P-Iris (Precise Iris)
The combination of all of these settings ...
Accurate Iris control
Accurate Iris control through the use of a stepper motor with constant confirmation feedback
Dynamic gain control
Dynamic gain control to ensure the image signal level is optimised, without compromising the image quality
Responsive exposure settings ensuring the right amount of light reaches the sensor, whilst maintaining image sharpness
... is what makes the P-Iris so much more precise than just opening or closing the aperture in response to variations in light.
On of the cameras in our portfolio that contains this level of control is the Spark series from JAI.
The automatic level control technology (ALC), designed by JAI, is an advanced auto exposure function that’s targeted for outdoor vision applications where the changes in light call for a challenging combination of settings. This works very well in traffic and security applications.
The ALC combines the gain and shutter control to achieve optimal exposure, whilst minimising noise and motion blur.
Under dark conditions, the exposure time is fixed to a preselected value, selected by the user, to avoid unacceptable motion blur. Simultaneously, the gain is increased to achieve an acceptable exposure level whilst being limited by the maximum amount of noise that is acceptable.
At the other extreme, as illumination increases, the gain reduces until it reaches zero, eliminating any noise that was introduced. And yes, the exposure time adjusts simultaneously, reducing itself until it reaches the acceptable minimum.
The ALC interface gives you the flexibility to adjust it all to accommodate the dynamic lighting conditions. The controls even allow you to specify which portions of the image to use when making its calculations. So, for example, in vehicle-mounted applications, the window can be set to not include the sky when it's making the calculations. You can even set the speed at which the camera reacts to changing conditions, and the type of algorithms used when making the calculations.