( ( ( Two wavelengths ) ( of ( light ( , ( ( red and ) infrared ) ) ) ) ) ( ( are used ) . ) )
(ROOT (S (NP (NP (CD Two) (NNS wavelengths)) (PP (IN of) (NP (NN light) (, ,) (NN red) (CC and) (NN infrared)))) (VP (VBP are) (VP (VBN used))) (. .)))
Two wavelengths of light, red and infrared are used.
(ROOT (S (NP (NP (NNP Light)) (PP (IN with) (NP (DT the) (JJS longest) (NNS wavelengths)))) (VP (VBZ is) (VP (VBN called) (NP (JJ infrared) (NN light)))) (. .)))