Fm-assets, Pty Ltd

James Albert Frazier

J Brian Caldwell

Optical lens attachments and cameras are disclosed. The attachment comprises a coupling mechanism for mating engagement with at least one of a camera and an optical lens. A barrel is coupled at one end to the coupling mechanism. A negative lens unit is coupled to the other end of elongated barrel. A diopter lens is disposed between the barrel and the coupling mechanism. The coupling mechanism, the diopter lens, and the barrel are aligned with an optical axis. Also disclosed is a double swivel optical system, comprising a negative lens unit, a mirror oriented at an angle to the optical axis of the negative lens unit, a roof prism for rotating incident light rays by 90 degrees and inverting an image, a rotation mechanism permitting rotation of the negative lens unit about a vertical axis, an image rotator comprising a prism that can invert an image, the prism disposed within the image rotator, and another rotation mechanism permitting rotation of the roof prism about an optical axis of the image rotator.

Optical lens systems

An afocal Galilean attachment lens is disclosed, with the lens comprising, along an optical axis, a first lens group with overall negative optical power and a second lens group with overall positive power. The first and second lens groups are arranged to define a Galilean configuration. The lens also has exit and an entrance pupils with respective diameters Dand Dthat define a pupil magnification PM=D/Dand in some embodiments PM&#x3e;10. The afocal Galilean attachment lens also has a length parameter defined LP&#x3e;200 and in some embodiments LP&#x3e;700. The extreme length of the afocal Galilean attachment allows for photographing or filming objects that are remote or otherwise hard to photograph while also providing a relatively large depth of field.

Growing community of inventors

Wingham, Australia

James Albert Frazier