Three consonants follow light: it passes through glass, it bounces back as a reflection, and it lets you look out at the world. From this one root come the glasses on your nose, the transparency we demand of institutions, and your whole outlook on life. To see through, to mirror, to observe: one family of light. Every word here is verified against pealim, niqqud included.
The same root runs through the verb system. Each binyan is a voice: it bends the one idea into active, passive, causative or reciprocal. Tap to hear.
The pi'el לְשַׁקֵּף (to reflect / X-ray) is the intensive that throws light back, while the hif'il לְהַשְׁקִיף is the directed gaze, to look out over something. The pa'al, nif'al, pu'al, huf'al verb slots stay empty here; the reflexive idea surfaces as the noun הִשְׁתַּקְּפוּת below.
Same root letters, different noun moulds (mishkalim). The mould tells you the function: who does it, the act of doing it, or the thing produced.
Strip the prefixes, suffixes and vowels. Three consonants remain, and the meaning lives there.