| Type |
Reflex-viewing spot-reading automatic/manual luminance meter |
| Measuring method |
Reflected light by silicon photo cell with 1° angle of acceptance |
| Viewing System |
Focusing through-the-lens reflex type |
| Objective lens |
85 mmf / 2.9 |
| Angle of view |
Circular 9° with central 1° marked circle |
| Magnification |
2.96X focused at infinity |
| Focusing |
1m (3.3 ft.) to infinity by objective single helicoid; eyepiece adjustable from 4.6 to ±2.7 diopters |
| Minimum measuring area |
ø15 mm at 1m (ø2.4 mm with close-up lenses) |
| Response time |
Automatic: |
Approx. 3 sec. from 0.01 to 99900 |
| Manual: |
Approx. 2 sec. from 001 to 999 |
| Analog: |
90% within 0.4 sec. |
| Calibration |
C.I.E. standard |
| Spectral-sensitivity error |
Within ±2% or C.I.E. relative photopic luminosity curve |
| Accuracy |
Within ±4% of C.I.E. standard, ±1 digit in last display position |
| Screen-flicker accuracy |
within 1% of average luminance with projection cycle of more than 72 Hz and a duty of 70% (projector at 24 fps) |
| Influence of flare |
Less than 1.5% from outside the 1°angle of acceptance |
| Analog output |
Output voltage: 1v over full scale |
| Output impedance |
10 k ohms |