That presumes you have had enough time for your eyes to become dark-adapted and that no lights in the cockpit or your airfield have affected your night vision.
Otherwise you are taking off without full knowledge of the conditions and ability to see the ground. Another reason to use an instrument/visual balance for departure.
If your eyes haven't dark-adapted before take-off it can take between 20 and 30 minutes to achieve reasonable night vision and be able to accurately determine whether you can see the ground or not.
Your cones can get reasonably adapted in about 10 mins but your rods - which provide scotopic or night vision - take much longer, it can take several hours to reach full night sensitivity.
This means you need to turn your cockpit lighting down in stages during the sortie so you allow maximum adaptation for the external references. It always amazes me how dim the lights can be after an hour or so and you can still read the instruments perfectly. Even with my old eyes
