Read the sheet in the order it is installed
Most IP67 gobo projector sheets list ten numbers and leave out the three that decide the result. Work from the wall backwards — image size, throw distance, ambient light — and treat everything else as supporting detail. The numbers that matter are the ones you can verify on site with a tape measure and a lux meter.
Output numbers, ranked by how much they lie
Wattage tells you the running cost, not the result. Two IP67 gobo projector models at the same wattage can differ by 30% at the wall because of lens efficiency and LED binning. What you actually care about is contrast: the image needs to be meaningfully brighter than the surface it lands on, and that is a lux comparison, not a lumen one.
The two numbers that must be quoted together
The useful specification is the throw ratio, or failing that a distance-to-image-width table. On a typical IP67 gobo projector covering 8–40 m, the zoom lens might take the image from roughly 0.8 m wide at the near end to 3 m at the far end. Once you know the width you need, the throw tells you where the bracket goes — not the other way round.
| Throw | Typical image width | Practical note |
|---|---|---|
| Short, around 8 m | 0.5 – 1.5 m | Bright and easy — most indoor work |
| Mid, around 40 m | 1.5 – 3 m | Where lens quality starts to matter |
| Long, beyond 40 m | 3 m and up | Contrast fails before reach does |
The optical spec most sheets leave out
Two numbers govern the image: gobo image area and the resolution the lens can carry. Glass gobos can be engraved far finer than any IP67 gobo projector lens in this class will resolve, so the practical limit is optical. That is worth knowing before you pay for engraving detail nobody will see from 10 m away.
IP rating and electrical data
Ratings age. an IP67 gobo projector that left the factory rated IP67 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.
What a good supplier answers without hesitating
Ask for measured figures rather than calculated ones: image lux at a stated distance, image width at your throw, and the gobo image area. Then ask what happens when the unit needs servicing — whether the IP67 gobo projector can be opened on site without voiding the rating, and how quickly artwork can be re-cut if a branch changes its logo.
