How to draw a pinhole camera?

Drawing a hole camera is very easy because it has no lenses whose focal length must be observed. It always forms sharply independently of object distance and image distance. I only depend on the diameter of the hole.

You draw your object on the left edge of the sheet. Then miss the object distance and draw the front wall with the hole. At the distance of the image width, you draw the screen. Now “Click” the object with the ruler and mark the corresponding picture point where the ruler, when it goes through the hole, meets the matte disc. In this way, you image the object point by point on the matte disc.

If you select the object width and the image width differently, you can easily calculate how the ratio of the four dimensions (object size, object distance, image size, image distance) can be mathematically described.