symmetrical confocal geometry
对称共焦几何

• contrast of luminance
• contrast rendition
• contrast reversal
• contrast sensitivity
• contrast transfer function 1
• contrat light compensating contrast micromether
• contravariant component of vector
• control
• control azimuth
• control ball
• control board
• control bus
• control buttion
• control center
• control circuit
• control disk
• control element
• control equipment
• control grid
• control-grid aperture
• control knob
• controllability
• controllable
• controllable diffraction grating
• controllable liquid-crystal display device