Visual inspection can help compare two different systems but does not always validate results. Additionally, individuals that regularly look at these targets may have trained their brains to interpolate details not actually present due to viewing the target’s repetitive patterns. Someone with 20/20 vision is typically capable of discerning higher resolution or more detail than someone with 20/25 or 20/30 vision. Note that the results of using a test target are subjective if only viewed visually using visual observation is dependent on who is looking at the target. Because image quality can be defined by different components, particularly resolution, contrast, modulation transfer function (MTF), depth of field (DOF), or distortion, different systems may require different targets. This includes troubleshooting a system benchmarking, certifying, or evaluating measurements or establishing a foundation to ensure multiple systems work well with one another.

Test targets help determine the performance of an imaging system.

Siemens star testchart