By default, LUCID cameras are prioritized to achieve maximum frame rate. However, due to the high frame rate configuration, the exposure time will be limited to a certain number, making the resulting exposure time constrained by the frame rate.
For example, if the frame rate is 30 FPS, the maximum allowable exposure would be 1/30 = 0.0333 seconds, which is 33.3 milliseconds.
As the frame rate decreases, the exposure time will increase. In other words, to achieve a higher allowable exposure time will require a decrease in frame rate.
To do that, first set Acquisition Frame Rate Enable to true, then decrease Acquisition Frame Rate. Set Exposure Auto to OFF, and increase Exposure Time.