Working with Footcandles
Although the Footcandle is the most common unit of measurement used by lighting professionals in the United States, The Illuminating Engineering Society of North America (IES) makes specific recommendations for different building application which are summarised by Skyco Skylights.
Footcandles are the most common units of measurement used by lighting professionals, and can be measured by using a light reader whilst standing directly under a light source.
Footcandle recommendations are determined by the type, purpose, and end-usage of any building (as well as its stage of construction), and the following table summarise key guidance from IES.
FOOTCANDLE RECOMMENDATIONS
| Assembly | Footcandles |
| Rough easy seeing | 20-75 |
| Rough difficult seeing | 75-100 |
| Medium | 100-200 |
| Fine | 200-500 |
| Extra fine | 500-1000 |
| Automobile Manufacturing | |
| Final assembly, finishing, inspecting | 200 |
| Body & chassis assembly | 100 |
| Body parts manufacturing | 100 |
| Frame assembly | 50 |
| Clothing Manufacturer | |
| Receiving, storing, shipping | 20-50 |
| Pattern making, trimming | 50-100 |
| Shops, marking | 50-200 |
| Cutting, pressing | 100-500 |
| Sewing, inspection | 200-500 |
| Food Service Facilities | |
| Dining areas | 5-20 |
| Food displays | 30-100 |
| Kitchen | 50-100 |
| Gymnasiums | |
| Assemblies | 10 |
| General exercise and recreation | 30 |
| Exhibition, matches | 50 |
| Hotels | |
| Lobby, general lighting | 10-20 |
| Front desk | 50-100 |
| Reading and working areas | 20-50 |
| Machine Shops | |
| Rough bench | 20-50 |
| Medium bench, rough grinding | 50-100 |
| Fine bench work | 200-500 |
| Material Handling | Footcandles |
| Loading trucks | 10-20 |
| Picking stock, classifying | 20-50 |
| Wrapping, packing, labeling | 20-50 |
| Offices | |
| Accounting | 50-100 |
| Audio-visual areas | 20-50 |
| Conference areas | 20-70 |
| Corridors | 20 |
| Drafting | 50-200 |
| General and private offices | 50-100 |
| Schools | |
| Reading | 20-100 |
| Typing | 20-100 |
| Demonstrations | 100-200 |
| Sheet Metal Work | |
| General | 100 |
| Tin plate inspection, scribing | 100-200 |
| Stores | |
| Merchandising, serviced | 30-100 |
| Merchandising, self-serviced | 200 |
| Warehousing, Storage | |
| Rough bulky | 10-20 |
| Medium | 20 |
| Fine | 20-50 |
| Welding | |
| General | 20-50 |
| Woodworking | |
| Rough sawing, rough bench work | 20-50 |
| Sizing, sanding, medium bench work | 20-50 |
| Fine bench work, finishing | 50-100 |
| Note: Footcandles over 200 require specialty lighting. |
