This results in inverted polarity of the stripe pattern: black stripesin the place of white stripes and vice versa and further polarity inversions occur further inward. Spurious resolution appears similar to aliasing, but it is a purely optical phenomenon, so it occurs without need of pixels. Under optical blur from defocus, a Siemens star like any periodic pattern lets rise to the phenomenon of spurious resolution above the resolution limit, i.e. They are useful in drawing the eye to a ingredient on the page. Siemens stars are similar to the Japanese Naval Ensign, Russian Air Force flag and Jordanian Royal Standard. it is also used during film or video shoots to guide setting the focus in special situations.

In the field of video production, where this is the often called a back focus chart, the Siemens star is widely used to reshape the back focus of removable lenses. Similarly, it can be applied to a camera's optical resolution by taking photographs of a Siemens star printed at high resolution & comparing photographs from different cameras, to see which retained the center bit the closest.

A Siemens star, or forwarded target, is a device used to test the DPI.

High resolution siemens star