Many of the best colony counters on the market are relatively easy to use. You will place your petri dish, slide, or other objects onto the main unit’s stage. The camera will then scan the object. The user can make adjustments to the machine to fine tune it. Many of the machines have an illumination stage. Since objects and backgrounds are different, it is important to tune the illumination method (transmitted, reflected, darkfield) that will work the best for your particular object.