First of all there are substantial differences between grey filters for filter holder systems and grey filters as screw-on filters. The circular Premium and Extremium ND filters, which are screwed directly onto the lens thread, are substantially lighter and more space-saving in your luggage than our rectangular grey filters for the Mark II plug-in filter system. In addition, they are particularly suitable if you would like to use only one filter. Besides they are more convenient and better suited to beginners. However, professional nature photographers or fans of slow photography increasingly draw upon our Mark II and Rock Solid rectangular filters, as they also have their advantages. So they are to be combined more flexibly, prevent vignetting more effectively and are available in more finely gradated strengths between ND8 and ND2000. Thus, if you want to use several filters at the same time or change them flexibly and fast, the plug-in filter systems are easy to operate.
A special form of grey filters, so-called Grey Graduated Filters, are available from Rollei exclusively as plug-in filters. Grey graduated filters comprise a neutral-grey toning, which doesn’t keep the filter glass in an even neutral grey hue but constitutes a gradient, which runs downward until it is transparent. These are ideal for pictures with high dynamic range, thus many contrasts and different lighting conditions in a subject (sunrises & sunsets, rugged mountain landscapes, the skyline of a large city etc.). Because the incidence of light is not reduced everywhere evenly but is stronger where the subject is also more brightly illuminated and less where poorer lighting conditions prevail. In this way, for example, an overexposed sky with an excessively dark landscape in the foreground at the same time is prevented. In order to be able to adapt the filter to the horizon line of the subject you must be able to shift it back and forth and this is why grey graduated filters are available exclusively as plug-in filters. So if you would like to combine grey graduated and ND filters, then you need a filter holder plus plug-in filters. Also with our plug-in filter systems you don’t have to do without a polarising filter as the latter can be integrated directly into the base ring.
All of our grey filters are high quality, are subjected to several quality control procedures under the most stringent criteria with the smallest tolerances according to the AQL principle and are manufactured from sturdy Gorilla® glass, regardless of whether they are Premium and Extremium screw-on filters, or Mark II and Rock Solid plug-in filters. In addition all of our ND filters guarantee absolute colour neutrality, which we verify regularly in our filter laboratory with our filter machine that was developed in-house. This machine measures the colour spectrum from the UV to the IR range and light transmission at up to 24 measuring points. In the process our grey filters show a uniform curve over the entire colour spectrum, which represents high colour neutrality. In addition the filter glass of our ND filters prevents and suppresses optical distortions and reflections. However, there are also small differences in the different grey filter series, particularly in the coating of the filter glass on the plug-in filters and the socket of the circular filters.
Advantages of the grey filters as Mark II or Rock Solid plug-in filters:
- As soon as the filter holder is installed on the lens, plug-in filters can be combined more dynamically and more flexibly than screw-on filters can.
- Combining up to three plug-in filters + a CPL filter in the base ring (with the 100-mm filter holder) is possible without vignetting.
- The individual filters in the filter holder can be exchanged in a few seconds, in order to be able to react flexibly to changing lighting conditions.
- The combination of a grey filter and a grey graduated filter, e.g. for sunrises and sunsets works more flexibly with filter holder systems (tip: the Mark II Advanced Filter Set consisting of a Mark II 100mm ND1000 Filter, a Mark II 100mm Soft GND8 Filter & a Mark II 100mm Reverse GND8 Filter + a 100mm filter holder)
- Available for 100-mm, 150-mm (wide angle lenses) and a 180mm filter holder (ultra-wide-angle lenses e.g. Sigma 12-24 mm or Canon 11-124 mm)
Advantages of Premium & Extremium grey filters /screw-in filters:
- Grey filters as screw-in filters are compatible with all prevalent lens threads (49 mm, 52 mm, 55 mm, 58 mm, 62 mm, 67 mm, 72 mm, 77 mm & 82 mm)
- Screw-in filters are installed faster than a filter holder but are more difficult to combine
- Screw-in filters are easier and more convenient and therefore particularly suitable for beginners.
- They can be transported without any problem in photo rucksacks & photo bags and are particularly suitable for travel photography and situations where things have to happen quickly (event photography, sport photography etc.)
Differences between Rock Solid & Mark II grey filters for filter holders
The Mark II and Rock Solid ND/GND filters are distinctive due to the coating, thus the multiple-layered coating on both sides of the filter glasses. The Mark II grey filters are equipped with the Luminance Coating exactly like the Premium & Extremium screw-on filters, whereas the Rock Solid Grey Filters have an Unbreakable Coating, which also provides protection against falls from a height of up to 1.20 metres - the typical working height of many stands. Thus you can let Rock Solid ND/GND filters fall between 3 and 10 times without their being damaged. <0} Both Coatings are also impressive due to their absolute colour neutrality and high degree of light transmission and prevent reflections.
Rollei Mark of II, Premium & Extremium grey filters and grey graduated filters with Luminance Coating
The existing Rollei grey filters, which are made from Gorilla®* glass, are additionally enhanced by the Luminance Coating. It prevents the incidental occurrence of reflections, due to procedural specifications during manufacture that were specifically formulated by Rollei, adherence to which is regularly examined by quality assurance in our company, so that you can either use reflections purposefully later or not at all in order to lend your photos an individual look. With the Luminance Coating yet another additional tempering of the excellent filter glass is achieved and mechanical resistance is perceptibly improved whilst retaining freedom from distortion and the greatest possible colour neutrality (colour fidelity). Even the most minor shifts in colour values already at the shooting location have negative effects on all further processing steps.
All Rollei’s grey filters are made from Gorilla® glass
This enhancement rounds out the already very special, durable and weather-proof filter glasses made from Gorilla®* glass additionally without affecting light permeability and colour authenticity. All grey filters from Rollei are made of this particularly resistant, darkened Gorilla®* glass. The glass blanks for the special glass of the traditional American manufacturer from Corning, New York, lie in a hot alkaline solution for an extended period of time, which not only ensures that the glass is extremely weather-resistant but also guarantees that the filter glass itself will withstand the roughest handling. Because the bath in the simmering solution provides for a planned exchange of ions and thus for an enormously increased surface tension, which counteracts scratches and cracks. Excellent light permeability is retained in the process and there are no visual distortions either. The temperature-resistant titanium ring with the Extremium circular filters also ensures that the circular filter can be easily released again from the lens even after challenging outdoor shoots in natural surroundings, in the cold and in bad weather.
As a professional photographer or as a discerning amateur you benefit doubly. You don’t have to worry about possible reflections when you are choosing a location and can fully rely on the impressive weather resistance and robustness of the additionally coated Rollei ND filters made from Gorilla glass®* even in extreme situations. Even bad knocks or unintentional contact with sharp, pointed objects make amazingly little difference to coated and colour neutral filter glass.