Profi Hard GND Filter
The Rollei Profi Hard GND Filter is a rectangular-shaped grey graduated filter with a hard gradient, suitable for the Pro Filter holder sets from Lee, Nisi, Cokin, Haida and Rollei, of course. A GND filter is an ND Filter that rapidly becomes transparent from the centre outwards with a short transition to the lower end. The upper half of the image is darkened.
In the search for the best optical glass types for the professional Rollei rectangular filters of the next generation a specific, highly transparent product of the German traditional manufacturer, SCHOTT1, was finally selected.A legendary 99 percent of the rays of light that fall on a SCHOTT1 glass are let through and are at your disposal for your photographic ideas.The coating with extremely uniform grey or grey gradient surfaces in the desired intensity is also subjected to a heat treatment at 300 degrees for four hours in order to guarantee the already proverbial strength of the optical glass from the headquarters of SCHOTT AG in Mainz.
The depth of field that has been selected by you for your long-term exposure and/or filter images is reflected by the optical quality of the glass types and the coating. You can fully exploit the resolution of your camera and don’t have to accept sacrifices on the colour spectrum.The super-white and absolutely colour neutral SCHOTT1 glass types are not only used for high-end photo filters. The leading products of the renowned company have also been utilized for many years in the field of scientific documentation.
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.
Hard GDN Filter – Versions and Sizes
Rollei Hard GND Filters are available, depending on the width of the filter holder, in versions GND4 and GND8. The number here illustrates the degree of darkening and the number of f stop reductions.
Hard GND Filters are for filter holders from Rollei, Lee, Nisi, Cokin or Haida with widths of 70 mm, 100 mm, 150 mm and 180 mm and are available in up to two different degrees of darkening, depending on the filter-holder width.
Using Rollei Hard GND Photo Filters
With a Hard GND Filter you have a grey gradient with a hard transition that is to say on a narrow strip in the middle of the filter. This is ideal when the areas are uniformly divided. This prevents over-exposing the sky when photographing a sea horizon. However, it can be used in various ways, so that with the GND filter you can also focus properly on a snow scene without making the evening sky too dark. To do this, you simply invert the filter, for example. Until now, professional photographers have been typically using Hard GND Photo Filters from Lee, Nisi, Cokin or Haida, now Rollei Filters are available, too.
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.