Lighting system that can change light emitting characteristic and lighting device and lamp holder of the lighting system

A lighting system comprising:

• a carrier unit;
• and
• at least one lighting device removably supported on said carrier unit and including
• a lamp holder including a holder plate, and
• a first positioning plate and a second positioning plate extending from said holder plate and spaced apart from each other, and
• a light emitting unit mounted on said holder plate;
• wherein said first and second positioning plates are selectively and removably connected to said carrier unit, said holder plate being disposed at a first position when said first positioning plate is connected to said carrier unit, or being disposed at a second position when said second positioning plate is connected to said carrier unit, a light emitting characteristic of said light emitting unit when said holder plate is in said first position being different from a light emitting characteristic of said light emitting unit when said holder plate is in said second position.

A lamp holder comprising:

• a holder plate;
• and
• a first positioning plate and
• a second positioning plate extending from said holder plate and spaced apart from each other;
• wherein said holder plate being disposed at a first position when said first positioning plate is fastened, or being disposed at a second position where is different from the first position when said second positioning plate is fastened.