AMP aims to bring high dynamic range to videographers
By Ben Coxworth
June 27, 2011
It's a conundrum every serious photographer faces ... do you set your exposure so that the brightest objects in a scene are properly exposed but the darkest are underexposed, or so that the darkest are properly exposed but the brightest are overexposed? Or do you go with some compromise, where only the half-way-between objects look right? That's where high dynamic range (HDR) cameras come into play. Combining several levels of exposure in one shot, they act like the human eye, allowing properly-exposed dark and bright objects to co-exist within the same picture. Now, New Mexico's Contrast Optical Design & Engineering is set to release its AMP camera, for shooting HDR video.
First of all, this isn't the first time that HDR video has been achieved. The effect was created last year by combining the output of two Canon DSLRs, and then this January, a team from the University of Warwick announced the development of a purpose-built prototype HDR video system.
The AMP system utilizes a patented optical engine to split the light from a single lens onto three digital video sensors. While identical in composition and shutter speed, the resulting three 1080p images are exposed at increments of approximately 3.5 stops, relative to one another. This means that every frame of video contains information for three different levels of exposure, the raw data being stored on an onboard solid state drive - at 30 fps, 256GB will hold somewhere over 30 minutes of footage.
Users can then manually combine those exposure levels within a single shot, to achieve the desired effect.
"Our camera system does not automatically tonemap the image: it simply produces HDR images for every frame of video, and it is up to the user to apply their favorite tonemap algorithm(s) to the HDR images so they can be displayed," Contrast's Chief Technical Officer Michael D. Tocci explained to us. "The Gen2 camera will have the capability to perform tonemapping in the camera in real time (in order to provide an HDMI video stream), but this again is a tonemap operator that is open for the user to change and customize as they see fit."
The current AMP prototype is reportedly about the size of a prosumer SLR, and weighs under 5 pounds (2.27 kg) without a lens. Apart from a power and record button, all of the controls and displays are located on a separate Bluetooth unit. A limited production run of the second-generation AMP cameras is set for the end of this summer (Northern Hemisphere), although none of them will be available for purchase by the general public. Film-makers and/or broadcasters who would like to rent or borrow one, however, can get on a waiting list by visiting the AMP website. If there is enough interest, the second run of cameras will be larger.
The video below shows some examples of what the system can do.