This post is for Standard Grade and Intermediate 2.

Here we consider an object closer than one focal length.  You will see that it is not possible to obtain a real image when the object is this close to the lens.  On a ray diagram, a real image is one that is found on the other side of the lens from the object.

Real images can always be displayed on a screen – a projector in the cinema or classroom produces a real image.  If you are doing an experiment, you can check to see if an image is real using a piece of paper.  Move your sheet of paper closer to and further from the lens – if you can’t get an image to form on the paper then the image must be virtual.  When we look at an object up close through a magnifying glass, we see a virtual image.

ray diagram for objects closer than 1f from mr mackenzie on Vimeo.

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