Heliopan Variograu Slim ND 0.3 - ND 1.8 Filter - 60mm (ES 60)
Made in: Germany
Exposure: Increase by 1 to 6 Stops
Ambitious or professional photographers will at some stage reach the point where both the setting options of the camera and the spectrum of the film is exhausted. Sometimes the photographer simply wants a longer exposure time than the camera can offer, to achieve a properly exposed image. For example this can be the case if the sensitivity is already set to the lowest possible value, the aperture is completely closed, and a very short exposure time is needed. A gray filter, also known as an ND filter (Neutral Density) extends the exposure time by a certain number of aperture stops. Gray filters by Heliopan are "made in Germany" of Schottglas©. The filters are color and contrast neutral so that the images are not distorted. Gray filters are often used with photographing water. The extended exposure time means that the flow of water in rapids or waterfalls is "softened", without the image becoming overexposed. Heliopan gray filters can be purchased in the following thicknesses: - table of thicknesses and aperture stops. How many time stops (aperture stops) of light the filter absorbs can be seen in the table above.