Survey before you drill
Installations go wrong in the first hour, on the survey, when somebody decides where the bracket goes before checking what is behind the wall. Before you drill for a gobo projector, confirm four things: the power position, what the surface is made of, whether the mounting point can carry the weight, and where the image will actually land once the furniture and signage are in place.
- Power within reach of the mounting point
- What the target surface is made of and how it is lit
- Whether the mounting point carries the weight
- Access for future servicing — ladder or powered platform
Getting the geometry right before it is fixed
Mounting height is a compromise between throw angle and accessibility. A gobo projector mounted flat-on to the wall gives the squarest image, but the further off-axis it sits the more keystone distortion you get — the image becomes a trapezoid. Keep the beam as close to perpendicular as the site allows, and prefer a position you can reach with a short ladder rather than a cherry picker.
- Bracket rated above the fixture weight
- Stainless fixings for exposed positions
- Beam as close to perpendicular as the site allows
- Position reachable without powered access
Aiming, zooming and focusing
Focus on the centre, then check the edges. A gobo projector focused on a flat wall should read evenly corner to corner; if it does not, the usual cause is an angled mount rather than a bad lens. Once you are happy, lock the focus if the unit allows it, because vibration and thermal cycling will otherwise move it over a season.
- Set the bracket position first
- Zoom to frame the image on the surface
- Focus at the centre, then check all four corners
- Lock the focus if the unit allows it
Power, cable routing and switching
Route the cable as if somebody will try to unplug it, because somebody will. Use a switched, protected supply, keep the run out of reach where possible, and make sure the connection point is accessible for service without dismantling the gobo projector. If the install is outdoors, the cable entry — not the housing — is the most likely place for water to get in.
Commissioning checks
Test the way it will be used, not the way it was installed. Run the gobo projector at the hour it is meant to run, with the house lights at their normal setting, and look at the image from where the audience will stand. A unit that looks fine at 2pm in an empty room can be invisible at 7pm with the lights on.
- Image sharpness at the centre and all four corners
- Contrast against the surface at the working hour
- Full duty cycle run without thermal cut-out
- Housing temperature after an hour at full output
Handover notes worth leaving behind
Write down the settings. A gobo projector reinstalled after decoration, or a second unit ordered to match the first, is only reproducible if somebody recorded the throw, the lens setting and the gobo reference. Put it in the site folder and send a copy to whoever will order the replacement.
- Throw distance and image width as installed
- Gobo reference and artwork file name
- Zoom and focus settings
- Supplier contact for re-cutting artwork
