A new development in optics brings benefits to machine vision applications previously only available to CCTV users. The new 1/2inch, 4–12mm (F/1.4) megapixel varifocal lens from Tamron, now available from Firstsight Vision (which will be known as Stemmer Imaging from 2009), combines megapixel resolution imaging capabilities with flexibility of mounting in production line environments.
Fixed-focus lenses are traditionally used in production line environments on the basis that the product to be inspected is of a consistent height. However, varifocal lenses are suitable for inspection lines that might be used for a number of different products. In addition, the varifocal capability may be of benefit if there is little flexibility in the mounting position for the camera, since the focal length can be adjusted to suit the application.
Available in both manual and DC Auto Iris models, the lens features advanced optical designs employing aspheric elements and LD (low-dispersion) glass to minimise aberrations and deliver superb image quality, with uniformly high resolution and contrast from the centre to the edges of the image field. This allows the full resolution of megapixel cameras to be realised.
Further uses for these new lenses include general surveillance and traffic applications. The high-quality optical performance ensures excellent resolution even in the corners of the image field. In addition, an angle of view in excess of 100degrees is possible at the widest angle (4mm) setting, thereby reducing the number of cameras required for comprehensive surveillance.