LC-Tec Creates World’s First Electronic Variable Diffusion Filter

A dark background with two sets of candle holders. On the left, seven candles are lit in descending order from the center. An orange arrow points to the right, where all ten candles are brightly lit in a similar descending order from the center.

Swedish company LC-Tec specializes in liquid-crystal optical technologies, including optical shutters and variable neutral density filters. Its latest innovation is the world’s first — an Electronic Variable Diffusion (EVD) filter system for cinema lenses.

Showcased at the ongoing IBC Expo in Amsterdam, LC-Tec’s EVD is designed to be mounted in a matte box and offers user-controlled, continuously variable diffusion. The current EVD prototype comprises a 4 x 5.65-inch glass filter and a small connected controller box. During shooting, the cinematographer can smoothly vary diffusion strength for the desired creative effect.

A triptych showing the gradual change in a fluorescent yellow-green sign that reads "Electronic diffusion" from blurry on the left to sharper in the center and right image. Below the sign are rows of color swatches and a color calibration chart.
From left to right: zero volts, three volts, and five volts.

“Cinematographers will also be able to vary the diffusion strength during a shot for creative effect, something that was practically impossible until now with modern cinema equipment,” LC-Tec explains. “It will also theoretically be possible to adjust the diffusion intensity as focal lengths are changed whilst zooming. There is also the possibility for remote operation where diffusion can be adjusted while the camera is in a hard-to-access location like on a jib or crane.”

Precise changes in voltage control the diffusion effect by dynamically changing the physical properties of the filter. For example, with a five-volt charge applied to the filter, the diffusion effect is much stronger than with a three-volt charge.

This alone is a breakthrough innovation in diffusion technology, which has thus far been limited to static diffusion amounts through a typical filter. However, LC-Tec says the EVD goes beyond that. It is possible for electronic diffusion to be applied at different strengths to localized parts of the filter.

A menorah with seven lit candles glowing brightly in the darkness. The candles are arranged in a row atop a candelabrum, casting a warm, golden light against a pitch-black background.
Zero-volt charge applied
A dark background highlights seven lit candles arranged in a candelabra, each flame glowing warmly and casting a soft light. The candelabra's base is partially visible, rising from the bottom of the image. The scene evokes a sense of calm and serenity.
2.5-volt charge applied
A dark room illuminated by the warm glow of seven lit candles arranged in a candelabrum. The flickering flames cast a soft light against the darkness, creating a serene and tranquil atmosphere. Only the silhouettes of surrounding objects are faintly visible.
Three-volt charge applied
A group of seven lit candles arranged in a candelabrum in a dark setting. The candles emit a warm, flickering light that illuminates their immediate surroundings while the background remains pitch black.
Four-volt charge applied
Dimly lit chandelier with seven glowing candles against a dark background, creating a warm and moody atmosphere. The candles are arranged in a symmetrical pattern, casting a soft, yellowish light.
Five-volt charge applied

“For example this localised diffusion could be used to bloom light sources without affecting the skin detail or subject,” LC-Tec explains, “or conversely to soften skin detail white retaining the overall characteristics of the rest of the frame.”

The company says that traditional diffusion filters have required a lot of guesswork from cinematographers, as different lenses, T-stops, scenes, subjects, and lighting conditions all impact how a diffusion filter affects the look of the shot. The same filter may bloom a light source differently on one lens than another or affect global contrast to varying extents. If a cinematographer can adjust the strength of the filter on the fly without changing filters, it is a total game changer.

LC-Tec is no stranger to using voltage to adjust the intensity of a filter effect, as the company has long manufactured electronically variable ND filters. The company’s PolarView-eND is used in numerous cinema cameras on the market. LC-Tec is taking a similar approach with its new EVD, which will be available to third-party manufacturers in Q2 2025. The precise form factor will depend upon a manufacturer’s specifications.

For those attending IBC, LC-Tec is showing its new EVD technology at booth 12.A42.


Image credits: LC-Tec

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