The document provides instructions for an exercise using three Nikon DSLR cameras - the D-60, D-80, and D-90. Trainees are asked to take 20 total photos with each camera while varying the exposure through adjustments to aperture, shutter speed, and ISO. Focus and exposure settings should remain in manual mode. Notes should be taken on image numbers and settings for each photo taken with the three cameras. Links are provided for camera-specific settings on lens and display operation.