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Grading

Started by ghochrei-migration,

2 posts in this topic

  • Member: Seasoned Veteran
DWLange

DWLange

Posted
  • Member: Seasoned Veteran
Posted

A pinpoint light source is a narrow or directional light, such as one having a conical shade. NGC's graders use such lamps, with 75W-100W incandescent bulbs---the choice of power is a personal one for each grader.

 

An incandescent bulb is the traditional type in which a burning filament (metal fiber) provides the light.

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