Mammoth Memory

Convex lens – object at `F`

An object at `F` is an object at one principal focal length away from the convex lens.


We use the two most important rules of ray diagrams

  1. From the object, pass a parallel line through the principal focal point.
  2. From the object, pass a ray line through the centre of the convex lens.


Ray diagram showing an Object at F will not produce an image

The refracted rays travel parallel with each other. You cannot see an image by looking or using a sheet of paper.

At `F`, no image


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