# Forming a ray diagram

To set up a ray diagram, you need to start by using a Near or Far object marker. All parts in your ray diagram will be associated with the optical axis from the object marker.

You can place both lenses and mirrors on the axis to form a ray diagram. Other optical parts will be opaque and cannot be used.

Ray diagram simulation takes place as soon as you place a lens or mirror on the axis, and rays of light appear from the object. These rays, along with the optical axis, will be transformed depending on the nature of the lens or mirror you use.

## See also:

- Forming an image
- Lens
- Mirror
- Object marker