Photometrics Data for Selected Instruments
| Instrument Type | Lamp Wattage |
Beam angle in Degrees |
Conversion Factors* | |||
| Diameter | Foot Candles | |||||
| Fresnel Spot | ||||||
| 3" | Spot | 150 | 16 | 0.28 | 6,500 | |
| Flood | 58 | 1.11 | 1,600 | |||
| 6" | Spot | 500 | 16 | 0.28 | 75,000 | |
| Flood | 52 | 0.98 | 12,000 | |||
| 8" | Spot | 1000 | 11 | 0.19 | 100,000 | |
| Flood | 48 | 0.88 | 12,000 | |||
| Ellipsoidal Reflector Spotlight | ||||||
| Strand 50° | 1000 | 53 | 0.92 | 46,000 | ||
| Strand 40° | 1000 | 38 | 0.62 | 90,000 | ||
| Strand 30° | 1000 | 30 | 0.5 | 121,000 | ||
| Strand 20° | 1000 | 20 | 0.35 | 184,000 | ||
| Strand 15° | 1000 | 12 | 0.25 | 250,000 | ||
| Altman 4.5x6.5 | 750 | 55 | 1.04 | 38,000 | ||
| Altman 6x12 | 750 | 26 | 0.46 | 114,000 | ||
| Altman 6x16 | 750 | 19 | 0.33 | 139,000 | ||
| Par 64 Spotlights | ||||||
| WFL | Long Axis | 1000 | 71 | 1.43 | 40,000 | |
| Short Axis | 45 | 0.82 | ||||
| MFL | Long Axis | 1000 | 44 | 0.8 | 125,000 | |
| Short Axis | 21 | 0.37 | ||||
| NSP | Long Axis | 1000 | 26 | 0.46 | 330,000 | |
| Short Axis | 14 | 0.24 | ||||
| VNSP | Long Axis | 1000 | 24 | 0.42 | 400,000 | |
| Short Axis | 10 | 0.17 | ||||
| Beam Projector | ||||||
| 10" | Spot | 1000 | 15 | 0.26 | 200,000 | |
| Flood | 25 | 0.44 | 95,000 | |||
| * To calculate beam diameter at any distance multiply distance by the conversion factor for diameter. | ||||||
| To calculate Peek Illumination at any distance divide conversion factor for Foot Candles by the distance squared. | ||||||
| Instrument Type | 10 feet | 15 feet | 20 feet | 30 feet | 40 feet | 50 feet | 60 feet | |||||||||
| F.C. | DIA. | F.C. | DIA. | F.C. | DIA. | F.C. | DIA. | F.C. | DIA. | F.C. | DIA. | F.C. | DIA. | |||
| Fresnel Spot | ||||||||||||||||
| 3" | Spot | 65 | 2.8 | 29 | 4.2 | - | - | - | - | - | - | - | - | - | - | |
| Flood | 16 | 11.1 | - | - | - | - | - | - | - | - | - | - | - | - | ||
| 6" | Spot | - | - | 333 | 4.2 | 188 | 5.6 | 83 | 8.4 | 47 | 11.2 | 30 | 14 | 21 | 16.8 | |
| Flood | 120 | 9.8 | 53 | 14.7 | 30 | 19.6 | - | - | - | - | - | - | - | - | ||
| 8" | Spot | - | - | - | - | - | - | 111 | 5.7 | 63 | 7.6 | 40 | 9.5 | 28 | 11.4 | |
| Flood | 120 | 8.8 | 53 | 13.2 | 30 | 17.6 | 13 | 26.4 | - | - | - | - | - | - | ||
| Ellipsoidal Reflector Spotlight | ||||||||||||||||
| Strand 50° | 460 | 9.2 | 204 | 13.8 | 115 | 18.4 | 51 | 27.6 | - | - | - | - | - | - | ||
| Strand 40° | 900 | 6.2 | 400 | 9.3 | 225 | 12.4 | 100 | 18.6 | 56 | 24.8 | - | - | - | - | ||
| Strand 30° | 1210 | 5 | 538 | 7.5 | 303 | 10 | 134 | 15 | 76 | 20 | 48 | 25 | - | - | ||
| Strand 20° | - | - | 818 | 5.2 | 460 | 7 | 204 | 10.5 | 115 | 14 | 74 | 17.5 | 51 | 21 | ||
| Strand 15° | - | - | - | - | - | - | 278 | 7.5 | 156 | 10 | 100 | 12.5 | 69 | 15 | ||
| Altman 4.5x6.5 | 380 | 10.4 | 169 | 15.6 | 95 | 20.8 | 42 | 31.2 | - | - | - | - | - | - | ||
| Altman 6x12 | 1140 | 4.6 | 507 | 6.9 | 285 | 9.2 | 127 | 13.9 | 71 | 18.5 | 46 | 23.1 | - | - | ||
| Altman 6x16 | - | - | 618 | 5 | 348 | 6.6 | 154 | 10 | 87 | 13.4 | 56 | 16.7 | 39 | 20.1 | ||
| Instrument Type | 10 feet | 15 feet | 20 feet | 30 feet | 40 feet | 50 feet | 60 feet | |||||||||
| F.C. | DIA. | F.C. | DIA. | F.C. | DIA. | F.C. | DIA. | F.C. | DIA. | F.C. | DIA. | F.C. | DIA. | |||
| Par 64 Spotlights | ||||||||||||||||
| WFL | Long Axis | 400 | 14.3 | 178 | 21.5 | 100 | 28.6 | 44 | 42.9 | - | - | - | - | - | - | |
| Short Axis | 8.2 | 12.3 | 16.4 | 24.6 | - | - | - | |||||||||
| MFL | Long Axis | 1250 | 8 | 556 | 12 | 313 | 16 | 139 | 24 | 78 | 32 | - | - | - | - | |
| Short Axis | 3.7 | 5.5 | 7.4 | 11.1 | 14.8 | - | - | |||||||||
| NSP | Long Axis | - | - | 1467 | 6.9 | 825 | 9.2 | 367 | 13.8 | 206 | 18.4 | 132 | 23 | 92 | 27.6 | |
| Short Axis | - | 3.6 | 4.8 | 7.2 | 9.6 | 12 | 14.4 | |||||||||
| VNSP | Long Axis | - | - | - | - | 1000 | 8.4 | 444 | 12.6 | 250 | 16.8 | 160 | 21 | 111 | 25.2 | |
| Short Axis | - | - | 3.4 | 5.1 | 6.8 | 8.5 | 10.2 | |||||||||
| Beam Projector | ||||||||||||||||
| 10" | Spot | - | - | - | - | 500 | 5.2 | 222 | 7.8 | 125 | 10.4 | 80 | 13 | 56 | 15.6 | |
| Flood | - | - | 422 | 6.6 | 238 | 8.8 | 106 | 13.2 | 59 | 17.6 | 38 | 22 | - | - | ||
| Instrument Type | 10 feet | 15 feet | 20 feet | 30 feet | 40 feet | 50 feet | 60 feet | |||||||||
| F.C. | DIA. | F.C. | DIA. | F.C. | DIA. | F.C. | DIA. | F.C. | DIA. | F.C. | DIA. | F.C. | DIA. | |||
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Western Michigan University
Comments to: matt.knewtson@wmich.edu
Revised : August 2004