Day-for-night photography is an effect that makes a scene recorded in daylight to appear as if it were at twilight. This is usually accomplished by the use of a filter that both underexposes by about two stops, and can also produce a bluish color overcast. Lighting, contrast, and other factors contribute to the reality of this effect.
Tiffen Day for Night filters are a great way to create the look of night during the day without the hassle. Combined with proper exposure compensation, Tiffen Day for Night filters are an easy and cost effective way to create a realistic dusk or nighttime appearance when filming during the day, simplifying production requirements. These filters will save the expense of what might be extensive lighting needed for large areas when actually shooting at night, instead of making use of available sunlight.
The Cool Day for Night is based on the perception that moonlight is cool, therefore bluish in color. To simulate a feeling of moonlight, a particular shade of lavender is used, producing visual coolness while maintaining realistic flesh tones. In addition, since the ability to see detail at night is diminished at lower light levels, a low contrast component is added to the filter.
The Monochrome Day for Night is based on the fact that low light levels reduce the sensitivity of the eye to color causing a more monochromatic effect. The filter skews the color balance so that upon fine tuning the color timing, the proper monochrome effect can be created. The Tiffen Monochromatic DFN filter is a bright yellow-green, almost the color complement (opposite) of the Cool DFN. When you use this, and perform the necessary color-correction in post processing, you will not have all of the original colors available, producing a more realistic monochromatic effect that simulates actual silvery moonlight. Choice of which one to use is a matter of opinion.
Cool Day for Night and Monochrome Day for Night filters are available in sizes to fit all professional motion picture and video lenses.