Spot Meter
Overview
With this patent pending tool you can have two virtual spot light meters to accurately measure relative scene luminance using photometric units (F-stops). For this to work properly you need to make sure that the input image gamma curve is properly configured in the preset settings sidebar. You can move the spot meter probes around the frame and get an accurate exposure value. Middle gray is initially represented by 0 EV at 18% gray, but can be re-calibrated as needed. Other luminance values are represented by the number of stops over or under middle gray. You can also turn on a contrast ratio guide to show the relative lighting ratio between the two probes.
Options
| Option | Values | Default | Description |
|---|---|---|---|
| Meter A | EVs | - | Shows the scene luminance value in relative stops over/under middle gray. |
| Set A | EVs | - | Sets the value of middle gray to whatever meter A is measuring. |
| Meter B | EVs | - | Shows the scene luminance value in relative stops over/under middle gray. |
| Set B | EVs | - | Sets the value of middle gray to whatever meter B is measuring. |
| Contrast | Ratio | - | The luminance contrast ratio between meter A and meter B. |
| Contrast Label | On/Off | On | Controls the visibility of the contrast ratio elastic bar. |
| 0 EV Luma | Real number | 0.18 | The luma value considered middle gray. |
| 0 EV Luma Stepper | - | - | Increment/Decrement the value of middle gray by 0.01. |
| Reset 0 EV | - | - | Resets the value of 0 EV to 0.18. |
Tips
If you want a 2:1 key‑to‑fill ratio, place meter A over a portion of the image that is illuminated by the key light (e.g. the talent’s cheek bone), then drag meter B to the fill side. Adjust lights until the contrast ratio reads 2.0:1.