ND Filter (neutral-density filter)
The Rollei Profi ND Filter is a rectangular-shaped, professional, neutral-density filter, suitable for the Pro Filter holder sets from Lee, Nisi, Cokin, Haida and Rollei, of course. The abbreviation ND stands for Neutral Density, which refers to light density. In colloquial speech, we also talk about “swallowing light”, since the ND filter also reduces the amount of incoming light. This produces a uniform darkening, which also explains the alternative name, “grey filter”.
Rollei’s high-end rectangular filters are manufactured from genuine SCHOTT1 glass.This glass from the traditional company that was founded in Jena in 1884 combines unusual optical characteristics:The transmission value is 99 percent and only one percent of the light is absorbed by the extremely transparent material. These are ideal preconditions for the subsequent coating with absolutely neutral grey or grey gradient surfaces.SCHOTT1 glass spends four hours in the heat chamber at an uncomfortable temperature of 300 degrees Celsius and it is only then that the coating meets the incredibly strict quality standards of the globally operating glass specialists.
After this special treatment, Rollei rectangular filters made from SCHOTT1 glass are also resistant to the roughest treatment and the most adverse environmental conditions.Careful and absolutely uniform evaporation on highly transparent and colour neutral glass guarantees you absolutely sharp results without any loss of quality even if exposure times are extremely long.You decide on the light composition for your creative picture ideas. Therefore, Rollei rectangular filters made of SCHOTT1 glass ensure that you always have a maximum amount of it at your disposal.
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
ND Filter Strengths
The Rollei ND Filter is available in five different strengths. The ND8 Rectangular Filter has three Stops, as they are called, which means that the amount of light is reduced by three aperture stops, which in turn means that the exposure duration/shutter time increases eight-fold. With the ND1000 the amount of incoming light is reduced 10 aperture stops. Thus with ND filters the duration of exposure does not behave linearly but rather logarithmically.
The full range of strengths for the Rollei ND Filter is as follows ND8 (3 stops), ND64 (6 stops), ND512 (9 stops), ND1000 (10 stops), ND2000 (11 stops). This selection of strengths was developed by Rollei engineers in close collaboration with experienced filter photographers, taking into consideration both the competition and usability analyses.
Time exposure with ND filters
Many situations arise where it makes sense to use an ND filter, for example, with fluid movements that the human eye cannot perceive as such in an image. Newer cameras in particular are often extremely light-sensitive, which makes working with long shutter times a challenge. ND filters prevent over-exposure of your photos.
Patches of mist, rivers, waves, lakes, passing clouds – all of these are typical situations in which you can or should work with ND filters. Such fluid motion is captured by the long shutter time and at the same time light is “swallowed up” by the grey filter to create a soft and smooth image in which the motion is still able to be perceived.
ND photo filters in various sizes for different systems
ND filters are available for filter-holder sets from Rollei, Lee, Nisi, Cokin and Haida in widths of 70 mm, 100 mm, 150 mm and 180 mm. Filter sizes 150 mm and 180 mm correspond to individual lenses, while sizes 70 mm und 100 mm can be used more universally for different filter systems.
For what lenses and holders are they suitable?
These Rollei Pro Filters are fully compatible with holders from Lee, Nisi, Cokin and Haida, all of the filters made by these manufacturers also fit perfectly into the Rollei Pro Filter holders. The Rollei product philosophy is to always provide maximum flexibility to photographers.
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.