New Dual Sensor Camera Offers Unique Imaging Capabilities

Stemmer Imagings’ latest camera offering, the JAI AD-081CL, features two monochrome progressive scan CCD sensors mounted to a custom-designed optical prism. The prism-based design enables the camera to simultaneously capture two channels of 30fps video of the same field of view to within one-quarter pixel accuracy. A choice of operating modes allows the camera to be used for high dynamic range, high-speed operation or particle imaging velocimetry. Particle Imaging Velocimetry (PIV) is a planar optical measurement technique which provides a means of measuring the velocity of seeded particles (~1 - 50 microns (in air)) in the flow of interest. With a single CCD camera, the laser illumination is pulsed and two sequential images are captured and analysed to track particle measurement. The dual sensor AD-081CL, however, features a unique PIV mode, which allows the cameras’ twochannel operation to capture three closely-spaced images on a single trigger instead of two. This provide 50% more data for improved analysis of ultra-fast events.

Independent control of shutter speed and/or gain for each channel of the AD-081CL provides the opportunity for wide dynamic range operation. One channel is adjusted for the bright output, while the other channel is tuned for lower light output. The two images can then be analysed separately or combined to produce a dynamic range nearly double the normal CCD response. This enables the camera to achieve dynamic range levels as high as 20-bits per pixel (~120 dB) in a linear fashion that avoids the noise, shutter, and compression issues found in other types of cameras. The versatile AD-081CL can also operate at an effective frame rate of 60fps. This is achieved by interleaving the images from the two sensors into a single output stream. This high-speed/low noise mode does not increase in the clock frequency of the camera itself, thus keeping clock noise to an absolute minimum.

Each sensor has 1024 x 768 pixel resolution and 8 or 10 bit pixel depth. The camera features two configurable Camera Link outputs, allowing single-cable operation or separate cables for each channel. Other features include partial scanning and vertical binning capabilities, as well as analog video output to support auto-iris lenses.