Vari Con Adjustable Contrast Filter

The Arri VariCon is a compact, variable contrast-con-trol system which quickly and easily slides into the dual filter stage closest to the lens of any regular 6.6"X 6.6" matte box. The VariCon differs from low-contrast filters in that it provides for a continuously adjustable contrast over the entire photometric range of the film without any loss of resolution, and without any effect on the highlights. It differs from standard flashing (pre- or post-exposure) of the negative in the lab or in the film camera magazine in that it adds a controlled, even amount of light during the exposure, and permits the cinematographer to set the desired contrast reduction while observing the results in the viewfinder, in relationship with the actual scene to be photographed. The VariCon also provides for coloring of shadow areas in the image without affecting the highlights. This feature can be very helpful in situations when extreme contrast compression would result in extreme color desa turation.

The system consists of a light source, the VariCon Glass Emitter, the 6.6" X 6.6" VariCon frame that holds the Emitter (with a built-in slot for an ND filter), a digital meter for precise setting of contrast ranges, and a dual-level output Power Supply. With the VariCon placed in the 6.6"X 6.6" stage closest to the lens, it will cover virtually all wide-angle and long focal-length prime lenses, and most zooms. With the VariCon in position and switched OFF, it will not affect image quality or require f-stop compensation.

Adjusting the VariCon

VariCon's contrast-range adjustment is simple: turn a single control knob (located on its left side), or turn a single flexible extension shaft that plugs directly into the VariCon just above the control knob, to adjust contrast up or down. The amount of contrast reduction can be seen through the finder, or be measured via the digital meter for accuracy and repeatability. Set the meter for the camera's f-stop, the film stock's exposure index, and the required contrast range in values xk}/i,1,2,3,4 or 5. (A value of 1 is equal to 20% flashing.) The effective range of VariCon covers situations from F1.4 with 800 ASA to F22 with 100 ASA.

Changing the coloration of the VariCon is done with a gel placed in the VariCon's slide-in gel filter holder. A light sensor built into the VariCon works in conjunction with the meter to compensate for the light reduction of the gel filter. VariCon can also be used in conjunction with other filters to enhance their effects.

NOTE: When using the VariCon, exposing the gray scale/slate with the Varicon switched ON is recommended; it's helpful for the lab timer.

Lens Coverage:

Standard Aspect Ratio: Zoom lenses: 18mm on up Prime lenses: 10mm, 12mm, 16mm on up Super 35 Aspect Ratio:

Zoom lenses: 20mm on up

Prime lenses: 12mm, and 16mm on up

Power Sources:

Varicon has two 50W, 12V 'BRL' Usliio halogen bulbs, powered by 110V AC through a 12V AC adaptor, or from

12V or 24V batteries. (Cables for 24V batteries are available only through special order.)

Power consumption: 96 Watts (8A @ 12V, 4A @ 24V) Dimensions:

Upper light source: 9 X 2 X 1.75 inches Slide-in emitter section: 8 X 6.5 X 0.5 inches Weight: 3 lbs.

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