Question about Philips Hue Ensis

The ceiling mounted mounting box allows the height of each of the two cables to be adjusted individually to the desired height.
The minimum height is the space needed to move the top cover and access the length control system, I think it could be less than 30cm or even 20cm. For the record, the maximum length should be close to 2m, which allows it to be mounted in rooms with (very) high ceilings.
On the other hand, as the lamp lights up and down, I would recommend more than 45cm, but that's a matter of taste (and ceiling height... :-D).

Quite possible, we installed them at about 15cm.