Patent Application
20190149717
The present invention relates to the correction of polarization and light correction in photography and videography. Specifically, it relates to remote control of polarizer camera filters and other optical devices.
Drones and other unmanned vehicles are used recreationally and to perform professional tasks. Cameras are integrated into or can be attached to drones. Drones allow a photographer or videographer to conveniently capture aerial footage. Image and command data can be transferred between the operator and the drone and drone camera via remote control, or other transponder or transceiver. User interfaces displaying the footage captured by the drone are either integrated into the control system or attached thereto.
High quality photography requires the use of lens filters to modify the light penetrating the camera lens. Polarizer filters improve image contrast and saturation and reduce glare from reflections by correcting the polarization of light caused by specular reflections and atmospheric scatter. These problems are particularly acute in aerial footage, as atmospheric scatter can cause attenuation of sky color and reflection can be intensified by distance and vantage point. Though software programs can eliminate many visual flaws, polarized light is not separately recorded by cameras and software programs are not capable of correcting the unwanted polarization. This makes correct filtration of polarized light at the time of filming necessary.
Polarizer filters improve image quality by absorbing polarized light. Polarization occurs when light waves travel in directions non-perpendicular to the camera lens. The polarizer is set over the lens at the angle allowing for maximum absorption of polarized light. The filter is rotated around the polarization axis located in the center of the light transmissive element and perpendicular to the surface of the frame. The polarizer allows adjustments within a range of angles relative to the polarization axis, accounting for the angle of incidence to the sun. Before applying the filter to the camera, a photographer can determine the appropriate angle by looking through the filter and rotating it. The filter can then be applied to the camera, with further adjustments if necessary.
Drone photography presents unique problems in determining and maintaining the correct level of polarization filtration. First, when applying the filter, the photographer must determine the appropriate polarization angle based on conditions on the ground. This angle can change across different elevations. Second, the correct angle of polarization will change during a flight of extended duration due to rotation of the earth. This can lead to in-flight increases in polarization, and lower quality photographs or video footage.
The present invention allows adjustment of a polarizer filter while a drone is airborne. The filter can be remotely rotated around the polarization axis while coupled with the drone camera. Necessary adjustments can be made in-flight via remote control based on aerial perspective and lighting changes as perceived by the photographer.
The exemplary embodiment includes a camera filter with a stationary component of the frame capable of coupling with the camera lens housing. An exemplary embodiment is a self-contained camera filter, capable of removable coupling with a DSLR camera, drone camera, or other image capture device. The frame surrounds polarizer glass, or a light transmissive element. The light transmissive element, is operatively coupled with the frame and rotated by a mechanical component. In the exemplary embodiment, the mechanical component is comprised of a drive ring and a crank drive. The drive ring is a circular implement within the frame. The drive ring is capable of rotation relative to the frame. The inner edge of the drive ring is conjoined with the outer edge of the light transmissive element.
The drive ring has a section of gear ridges on its outer edge. The outer edge of the frame wall has an open section allowing access to a control hub. The control hub contains the crank drive. The crank drive contains ridges that interlock with and exert rotational force on the gear ridges of the drive ring. The gear ridges extend over a sufficient distance to permit the necessary rotation of the light transmissive element to the orientation of desired polarization.
A receiver is enclosed in or positioned on the control hub. The receiver is a device capable of receiving and processing data transmitted from a remote controller. The receiver may be a radio frequency module, optical communications receiver, or other device capable of wireless communication, depending on the mode of transmission. In the exemplary embodiment the receiver is integrated into a circuit board assembly. The circuit board allows transmission of the command data from the receiver to the drive crank. The receiver and circuit board assembly comprise a transmission-reception component capable of receiving and converting data from signal or transmission form to command form capable of actuating movement of the drive ring.
A remote controller is capable of wireless transmission of data with the receiver and drone camera. The remote controller is a downlink receiver for image data transmitted from the drone camera and an uplink transmitter of command data to the receiver. The exemplary controller includes a user interface. The user interface can display the image data from the drone camera. The remote controller also has input components, i.e. buttons, icons, etc., enabling the operator to input commands. Based on the command input, the crank drive engages and rotates the drive ring around the polarization access to the desired orientation. Rotation through the entire polarization spectrum is possible. When the light transmissive element is in the desired position the drive ring and crank drive are locked in place, creating the stability required for high quality photography. The filter may access the drone or camera's energy source. Alternative embodiments may contain their own battery or alternative energy source.
Alternative embodiments may rotate the frame relative to the camera lens housing. This may include a mechanical component capable of exerting transverse force on the lens housing as means of rotating the frame.
An alternative embodiment may rotate the camera lens housing relative to the camera or other optical device to achieve the desired polarization angle. The drive ring would be located on the camera lens housing, or the camera lens housing would be a drive ring itself. The crank drive aspect can either be located on the outside, inside, or on the body of the camera. The crank drive can engage the drive ring to rotate the lens housing. The polarizer filter would remain stationary relative to the lens housing.
Alternative embodiments may utilize a different type of mechanical component or method to rotate the light transmissive element, such as electromagnetism. In an exemplary electromagnetic model, two anchor magnets of opposing polarities would be placed on the inside of the frame at the ends of the rotation range. Rotation magnets of the same polarity would be placed on drive ring at the ends of the rotation range. Command data activates the anchor magnet towards which rotation is desired. The drive ring locks in place when the commanded orientation is reached.
Polarizer filters are often combined with neutral density filters for enhanced image saturation capability. Alternative embodiments would allow removal and installation of light transmissive elements of different image altering capability. Interchangement of light transmissive elements would enable use of the same frame with light transmissive elements of different image alteration capabilities.
The receiver, circuit board assembly, and crank drive may be enclosed in the frame or camera body. Frame dimensions and alternative arrangements of the components may allow alternative configurations of the components relative to each other. The receiver may also transmit the command data to the crank drive wirelessly.
The control hub may have an opening to facilitate transmission of the command data to the receiver.
The prior art is depicted in
The circuit processor assembly 47 is connected to the crank drive 33. The circuit wires 49 permit transmission of the command data.
The foregoing discussion discloses and describes merely exemplary methods and embodiments. As will be understood by those familiar with the art, the disclosed subject matter may be embodied in other specific forms without departing from the essence or characteristics thereof. Accordingly, the foregoing disclosure is intended to be illustrative, but not limiting, of the scope of the invention, which is set forth in the following claims.
