SPOT 4.1 Basic and Advanced Software Manual for SPOT Insight ...

Appendix AAn 80 second exposure at a gain of one turns into a 5 second exposure at gain 16. This is good in terms ofthe exposure time. Unfortunately, background noise is directly proportional to gain. It is 16 times higher ata gain of 16 is than at a gain of one.An Automated Exposure ProcessNormally, for any given image, trial and error would have to be used to determine the optimalcombinations of gain and exposure time. In order to eliminate the need for trial and error experimentation,the SPOT camera automatically determines this information by sampling light levels before each exposure.Based on the light levels and the user-determined Auto-Gain Limit, SPOT determines the optimal gainsetting and exposure time for the image. For details on using the Auto-Gain Limit feature, refer to Ch. 5 –Preparing to Take a Picture.316 User Guide to the SPOT Insight Camera