The OS200B can test positive lenses, negative lenses, and afocal modules, and tests can be done at infinity or at finite conjugates. While the base system is configured for an on-axis testing, options are also available for off-axis testing. The lens under test forms an image of the pattern on a test reticle and the image is captured by a FireWire video camera for analysis. There are two basic sources supplied- a collimator for testing and a back-lit reticle for testing at finite conjugates. There are two basic detectors- a telescope for viewing virtual images at infinity and a microscope for viewing real images. The base system includes a 400 mm collimator that supports testing of lenses with CA up to 45 mm. Larger collimators are available up to 100 mm CA.