Focal Distance

Definition:	This setting provides a means for configuring the focal distance of the imager. The input value is in terms of inches and is divided by 100 internally. For example, 400 sets the imager to a focal distance of 4 inches. It is important to note that the imager may not have an exact match for the focal position requested. The imager has a range of steps that are calibrated and mapped to focal positions. This input value is matched to the closest focal position step that the system supports. It is also important to keep in mind that the resolution of the system is not linear. As the imager's focal distance setting increases, the resolution decreases. This effect is offset somewhat by the fact that the depth of field increases at greater focal distances.
Serial Cmd:	<K525,focal distance>
Default:	Standard Density = 400 (4")
Options:	200 (2") to 600 (6")
Default:	Ultra-High Density = 400 (4")
Options:	200 (2") to 600 (6")

Note: In the factory, the imager calibrates its focus curve and matches the focus motor steps to various focal positions. Therefore, each imager has a slightly different focus map of stepper motor positions vs. focal positions. This allows the user to enter a focal distance that causes the imager to select the closest stepper motor position required to obtain the user-defined setting. In this way, there is consistency between imagers for any given focal distance input.

Note: To view a list of focal distances supported by your imager, use the <K526> command.