Can these lenses be used in a projector

[quakebot]

I recently destroyed my Minolta 7Hi digital camera, but the lens survived. It is a minolta gt 28-200 mm lens with a kind of focus built into it.

I also have a nice piece of glass optics from a copier machine.

Can either of these be used in an lcd projector? If so, I wll hang onto them. Maybe someday I will put them to use again.

And if I understand right, the a FL makes the image smaller. The image goes into the lens and then comes out bigger onto a wall or screen. Is this it? So you have to have a FL as bit or bigger than your LCD?

Are there different quality FLs. Or are they all about the same?


Thanks

Brad

 

[Guy Grotke]

lenses

A camera lens is only good for projection if you have an LCD the size of the film or image sensor. (ie. VERY small) The only camera lenses that really work in DIY projectors are lenses used for large-format photography. (Like 8" by 10" film plates.) Those are VERY expensive.

A copy machine lens can be great for use in a DIY projector.

The focal length is how "strong" a lens is. A long focal length lets you project a smaller image or at a longer distance to the screen. A short focal length gives you a larger image or a shorter distance to the screen.