Service manual

G6
-Auto Exposure Bracketing (AEB)
The PowerShot G1 provides Auto Exposure Bracketing (AEB) which takes three shots bracketed automatically within the
set range. The three bracketed shots are taken with a single shutter release.
If there is a large difference between the light levels of the main subject and the background, or if a highly reflective object
is in the scene, it is often difficult to obtain a proper exposure value, making exposure compensation necessary. With this
feature, the camera automatically takes three pictures with three different exposure settings, so it is not necessary for the
user to repeatedly shoot the same subject with different exposure settings himself.
The framing of the picture also remains
virtually the same during AEB shooting.
The shots can be bracketed up to +/-2 stops at 1/3-stop increments. The bracketing sequence is normal, - compensation,
and + compensation.
If exposure compensation is also set, the bracketing range will center on the exposure compensation amount and it can be
set up to +/-2 stops at 1/3-stop increments.
Note: In using flash, AEB is not available.
-Built-in flash with five control modes
In addition to the auto flash, auto red-eye reduction, manual flash, and flash off modes, the PowerShot G1 also provides
the manual red-eye reduction mode. Previous models only had auto red-eye reduction, so the red-eye reduction light
would only emit when necessary. But with the manual red-eye reduction mode, you can emit the red-eye reduction light at
will.
-Movie recording and playback
The PowerShot G1 can record a QVGA (320
X240 pixels) video clip (with audio) at 15 frames per second up to approxi-
mately 30 sec. The movie can be played back on the built-in LCD monitor or on a TV monitor. The movie is ideal for
studying the subject’s movement or to record a sequence. The movie is compressed with Motion JPEG and saved as an
AVI file. Motion JPEG compresses each frame of the video in JPEG format.
Note:
- If the unoccupied capacity of the CF card is less than the capacity the buffer memory, movie recording is restricted to
the capacity of the CF card.
- When the buffer memory becomes full while a movie is being recorded, the data is written to the CompactFlash card. During the
writing to the CF card, the movie recording cannot proceed further.
- The focal length, exposure setting, white balance, and lens zoom position set for the first movie frame are used for the rest of the
video clip.
-Slow shutter speed mode up to 8 sec. (With noise reduction)
In the shutter speed-priority AE and manual modes, a slow shutter speed up to 8 sec. long is possible. It is useful in low
light when flash cannot be used.
Normally with a CCD, long exposures tend to create noticeable noise. The PowerShot G1 therefore executes noise reduc-
tion for shutter speeds 1.3 sec. or longer.
The method can be described as follows: After the user takes a picture, the camera itself takes a picture, with the aperture
closed, for exactly the same length of time. This results in only noise data, and the camera subtracts the amount of that
noise data from the user’s image, producing a noiseless image.
Note: When noise reduction is executed, some extra time is required while the black data is taken.
Example 2: Exposure compensation of 2/3 stop
(For +2/3-stop exposure compensation)
-4/3 -3/3 -2/3 -1/3 0 1/3 2/3 3/3 4/3 (EV)
Fig. 2-2 AEB.
1st shot
2nd shot
3rd shot
-4/3 -3/3 -2/3 -1/3 0 1/3 2/3 3/3 4/3 (EV)
Example 1: Exposure compensation of 1 stop
(For a standard exposure)
1st shot
2nd shot
3rd shot