Most bad moving-head purchases are not bad fixtures. They are the right fixture bought for the wrong room: a 2° beam in a 4 m ceiling, a 22 kg three-in-one on a truss that gets climbed twice a week, an IP20 wash under a canopy that leaks. The fix is not a bigger budget — it is deciding in the right order. Here is the order we use.
1. Start with the room, not the catalogue
Three measurements decide more than any brochure: trim height (how high the fixture hangs), longest throw (how far it has to reach), and what the light has to land on — a performer, a wall, a floor, or nothing but haze.
- A 12 m trim and a 30 m throw is a beam and spot job. Narrow optics earn their keep because the throw is long.
- A 4 m trim in a 200 m² banquet hall is a wash and zoom job. A 2° beam there is a dot on the ceiling.
- If the venue will never run haze, cut the beam count. A beam with no haze is a very expensive spotlight.
2. The five numbers that decide the model
| Number | Why it decides the model | What to watch for |
|---|---|---|
| Power / output | Sets how much punch survives the throw | LED wattage is input power, not light output — compare beam angle and throw, not just watts |
| Beam angle | Sets the spot size at a given distance | 2–6° beam, 10–45° spot, 25–60° wash; zoom ranges are usually narrower than the marketing implies |
| Weight | Sets truss load, crew size and case size | A 22 kg fixture is a two-person lift; four of them change the rigging plan |
| IP rating | Sets where it can hang | IP20 indoor only; IP65 for rain-exposed and permanent outdoor |
| DMX channels | Sets how many fixtures fit one universe | 16–28 channels is normal; extended modes eat a universe fast |
3. Beam, spot, wash — or the three-in-one?
A beam makes a hard column you see in haze. A spot makes a shape you can focus and cut with gobos. A wash covers an area evenly. They are three points on one optical continuum, not three products, and the mix matters more than the individual fixture. If you are still deciding the split, our beam vs spot vs wash breakdown covers the angle maths and the fixture mix for bars, banquet halls and auditoriums.
A three-in-one (often sold as BSW) is the pragmatic answer when the rig has to do everything with a fixed fixture count. It is the wrong answer when one job dominates: a touring beam package that also has to cut gobos will always compromise one of the two.
4. Touring versus installed: two different products
| Touring / rental | Installed / fixed | |
|---|---|---|
| Priority | Weight, case fit, fast service | Quietness, service access, long life |
| Housing | Road-ready, quick-release clamps | Clean mounting, hidden cabling |
| Noise | Tolerable | Fan noise is a specification — check it at low output, not full |
| IP rating | IP20 in a truck is fine | IP65 if it is permanent and outdoors |
The same wattage can be a good touring fixture and a poor install fixture, or the reverse. Ask which life the fixture will live before choosing the model.
5. What the datasheet will not tell you
- Noise at low output. Most fixtures are quiet at 30% and loud at 100%. Wedding venues live at 30%.
- Service access. Can the fan be changed on a ladder, or does the fixture come down? Ask for the exploded view.
- Colour consistency across units. Two fixtures of the same model should match in a white wash. That is a binning question, not a spec-sheet number.
- Spare parts lead time. A fixture you cannot service in three years is a rental liability.
6. A quote-ready checklist
| # | Question | Why it goes on the quote |
|---|---|---|
| 1 | Trim height and longest throw | Fixes the beam angle and output class |
| 2 | Will the venue run haze? | Decides whether beam fixtures earn their cost |
| 3 | Does anything need to land as an image? | Decides gobo spot or not, and metal versus glass gobo |
| 4 | Is there a camera? | Flicker-free output and colour temperature become requirements |
| 5 | Indoor, covered, or rain-exposed? | Fixes IP20 versus IP65, and the connector type |
| 6 | How many fixtures per universe? | Decides channel mode and console load |
| 7 | Who services it, and how do they reach it? | Weight and mounting become part of the spec |
| 8 | What is the room doing on a normal night? | The only question that keeps the spec honest |
7. Five mistakes we see every month
- Buying beams for a room with no haze. They become spotlights with a bad zoom range.
- Comparing wattage instead of beam angle at the throw distance. 380 W at 2° and 380 W at 20° are different tools.
- Ignoring weight until rigging day. Truss capacity and crew size are physical limits, not opinions.
- Specifying IP65 for a covered stage. You pay for seals and service complexity you do not need.
- Forgetting the console. 24 fixtures at 28 channels each is 672 channels before you add anything else.
8. What to put in the RFQ
A short, specific RFQ gets you comparable quotes instead of three different products. Five lines are enough: quantity and position (truss / floor / wall), trim height and longest throw, indoor or outdoor with the exposure described, required functions in priority order (beam, gobo, wash, zoom), and the control protocol you already run. Add the fixture weight limit if the truss is existing, and ask for the channel count in the mode you intend to use — not the maximum.
Suppliers who answer all five with numbers are quoting the same job you are. Suppliers who answer with a brochure are quoting a different one.
Answer the eight questions and the model usually chooses itself. The remaining decisions — brand, colour system, zoom range — get easier, because by then you are comparing fixtures that could actually do the job.
Want a fixture list instead of a catalogue? Send us the trim height, room dimensions and what the space has to do on a normal night. We will come back with a beam / spot / wash split, a fixture count and the models that fit the budget.