Recently an architect told me that light was a subject he didn't know much about. Either he was talking in an extremely technical sense, or he was exceptionally honest, or he was extremely unusual. For most architects, light forms part of a trinity, alongside materials and form. But of the three, light is certainly the trickiest.
In a carefully considered drawing, you can show how one material meets another and - with luck and a decent builder - your vision may be realised exactly. But light is much more elusive, dependent on the source - whether natural or artificial - on filtering, and on reection.
And, like landscape, light cannot be defined at the beginning and then expected not to change. Weather will have an effect, as will people - those pesky realities who do so much to mess up a perfect vision. They open and close blinds, switch lighting on and off, and even wear unsuitably reective clothes or neglect to wash the windows.
Only in an entirely controlled environment, with no element of individual control over artificial lighting and no natural light, can the original vision of the architect remain unsullied.
And what a vision that would be - anyone for Alcatraz?
Yet the rewards from skilful use of lighting can be great. For example, look at the way that Eva Jiricna carefully chose the material for the underside of the balconies on her Prague villa (pages 13-28) to reect the light.
Our focus this month on lighting ranges from a new way of introducing natural light to tips on ensuring that your LEDs don't let you down. And, to continue our leitmotif, in the Designer Profile, Matt Schreiber talks to Will Hunter about working with artist James Turrell to realise his visions, which seem too numinous to have done anything but just landed from another dimension. I hope you find this an illuminating issue.