Professional Soft GND Filter Mark II
The Rollei Pro Square Filter Mark II with Soft Graduated Neutral Density is a rectangular, grey graduated filter with a soft gradient, suitable for the Pro Filter holder sets from Lee, Nisi, Cokin, Haida and Rollei, of course. A GND filter is an expanded ND Filter that attenuates to transparency towards the lower end. The upper half of the filter begins darkened and, attenuating smoothly, decreases in darkness as it flows downwards.
High colour fidelity for your photos
Rollei Profi Filters Mark II 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 Mark II 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.
Soft GND Filter with various gradients
The Rollei Soft GND Mark II Filter is available, depending on the filter-holder width, as versions GND4, GND8, GND16 and GND32. The number illustrates the degree of darkening and the number of f stop reductions.
Rollei Soft GND Mark II with Gorilla®* Glass
Photo filters are usually used for outdoor shoots and are some of the most important aids of photographers, who deal intensively with long-term exposures. Accordingly LP and GND filters must be weather-proof, translucent, colour neutral and insensitive to impacts and contact with sharp edged or pointed objects. Gorilla®* Glass from the American traditional manufacturer, Corning Inc., exhibits these (actually self-contradictory) characteristics and is being used with immediate effect for Rollei’s high-quality professional rectangular filters.
Being fully dipped in an extremely hot alkaline solution provides for the already legendary resistance of the glass blanks: ions are exchanged on the molecular level. Due to the resulting increase in surface tension Rollei rectangular filters of the professional class already take the punishment of contamination, scratches and ruptures in an outstanding way. Even more profound damage causes no further splintering of the material on the edges. Additionally, a further coating, which was developed in accordance with Rollei’s strict specifications and is constantly tested for quality, guarantees the extensive elimination of undesired reflections and distortions, which can lead to nasty surprises during long-term exposures.
The American manufacturer from Corning, New York also looks back on a more than 160- year success story in the development and manufacture of special kinds of glass for lenses, displays and special applications and supplies its products also to renowned companies in the Smartphone and Tablet segment. The Gorilla®* Glass of the newest Rollei rectangular filter generation are only 2-mm thick. You can use all the optical advantages, without having to drag unnecessary weight around during your photography trips.
Rollei Soft GND Mark II with Luminance Coating
Creative work with light reflections is its own discipline in the broad portfolio of photography techniques. What is added (completely consciously) is so playful on the one hand and on the other hand, can lead to substantial frustration if unintentional reflections and distortions completely ruin or substantially impair laboriously prepared and/or unique subject scenarios. Even whilst working with photo filters and long-term exposures minimal, undiscovered reflections can be enhanced to a considerable extent by the extension of the exposure time. Then quite often photographers are forced to change their shooting position and to make do with less spectacular perspectives.
The coating, which was newly developed and is constantly examined by Rollei counteracts these unpleasant effects. Due to the additional coating, the already extremely high-quality Gorilla®* Glass from the special manufacturer, Corning Inc., which is resident in the US Federal State of New York, is able to unite three special characteristic fields in itself which are actually in opposition to each other:
- Extreme resistance to weather conditions, contamination due to dust, sand, liquids, fats or oils as well as damage, scratches, pressure effects and ruptures.
- Protection against light reflections and optical distortions.
- Outstanding optical values within the ranges of light transmission and colour neutrality.
For example, the kinds of glass of the Rollei professional rectangular filters must behave so neutrally in the visible range of light from 400 to 800nm that even merely minimal colour deviations cannot impair image quality at any time.
A particularly stringent quality assurance strategy introduced by Rollei provides for adherence to these standards.
Engineered and Quality Controlled in Germany
Rollei professional rectangular filters combine optical and outstanding technical and material characteristics, which can be durably guaranteed only by appropriately high, uncompromising quality standards. If one of the characteristics should be impaired by quality defects, this would also have negative effects on the other areas. Rollei developed and implemented its own quality management strategy to secure these strict specifications seamlessly: The measure named Engineered and Quality Controlled in Germany includes all phases of development up to delivery to the customer.
In the process, accurate flow charts are used to ensure that quality criteria cannot be retrogressively relaxed at any time. The specifications are created by the Rollei filter experts and cannot be reduced or changed in the further steps. The release of new production samples for mass production lies in the hands of our experienced specialists.
After actual production the AQL principle is in effect for the particularly unyielding test runs. "Acceptance Quality Limit is known as "Annehmbare Qualitätsgrenzlage" in German and has the following meaning in concrete terms: If the total number of the previously, precisely defined quantity of random samples from a production batch do not adhere to the quality specifications, the entire supply will be rejected and must go back to the manufacturer. However, if the production batch has passed this examination, an AQL procedure is repeated after it is sent to Rollei. This extraordinarily stringent procedure is used only for extremely high-quality products and is thus also outstandingly suitable for Rollei professional rectangular filters.