User guide

Gel Doc
3-13
DAC Settings
Note: The default DAC settings are highly recommended and should be
changed with caution.
These sliders may be used to adjust the minimum and maximum voltage
settings of your video capture board. The minimum slider defines the pixel
value that will appear as white in the image, while the maximum slider
defines the pixel value that will appear as black. The slider scale is 0–255, with
the defaults set to 60 minimum and 130 maximum.
Imaging Area
These fields are used to specify the size of your imaging area in centimeters,
which in turns determines the size of the pixels in your image (i.e.,
resolution). When you adjust one imaging area dimension, the other
dimension will change to maintain the aspect ratio of the camera lens.
Note: Your imaging area settings must be correct if you want to do 1:1 printing.
These are also important if you are comparing the size of objects (e.g.,
using the Volume Tools) between images.
Auto Exposure Threshold
When you click on Auto Expose, the exposure time is determined by the
percentage of saturated pixels you want in your image. This field allows you
to specify that percentage.
Typically, you will want less than 1 percent of the pixels in your image
saturated. Consequently, the default value for this field is 0.75 percent.
Reminder
When this checkbox is selected, the software will warn you to turn off your
transilluminator light when you exit the Gel Doc acquisition window or when
your system is “idle” for more than 5 minutes.
Note: If you are performing experiments that are longer than 5 minutes (e.g.,
chemiluminescence), this should be deselected.