CTO, CTB and green gels in one chart
CTO warms a light by adding mired and CTB cools it by taking mired away. LEE's Full CTO adds 159 and Rosco's 167; LEE's Full CTB takes 137 and Rosco's 131. Here is every sheet in both books, with what it does to a 3200 K lamp and to 5600 K daylight.
| Sheet | LEE | Mired | On 3200 K | On 5600 K | Rosco | Mired | On 3200 K | On 5600 K |
|---|---|---|---|---|---|---|---|---|
| 1/8 CTO | LEE 223 | +26 | 2950 K | 4890 K | R3410 | +20 | 3010 K | 5040 K |
| 1/4 CTO | LEE 206 | +64 | 2660 K | 4120 K | R3409 | +42 | 2820 K | 4530 K |
| 1/2 CTO | LEE 205 | +109 | 2370 K | 3480 K | R3408 | +81 | 2540 K | 3850 K |
| Full CTO | LEE 204 | +159 | 2120 K | 2960 K | R3407 | +167 | 2090 K | 2890 K |
| 1/8 CTB | LEE 218 | −18 | 3400 K | 6230 K | R3216 | −12 | 3330 K | 6000 K |
| 1/4 CTB | LEE 203 | −35 | 3600 K | 6970 K | R3208 | −30 | 3540 K | 6730 K |
| 1/2 CTB | LEE 202 | −78 | 4260 K | 9940 K | R3204 | −68 | 4090 K | 9040 K |
| Full CTB | LEE 201 | −137 | 5700 K | 24050 K | R3202 | −131 | 5510 K | 21020 K |
Published mired shifts, as Cutvey Meter carries them. The same name can differ by up to about 28 mired between the two books (a half CTO is +109 from LEE and +81 from Rosco), so the app works the answer out in the book you pick. Download the CSV (CC BY 4.0).
Plus and minus green
| Strength | Plus green | Minus green | Nominal |
|---|---|---|---|
| Full | LEE 244 | LEE 247 | CC 30 |
| Half | LEE 245 | LEE 248 | CC 15 |
| Quarter | LEE 246 | LEE 249 | CC 7.5 |
Nominal CC values. Tubes and LEDs vary lamp to lamp, so test a sheet on camera before you gel a whole floor. The app's plus or minus green suggestion is marked approximate.
In the app
The gel, named while you point at the light.
Pin one light, point at the next, and Meter names the sheets in LEE numbers, Rosco numbers or both.
Get Cutvey Meter