Night Vision

Purpose - To demonstrate your ability to view contrastingcolors at night.

Materialsscissors ruler

constructionpaper, black, dark brown, and white cellophane tape

cardboardbox about 1x1x2 feet (30 x 30 x 60 cm) stoolabout 21/2 feet (75 cm) tall

Procedure

¦ Cut two 4-inch (10-cm) letter V’swide from the brown paper and one from the white paper.

¦ Tape the brown letter at the topof the black paper and the white letter at the bottom of the paper.

¦ Tape the black sheet of paper inthe bottom of the box.

¦ Place a stool in a dimly lit hallwayor room.

¦ Place the box on the stool so thatthe black paper is upright and shaded by the shadow of the box.

¦ Stand so that you are as close tothe box as possible, and are able to see the letters on the black paper.

¦ Observe how clearly each lettercan be read as you slowly walk backwards about 15 feet (5 m).

Results The brown letter is harder to seeat a distance than is the white letter.

Why? Contrasting colors are those colors that stand out against theirbackground. The white letter has a high contrast against the black paper, andthe brown letter has a low contrast with the black paper. In dim light or atnight you have more difficulty viewing low contrasts, such as brown on black.

Night Vision