Pinhole

1) All the light spots on the negative were darker on the postie & also the positive was more detailed.
2) Dictionary;; Negative - noting an image in which the brightness values of the subject are reproduced so that the lightest areas are shown as the darkest.
My definition is basically that it captures the luminance or light of the picture. 
3) If the light in the picture hits 0 degrees, which means it's head on, it won't bend but if it is being hit at with an angle of 90 degrees or more it will bend the opposite direction.