Briefly answer the following questions.
(1) Is the visual sensation time longer or shorter when the intensity of light forming the image is weaker?
(2) We use a converging lens as the objective (focal length fo λ 25 cm) and a diverging lens as the eyepiece (focal length fe λ 5cm) to construct a simple Galilean telescope. What should be the distance between the lenses?
(3) Hold two illuminated pinholes at the anterior focal plane of the eyes, say, about 17 mm in front of the eyes.
Describe or draw what you see when two pinholes are separated by a distance equal to the diameter of the pupil.
What do you see when two pinholes are separated by a distance shorter than the diameter of the pupil?