ND Filter - Rollei Premium ND8 Filter ND filters, such as this 49mm ND8 filter, are no longer used solely by nature and landscape photographers to extend exposure times – a technique useful, for example, for removing people and cars from the foreground when taking architectural shots in busy city centres. As a moderate neutral density filter, the Rollei Premium ND8 circular filter extends the possible exposure time by three stops and provides a good basis for a variety of photographic ideas. Gorilla®* glass protects the ND8 filter from rough handling The Rollei PremiumND8 filter is made from the particularly durable Gorilla® glass supplied by the American manufacturer Corning Inc. The glass blanks are exposed to an extremely hot alkaline solution, which causes an ion exchange at the molecular level. The surface tension of the glass is increased, making it resistant to mechanical impact, weathering and pressure. Even if the glass surface is damaged, there is no risk of further chipping, and the scratch will not spread. Quality control to exacting standards Following a further special treatment of the filter glass – the proprietary Luminance Coating – the filter surface features a kind of ‘protective shield’ against oil, water and dirt, and gains enormous resistance to mechanical stress thanks to the final anti-scratch layer. The Luminance Coating ensures high light transmission and outstanding colour neutrality, whilst also effectively preventing distortions and reflections. These are ideal conditions for preserving the optical characteristics of the original subject in their purest form. To guarantee these unique optical and material properties, Rollei has introduced a particularly stringent quality management system. Rollei Premium ND8 round filters have been meticulously checked several times; even during the development phase, Rollei’s filter experts precisely defined every subsequent production step. The Premium ND8 filter is available in the nine most common lens diameters, ranging from 49 to 82 mm.