Cinematographer
1/2 CTO is my go-to filter for simulating golden hour with HMIs. An M18 through a window with 1/2 CTO creates a warm sunlight look.
Mid-strength CTO color correction filter with -68 Mired shift for warming daylight (5600K) to 4100K.
Technical Specifications
1/2 CTO (Color Temperature Orange) shifts the color temperature by -68 Mired, lowering daylight from 5600K to approximately 4100K. Lee Filters lists this filter as #205 ("Half C.T. Orange"), Rosco as #3411. Light transmission is 55%, corresponding to a loss of 0.9 stops.
Window Application
The most common application for 1/2 CTO is large-scale filtering of daylight through windows. On location shoots, unfiltered window light (5600K) creates a strong cool-warm contrast with tungsten light in the room. With 1/2 CTO, this contrast is reduced to an acceptable level.
Workflow with HMI Lights
For exterior fill light, 1/2 CTO is used to simulate golden hour light. An M40 HMI through 1/2 CTO delivers 4100K light, which appears warm and flattering on skin tones.
Comparison of CTO Strengths
| Filter | Mired Shift | Kelvin (from 5600K) | Light Loss |
|---|---|---|---|
| 1/8 CTO | -17 | 5300K | 0.2 Stops |
| 1/4 CTO | -34 | 4900K | 0.5 Stops |
| 1/2 CTO | -68 | 4100K | 0.9 Stops |
| Full CTO | -131 | 3200K | 1.3 Stops |
From the crafts
Perspectives
Director
I use 1/2 CTO for emotional transitions. The shift from cool to warm subconsciously signals a change in mood to the audience.
Producer
A 1/2 CTO on the window surfaces reduces the need for separate tungsten units. The filter costs pay for themselves after one shooting day.
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Quiz
1. Zu welchem Department gehört „1/2 CTO (Half Orange)"?
2. Wie viele verschiedene Fachperspektiven bietet dieser Eintrag?