[Heb-NACO] ha-/he-afel

[Jasmin Nof]

Hi all,

I'm working on the title לפני השער האפל. In this case האפל is an 
adjective, so the relevant E-S entry is the one where the letter א is 
vocalized with a kamats (not the entry for the word as a noun, where the 
א is vocalized with a hataf-patah). Given this, shouldn't the 
vocalization of the heh ha-yedi'ah be a segol, as in he-afel? What am I 
missing?

The same question stands for the titles

הצד האפל של התפוח
הצד האפל של החמה
הצד האפל בצחוקו של שלום עליכם
רחוב החליל האפל

Thanks, Jasmin