Last Updated 2 hours ago
Overview
The Type 3371 sits at the foot of a backing and throws a wash up the wall. With a 1,000 W FCM lamp set 6 ft from the cyc, Mole measured 120 fc at floor level and 45 fc at 16 ft. Moving the same lamp back to 8 ft reduces the hot spot near the floor and evens out the wash.
Key specifications
| Specification | Type 3371 |
|---|---|
| Maximum head load | 1,000 W |
| Supply rating | 120/240 V AC or DC, matched to the installed globe |
| Head dimensions | 8½ × 12 × 8⅞ in. |
| Weight with filter frame | 7½ lb (3.4 kg) |
| Reflector | Fixed Molebrite Alzak aluminium scoop |
| Socket | Double-ended recessed single-contact, T-3 |
| Filter frame | Type 33720, 10⅞ × 11⅞ in. |
| Control | External dimming or switching |
Replacement lamps
| Lamp codes | Per lamp | Supply | Rated colour | Current per lamp |
|---|---|---|---|---|
| FCM / FHM | 1,000 W | 120 V | 3,200 K | 8.3 A |
| EME / EMF | 800 W | 240 V | 3,200 K | 3.3 A |
| EJG / EMD | 750 W | 120 V | 3,200 K | 6.3 A |
| FDF / FDN | 500 W | 120 V | 3,200 K | 4.2 A |
| FCL | 500 W | 120 V | 3,000 K | 4.2 A |
| EHM / EHZ | 300 W | 120 V | 2,950 K | 2.5 A |
The original Groundrow sheet specifies a lamp length of 4 11/16 in. and a horizontal burning position within 4°. The 1,000 W FCM is the clear lamp used for the chart below. FCM in the FVL lamp lookup.
Strengths and limitations
- Individual heads can follow a curved wall, with each unit aimed along its own section of backing.
- The wash changes substantially with setback. At a 3 ft setback, Mole lists 530 fc at the base and 50 fc at 14 ft. That difference matters when both areas appear in the frame.
Practical uses
Use the Groundrow along the bottom of a painted cyc or behind a translucent backing. Check the wide shot with the set dressed. A low piece of masking may hide the fixture while still allowing light to reach the bottom of the backing.
Output and photometrics
Mole tested an FCM lamp rated 1,000 W, 120 V and 3,200 K. Setback is the horizontal distance from the lamp to the cyc. Reading height is measured up the wall from floor level. Each figure is a foot-candle reading at that position.
| Height on wall | 3 ft setback | 6 ft setback | 8 ft setback |
|---|---|---|---|
| 0 ft | 530 fc | 120 fc | 76 fc |
| 2 ft | 455 fc | 130 fc | 85 fc |
| 4 ft | 345 fc | 115 fc | 78 fc |
| 6 ft | 250 fc | 95 fc | 67 fc |
| 8 ft | 170 fc | 80 fc | 61 fc |
| 10 ft | 115 fc | 74 fc | 56 fc |
| 12 ft | 75 fc | 62 fc | 53 fc |
| 14 ft | 50 fc | 52 fc | 47 fc |
| 16 ft | Unreported | 45 fc | 40 fc |
| 18 ft | Unreported | Unreported | 34 fc |
Exposure from a published cyc setup
Select a measured position on the wall. The camera settings convert that incident reading to an approximate aperture.
Chart reading and exposure
Select a configuration to calculate.
Readings are for the 1,000 W FCM. Meter the backing with the show gel and dimmer level in place. Mole-Richardson Groundrow performance chart.
Power and controls
One 120 V, 1,000 W FCM draws about 8.3 A. The original fixture has a 36-inch three-conductor lead and no onboard switch. Mole also lists 800 W, 240 V lamps for the head. Match both the globe and the fitted plug to the intended supply.
Optics and mounting
The Groundrow rests directly on the floor. Its fixed reflector throws light upward, and the removable front frame carries the gel. A top light can fill the upper part of a tall backing when there is too little floor depth to move the groundrow farther out.
Comparable fixture
The one-cell Molorama Type 2771 can work on floor brackets or overhead hangers. The 3371 has its own floor-standing body. Their light distribution and accessories differ. Compare the Groundrow and Type 2771 in Mole’s rental catalogue.
Field coverage and further reading
Butter Tree Studios’ lighting plan identifies two Type 3371 groundrows in the studio package. B&H also reports the 6 ft FCM test, including the 120 fc floor reading and the 45 fc reading at 16 ft. Butter Tree Studios lighting plan · B&H Groundrow overview.
Rental and used-fixture checks
Check that the front guard and Type 33720 frame seat properly and that the head sits flat. With a row of used fixtures, match the lamp codes before judging the wash. Globes with different wattages or colour temperatures can make a mismatch look like a spacing problem.
Documentation
- Mole-Richardson Type 3371 specifications and performance diagrams (PDF viewer)
- Manufacturer’s Type 3371 specification listing
- B&H Groundrow operating specifications
- Mole-Richardson rental catalogue, Cycs
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