User`s guide

INDEX
61
image. It is available on scanners that are able to increase the CCD exposure time.
A first pass is performed as usual with the normal RGB exposure. This will be an
appropriate exposure for the image as a whole. Then a second pass is performed with
a longer exposure, which can reveal additional detail in dark areas not captured in the
first pass. VueScan then merges the results of the two by choosing from either the first
or second exposure pass.
Advanced Option: This option is displayed when the scanner can control the CCD
exposure time.
Input | Lock exposure
Set this option to lock the CCD exposure values to auto-exposure values computed for
the most recent preview or scan, or as adjusted manually with the Input | RGB exposure
(p. 61) option.
This option can save time when scanning a batch of images with similar characteristics,
e.g. a roll of film.
If you turn on this option and also clear Crop | Auto offset (p. 65)and Crop | Auto rotate
(p. 66), then the Scan button (p. 47) will not perform a preview scan. This can save
time when batch scanning.
Note that locking the CCD exposure values doesn't lock the brightness of the final
images - it only locks the brightness of the raw scan files. To lock the brightness of the
final images, use the Input | Lock image color (p. 62) option.
See the "Advanced workflow suggestions" section of this User's Guide for more
information.
Advanced Option: This option is displayed when the scanner can control the CCD
exposure time.
Input | RGB/Infrared exposure
On scanners that are able to vary the CCD exposure time, this option lets you multiply
the exposure time by a user-specified value. This can be useful when scanning very
dark slides with bright highlights and you want to get more detail from the dark areas.
There's seldom any reason to increase these values from those computed by the auto
exposure.
If the CCD is over-exposed when scanning color negative film, then the film base color
gets messed up and the dark areas of the image (the bright parts of the negative) will
lose detail.
Note that these exposure values do not directly control the brightness of the final image
- this is controlled by options in the Color tab. These exposure values control the
brightness of the raw scan file only.
Advanced Option: This option is displayed when the scanner can control the CCD