Specifications

AUTOSTAR CCD PHOTOMETRY 9
Figure 2-7. Envisage Screen With CCD Camera Operating.
2. Determine exposure time(s) that allows reasonable maximum
count values for the stars of interest, but less than 65,535 counts.
(See Fig. 2-7.) This includes both the program and comparison
stars, and in each filter. Do not worry if some of the other field star
images are saturated. As long as they are not of interest (in the
photometry program) and do not overlap the stars that are of
interest, it will not matter. Do not pay any attention to the
histogram or other items in the Stats area.
Remember, different filters can have different exposure times.
Make sure the Gain and Offset are at the default settings of 100
and 50, respectively. At these settings, a count of less than 65,535
will be in the linear region of the CCD.
3. Set the exposure time. Figure 2-8 shows a screen shot of the
area where you can set the exposures.