A Lower Head Range
25-35mm, where most 35x45mm specs say 32-36mm.
Cambodia publishes a head range of 25mm to 35mm from the bottom of the chin to the top of the head, with the eyes sitting roughly 60-70% up from the bottom of the image.
That is wider and lower than the usual 32-36mm for this frame size. In practice it means a slightly smaller head is fine here, and a head at the very top of the ICAO range — 36mm — is over Cambodia's ceiling. Aim mid-range and you satisfy both.
