3.6.2Stoichiometry

Real and Virtual Images — Cambridge IGCSE Chemistry 0620 Revision Notes & Topical Questions

5 min read 4 parts Lesson 13 of 28 Unit quiz

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Part 1 of 4Image Types

Whether an image is real or virtual depends on whether light actually converges at the image position.

Real image

Formed where light rays actually converge, so it can be projected onto a screen, and it is always inverted.

Virtual image

Formed where rays only appear to meet when traced backwards, so it cannot be projected and is always upright.

Projector example

A projector lens forms a real image on a screen, which is why the picture can be seen by a whole audience.

Magnifying glass example

A magnifying glass held close to text forms a virtual, upright and magnified image that can only be seen through the lens.

Moving the object changes the image type, size and orientation.

With the object beyond 2f, a real, inverted and diminished image forms between f and 2f on the far side of the lens.

With the object exactly at 2f, a real, inverted image of the same size forms at 2f on the far side of the lens.

With the object between f and 2f, a real, inverted and magnified image forms beyond 2f on the far side of the lens.

With the object closer than f, a virtual, upright and magnified image forms on the same side of the lens as the object.

Object position	Image type	Orientation	Size
Beyond 2f	Real	Inverted	Diminished
At 2f	Real	Inverted	Same size
Between f and 2f	Real	Inverted	Magnified
Closer than f	Virtual	Upright	Magnified

Diverging Lens Images

Always virtual

A concave lens forms only virtual images, however far away the object is placed from the lens.

Always upright

The virtual image from a concave lens is the same way up as the object, so it is never inverted.

Always diminished

The image from a concave lens is smaller than the object, so it appears to be shrunk.

Ray tracing

Draw a ray through the centre and a ray parallel to the axis that appears to come from the focus, then trace both backwards.

Real image An image formed where light rays actually meet, which can be projected onto a screen.
Virtual image An image formed where light rays only appear to meet, which cannot be projected onto a screen.
Inverted Upside down compared with the object.
Upright The same way up as the object.
Ray diagram A scale drawing that uses principal rays to locate and describe an image.

Saying a virtual image can be projected onto a screen; a virtual image cannot be captured on a screen.
Describing any image seen through a lens as real; real images need light rays to actually converge.
Ignoring the object position relative to the focal length when deciding whether the image is real or virtual.
Drawing a virtual image on the far side of the lens rather than on the same side as the object.

Last updated: 28 October 2026