Bring it into focus

Converging lens explorer

Move an object around a converging lens to compare real, virtual, upright, and inverted images.

Converging lens explorerTRY IT YOURSELF
FFObjectImage
Image distance16.67 cm
Magnification-0.67
Image typeReal
OrientationInverted
Teal + amber · follow the changing valuesIdealized physics model

What if you changed…

Try a starting point

YOUR NEXT AHA

Move the object inside the focal length. How does the image change?

See the calculation

1/f = 1/dₒ + 1/dᵢ · M = −dᵢ/dₒ
  1. 1/dᵢ = 1/10 − 1/25 = 0.06 cm⁻¹.
  2. Image distance = 16.67 cm. Magnification = −dᵢ/dₒ = -0.67.
  3. Image height = M × hₒ = -2 cm.

What this model assumes

Ideal thin converging lens and paraxial rays. A positive object distance represents a real object; negative image distance represents a virtual image.

Keep an eye on this

At the focal point, outgoing rays are parallel and there is no finite image position. Very large images may extend outside the schematic.

Understand the physics ↗
A little question. A clearer picture.

Converging lens explorer: common questions

Wondering about the why? Start here.

What is a virtual image?

It appears where backward extensions of light rays meet. The rays do not actually converge there, so that image cannot be projected directly onto a screen.

What does negative magnification mean?

The image is inverted relative to the object. Its absolute value gives the ratio of image height to object height.