The light moves at 186,000 miles per second (assuming a full vaccum) and the spaceship is traveling at. .8 the speed of light, c , so the spaceship is traveling at 148,800 miles per second. So the person in the spaceship sees the light move at a speed of 37,200 miles per second since that is how much faster the light is than him. The bystander will see the light travel at 186,000 miles per second and see a spaceship following the light at 148,800 miles per second. So the bystander and the spaceship will notice the light pull away from the ship at 37,200 miles per second but the bystander will the both the light move and the spaceship move while the spaceship only sees the light move since it has no point of reference. But assuming the human eye can see a candle at 30 miles unaided i would assume that light at 3000 miles in space would be beyond the comprehendable distance so your brain would have .1 seconds to notice the light change and by that time your reaction time for a visual is .25 seconds, you would notice nothing unusual. That good 'nough for ya johnny boy?