Start from the wall and work backwards
Nothing on a spec sheet is dishonest; plenty of it is irrelevant. A logo light projector sheet will quote lumen output, power draw and beam angle, but what you need is image width at your throw distance and contrast against the light already on the surface. Those require two more numbers the sheet usually does not give you, which is why they are worth asking for.
Output numbers, ranked by how much they lie
Three output figures get mixed up constantly: lumens describe what the lamp produces, lux describes what arrives on the surface, and watts describe what you pay for. A logo light projector drawing 15–120 W might deliver 3,000 lumens, but the lux at the wall depends entirely on how wide you spread it. The same lamp projecting a 1 m image is nine times brighter than the same lamp projecting a 3 m image.
The two numbers that must be quoted together
Throw distance without image width is meaningless, and plenty of sheets quote only one. A logo light projector that throws 18 m might give you a 1 m logo at that distance or a 6 m one, depending on the lens — a difference that decides whether the install works. Always ask for the pair: distance and the resulting image size.
| Throw | Typical image width | Practical note |
|---|---|---|
| Short, around 3 m | 0.5 – 1.5 m | Bright and easy — most indoor work |
| Mid, around 18 m | 1.5 – 3 m | Where lens quality starts to matter |
| Long, beyond 18 m | 3 m and up | Contrast fails before reach does |
The optical spec most sheets leave out
The spec most sheets omit is the maximum artwork resolution the optics can resolve. A logo light projector with a good lens will render fine detail that a cheaper unit turns to mush, which means the limiting factor is often the projector, not the gobo. If your design has thin strokes, ask what line width the system holds at your throw distance.
The compliance block
Ratings age. A logo light projector that left the factory rated IP44 can lose that rating the first time somebody opens it to change a gobo and reseats the gasket badly. Look for a design where routine access does not mean breaking the environmental seal, or accept that the rating applies to the unit as delivered, not as maintained.
Questions worth asking the supplier
The most revealing question is about failure. Ask what the most common warranty claim on this logo light projector is and how it is resolved. A supplier who answers honestly is worth more than one with a slightly better spec sheet.
