <0>. Set it to
[On], then press <0>.
In flash photography, when you press
the shutter button halfway, the red-
eye reduction lamp will light. Then
when you press the shutter button
completely, the picture will be taken.
[Approx. meters/feet]
Telephoto:
17mm 85mm