Other

Caldwell Photographic, Inc.

Fm-assets, Pty Ltd

J Brian Caldwell

Wilfried Bittner

James Albert Frazier

Erwin Scholz

Wilfried Aloie Anton Bittner

An anamorphic objective having a relatively small anamorphic factor but with relatively pronounced residual anamorphic artifacts is formed by reducing the anamorphic factor with anamorphic lens elements located on the image side of the aperture stop. The lens section on the object side of the aperture stop must therefore have a relatively large anamorphic factor, and this creates the desired residual anamorphic artifacts. The disclosed anamorphic objective is suited either to an integrated optical design or to a modular approach in which the anamorphic factor reduction optics are connected as a removable attachment to an independently well-corrected anamorphic optical system. The anamorphic objective has a relatively small anamorphic squeeze ratio while simultaneously producing relatively large residual anamorphic characteristics.

Anamorphic optical system wity relative small squeeze ratio but with relatively pronounced residual anamorphic characteristics

An optical attachment having five or six elements and configured to be operably arranged on the image side of an objective lens to reduce the focal length and focal ratio of the objective lens is disclosed. The optical attachment is particularly suitable for adapting objective lenses designed with a relatively large working distance for a large format size to cameras having a smaller format size and relatively small permissible working distance. The optical attachments disclosed herein have high image quality at large aperture over a large field of view, and can be well-corrected for all major aberrations.

Optical attachment for reducing the focal length of an objective lens

An optical attachment configured to be operably attached to the image side of an objective lens to reduce the focal length and focal ratio of the objective lens. The focal-reducing attachment includes four lens elements and has a magnification of between 0.5 and 1. The focal-reducing lens can work with objective lenses having relatively large working distances for a large format size as well as with cameras having a smaller format size and relatively small permissible working distance.

A tilt shift lens adapter having an adapter body with first and second body portions configured to provide precision tilting and shifting functions is disclosed. Opposite sides of the adapter body are configured to respectively engage a camera and a lens. Tilting and shifting are precisely controlled using precision tilting and shifting mechanisms. The tilting mechanism includes a neutral setting for ensuring precise parallelism between the lens and camera flanges when required. The adapter includes a mount to provide good balance and holding strength when heavy lenses are attached. An optional aperture adjustment mechanism manually adjusts lenses having no aperture ring.

Tilt shift lens adapter

Large aperture optical systems that are extremely well corrected over a large flat field and over a large spectral range are disclosed. Breathing and aberration variation during focusing are optionally controlled by moving at least two groups of lens elements independently. Aberration correction in general is aided by allowing the working distance to become short relative to the format diagonal. Field curvature is largely corrected by a steeply curved concave surface relatively close to the image plane. This allows the main collective elements to be made of low-index anomalous dispersion materials in order to correct secondary spectrum. In wide-angle example embodiments, distortion may be controlled with an aspheric surface near the front of the lens.

Large aperture imaging optical 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

Petersburg, VA, United States of America

J Brian Caldwell