Reverse GND Filter
A reverse GND rectangular filter, also known as a grey graduated filter, has the greatest degree of darkening in its centre. The reverse GND filter quickly (concisely) attenuates to transparency from the centre downwards. Upwards, the filter attenuates to light grey.
OOtto Schott, the chemist and inventor from Jena, laid the foundation for SCHOTT AG, a globally operating technology business and a manufacturer of optical products of the highest quality, in 1884.The SCHOTT1 glass types that are used for Rollei’s professional rectangular filters have a transmission value of an astonishing 99 percent. That means that only one percent of light rays is absorbed by the glass material.This is the best pre-requisite in order to be coated with diverse, extremely uniform grey surfaces in the most popular intensities and gradients.However, this coating passes the final quality inspection only after it exhibits no distortions or colour shifts of the slightest kind.
Even in the darkest grey colouring an absolutely sharp image is transmitted to the sensor of your camera by the Rollei professional, rectangular filter that is equipped with SCHOTT1 glass. The creative design options with the desired fuzziness and gradients are exclusively in your hands.Once you have worked with SCHOTT1 glass, you won’t want to scale back your quality standards anymore.
Because of the high-quality processing of the glass, these four quality features of Rollei Photo Filters are guaranteed and set new industry standards among the commonly used ND sets:
- High colour fidelity
- Low reflection
- SCHOTT1 Glass
High colour fidelity for your photos
Rollei Profi Filters have no colour distortion that is perceptible to the naked eye, and Rollei Profi Filters have no colour casts. This has been confirmed in independent testing by Chip magazine and experienced by professional photographers who usually work with filter systems from Lee, Nisi, Cokin or Haida.
Rollei Profi Filters have a (graduated) coating that uniformly lets in light (from ultraviolet almost up to infrared) through the filter. Unlike plastic resin filters and laminated filters, whose colour fades over time and whose bonding can easily come apart, the glass in Rollei Filters is extremely durable and does not fade.
If the light obscuration does not cover the whole spectrum of visible light, colour faults appear. With cameras, the visible light lies between 420 nm ~ 680 nm. The flat spectrum curve means that the light attenuation rate is relatively high and thus less visible light penetrates the filter. If light can penetrate the filter uniformly there are no colour casts. Rollei Filters meet this important requirement.
Reverse GND Filter – Versions and Sizes
A GND8 version of the Rollei Profi Reverse GND Filter von Rollei is available. The number indicates the degree of darkening and the number of f stop reductions, also termed the gradient.
This Reverse GND Filter is available for filter holder sets from Rollei, Lee, Nisi, Cokin and Haida in widths of 70 mm, 100 mm, 150 mm and 180 mm.
Using Reverse GND Filters
A Reverse GND Filter is used for subjects that are very bright at the focal point in the centre. Take, for example, a sunset by the sea where the sun is close to the horizon. The same thing applies with a sunrise of course.
The very bright focal point of the image is darkened using a reverse GND filter. The sun is able to be given full expression, the sky and the water are well exposed, and the contours can be clearly seen. Even with photo processing, you cannot correct when the sun is over-exposed and the image information is lost in the over-exposure. For landscape photographs of professional quality, a reverse GND filter is indispensable and really works wonders. When using filter holder systems from Rollei, Lee, Nisi, Cokin or Haida, you can use one or two Reverse GND Filters at the same time for creative and impressive picture art works.
1 All labelling rights are the property of their legal owners and serve here only for the description and/or the identification of the devices and materials.Schott is a registered trademark of SCHOTT AG.