How are digital f2.8 zoom lenses so cheap and a film one cost the earth?

[The Ever Optimist]

This is a question i have been confused by since quite some time...
How is it that a film zoom ( for an SLR for eg.) can cost the earth if it is f2.8 even if it uses the cheapest glass BUT a digital olynpus 38-380mm f2.8/3.4 lens + camera can come for under $400?
A Canon 2.8 zoom comes for around $1500 and i know that the a 50mm1.4 is 3X the cost of a 50mmf1.8 so obviously smaller aperture lenses are very expensive, the cost difference cant be explained solely on the basis that the glass used in digital P&S is cheap and the SLR lenses have expensive glass.

Does this mean that the meaning of aprture changes for digital cameras,making it easier to manufacture?

Thanks in advance
Kunal

[Sebastian]

It's all in the SIZE of the glass. Aperture is relative to sensor size. Those lenses are TINY but can still reatin f/2 or slower apertures relatively easily. Film is much larger, and requires much larger glass to get a fast aperture.

The bigger the glass the more it costs.

[straightarm]

The digital doesn't actually have a 38-380mm lens.

It's focal length ranges from 6.3 -63mm. These give a view equivalent to 38-380 on 35mm film.

The f no is basically the ratio of the lens's focal length to the aperture diameter.

As the focal length is quite small a small diameter aperture still gives a large f no.

[The Ever Optimist]

The digital doesn't actually have a 38-380mm lens.

It's focal length ranges from 6.3 -63mm. These give a view equivalent to 38-380 on 35mm film.

The f no is basically the ratio of the lens's focal length to the aperture diameter.

As the focal length is quite small a small diameter aperture still gives a large f no.

Sheesh completely forgot my fundamentals! Thanks