These are simple really. Just a 450 mm length of 70 mm x 20 mm with a 70 mm square screwed to the bottom, braced with 45° wedges. Attached as seen in the pic’s. To get the right length for these I simply raised a box upwards toward the lights at their ceiling height until the lighting on it looked right and noted how far I would have to drop the lights to light the box on the bench.
As you can see they are held by two coach bolts at the top and the light is held onto the bottom of the extension by a further bolt through the base. Simple, maybe not elegant but they work.
The pictures for Cupcake were taken using this setup.
-- Martyn -- Boxologist, Pattern Juggler and Candyman of the visually challenging. http://www.theartofboxes.com