Boys start to get acne at the age of approximately 12 years, with a range of 9 to 15 years old. As most girls will attest, boys on average mature later than girls. Early on in the onset of teen acne, the main lesions are blackheads and whiteheads.
The angular size (angular diameter, apparent size) of an object as seen from a given point is the visual diameter of the object measured as an angle. The visual diameter is the diameter of the perspective projection of the object on a plane through its center that is perpendicular to the viewing direction.
resolution will be in the range of micrometers, but the maximum range is limited to only a few meters. Up to distances of 100m people often use the phase shift measurement. The laser light is modulated and the phaseshift between outgoing and incoming light gives the distance. To reach a resolution in the millimeter range very high sampling rates are necessary. Only low measuring rates with high current consumtion are possible the consequence. With Time-to-Digital-Converters (TDCâs) you choose the straight way. It is possible to measure directly the time-of-flight of light.