Note: IP camera lens technology has moved on since the publication of this article. However, P-Iris lenses remain in use.
P-iris is an automatic iris control system developed by Axis Communications, designed to give precise control over the iris opening using a stepper-motor driven iris and specialised software. The P-iris system has been developed to make improvements over the traditional auto-iris by giving better control over the aperture.
In bright conditions an auto-iris lens may be subject to blurring caused by diffraction. This is when the surrounding light levels cause the iris to close too much. This is even more noticable in megapixel cameras where the pixel size in the image sensor is a lot smaller than conventional standard definition cameras.
This has led to Axis developing an iris system where the user has greater control over the aperture and by doing so has provided greater image quality with higher contrast, increased clarity, higher resolution and better depth of field control.
P-iris is expected to replace the DC-iris as the standard method of iris control in fixed Axis network cameras.
Image on left shows traditional lens, image on right shows the new P-iris lens demonstrating better depth of field control