A Clear Image Appears

Surely you know magnifying glasses from your everyday life. We use them to make objects visible in a magnified form or we use them to make small print readable.

In order to get an image that is clear and as big as possible, we have to vary the distances between magnifying glass, the object and our eyes.
In both pictures you can see the magnification of the play money. Note that the image we perceive through the magnifying glass is actually an image that cannot be projected on a screen. It is not a real image because real images can be projected onto screens. Such "unreal" images are called virtual images.

The focal distance of magnifying glasses is the ideal distance between object and glass which creates the biggest possible and clear image. Accordingly the object has to be precisely in the focal point of the magnifying glass.

What do you think; is it possible to focus sunlight with a magnifying glass in order to start a fire?