Click and drag the candle to see the image size, orientation and location of the candle's image.

When doing a light ray diagram there are generally two light rays.

  1. The green light ray goes from the top of the candle parallel to the principle axis to the mirror, then it reflects and goes through the focal point on the same side.
  2. The red light ray goes from the top of the candle through the focal point on the same side of the mirror, when it intersects the mirror it then it reflects parallel to the principle axis.
Where the two light rays cross marks the location of the image. If the image is on the same side of the mirror than the object (candle) than it is a real image because you can put a screen there and get an object.

If the image is on the opposite side of the mirror as the object than it is a virtual image because you can not put a screen there because the image is behind the mirror. This is indicated by the dotted light ray lines.

Remember images on the left of the mirror are virtual images.