Variable power optical system

1. A variable power optical system on a common optical axis for forming a final image of an object, said system having an object side and an image side and at least one intermediate real image between the object and the final image, said system comprising:

at least a first variable power optical component located between the object and an intermediate real image formed by the first variable power optical component on the image side of the first variable power optical component, the first variable power optical component being located adjacent to the intermediate real image, wherein the first variable power optical component varies power to change a magnification of the intermediate real image;

at least a second variable power optical component located between the intermediate real image and the final image, wherein the second variable power optical component varies power to change a magnification of the final image; and

a lens with a fixed positive power located between the intermediate real image and the second variable power optical component, the lens being located adjacent to the intermediate real image on the image side;

wherein at least one of the first and second variable power optical components is stationary on the optical axis and comprises at least two liquids with different refractive properties and at least one variable shape contact surface between the two liquids, with variations in the shape of the contact surface producing a change of optical power in the optical system.

2. The variable power optical system of claim 1 , wherein variation of the first and second variable power optical components provides zooming.

3. The variable power optical system of claim 2 , wherein variation of the first and second variable power optical components provides focusing.

4. The variable power optical system of claim 2 , wherein variation of the first variable power optical component provides focusing.

5. The variable power optical system of claim 2 , wherein variation of the second variable power optical component provides focusing.

6. The variable power optical system of claim 1 , wherein variation of the first and second variable power optical components provides a combination of zooming and focusing.

7. The variable power optical system of claim 1 , wherein an optical stop is located between the object and the intermediate image.

8. The variable power optical system of claim 1 , wherein an optical stop is located between the intermediate image and the final image.

9. The variable power optical system of claim 1 , wherein the first variable power optical component comprises at least one moving lens group.

10. The variable power optical system of claim 1 , wherein the second variable power optical component comprises at least one moving lens group.

11. The variable power optical system of claim 1 , further comprising at least one moving lens group located between the intermediate real image and the final image, wherein the second variable power optical component is stationary.

12. The variable power optical system of claim 1 , wherein the first variable optical component or the second variable optical component comprises a plurality of optical surfaces with at least one optical surface having an aspheric profile.

13. The variable power optical system of claim 7 wherein an iris is placed substantially at the stop location to provide a variable aperture.

14. The variable power optical system of claim 8 wherein an iris is placed substantially at the stop location to provide a variable aperture.

15. The variable power optical system of claim 1 , wherein the variable power optical system has a zoom ratio greater than about 3×.

16. The variable power optical system of claim 1 , wherein the variable power optical system has a zoom ratio between about 2.8× and about 4.4×.