With super light reduction capability, the Aurora PowerND family of fixed neutral density filters is the best light reduction tool for the uncompromising photographer.
The Aurora PowerND family consists of three light reduction ratings:
- ND64 – 6 stops
- ND4000 – 12 stops
- ND65000 – 16 stops
The 6 stop filter is typically used in low light conditions such as sunrise and sunset. Using a 6 stop filter can reduce shutter speed to a few seconds in those conditions.
The 12 stop filter can be used to slow down shutter speed further to minutes in dusk and dawn conditions, or a few seconds during daylight.
The 16 stop filter can do magic during bright daylight, making it possible to expose up to several minutes or more. It can convert a bright day into night, allowing photographers to use two minute exposure time with ISO 100 and f/8 aperture during a bright day.
The ND4000 and ND65000 have distinct advantages in having more stops than the typical ND1000 or ND32000. They allow users to avoid diffraction softening by enabling users to avoid very small aperture settings or alternatively allowing for longer exposures. In the case of the PowerND 4000, that means two more stops than the typical ND1000 and for the PowerND 65000, there’s one additional stop.
The Aurora PowerND family comes with four different formats:
- Circular format for most of the lenses with filter thread sizes from 37mm to 95mm
- Square format of 100 x 100 x 2mm compatible with filter holders from Cokin, Lee, and others
- Aurora CR format for Canon lenses that support rear gel filter
The CR format filter is an industry first rear mount glass format for Canon EF lenses, such as the popular EF 11-24mm F4L USM.
The Aurora PowerND CR format filters are very small and easy to carry. Gorilla Glass is used to provide rigidity and durability for such a small filter.
The CR filters come with a metal filter holder that replaces the original plastic gel filter in the Canon lens. Gel filters are optically inferior with significant deflation of resolution and have a strong color cast.
All PowerND filters use the same multi-layer nano coatings techniques for both light reduction and surface protection. In order to provide accurate color reproduction and high resolution, we apply multi-layer nano-coating to both sides of the PowerND 4000 and PowerND 65000 filters. The end result is that we achieve excellent result in resolution and color rendition.
As avid landscape photographers ourselves, we understand these filters are used in a harsh environment, in places that could be rough, dirty, and wet. Therefore, filters should be able to repel water, oil, dust, and dirt.
Multiple layers of nano-coating technology are applied to glass surfaces. Perfluoropolyethers (PFPE) are used as hydrophobic and oleophobic coating agent. The end result is that water droplets on the surface of the filter can maintain a static contact angle of 110 degrees. Untreated glass can barely maintain 15 degrees. Even a well-known brand’s 10 stop filter keeps less than 40 degrees and their 6 and 15 stop filters do not even have water repel coating.
Independent lab tests show the PowerND filters having very high resolution and color accuracy.
Well known Schott B 270® i Ultra-White Glass is used for the PowerND filters, except the CR format which employs CORNING® GORILLA® GLASS.
In order to minimize vignetting on wide angle lenses, the circular filters (37-82mm) feature a very thin filter profile of 3.4mm (not counting the thread).
The 100mm square filters conform to the industry de facto standard so they can be used in Cokin (Z), LEE 100mm, and other compatible 100mm filter holders. Both the 100mm PowerND 4000 and PowerND 65000 filters have a dense dark foam padding and paint sealing of edges to prevent light leakage during a long exposure.
We are very proud of our Aurora CR format adapter and filters. We take advantage of select Canon wide angle lenses to have a rear mount filter holder and have designed a replacement. The original gel filter holder does not allow glass filters to be used. Gel filters typically have inferior optical characteristics than glass-based ones.
The CR holders are CNC machined with utmost precision. Not only it allows glass filters to be used, but they are also much stronger than the original factory built in plastic holding mechanism.
The reason for using the rear mount filter over the front one is primary the size of filters. Based on results from simulation, if we were to make a front mount filter for the Canon EF 11-24mm F4L USM, a lens that is very popular among the Canon landscape shooters, a filter size would be at least 185mm or larger, either in circular or square format. Filters with such size are not only inconvenient to carry and use, but also expensive.
Our CR filters are slightly larger than a quarter dollar US coin and easily carried around. Just like the rest of the PowerND filter family, the CR filters are coated with the same multi-layer nanocoatings for both light reduction and surface protection against water, oil, dust, and dirt.
Gorilla Glass® is used for the CR filters to provide rigidity and durability for this small size filter.
Canon lenses that can use the CR filters include:
- EF 8-15mm f/4L Fisheye
- EF 11-24mm F4L USM
- EF 14mm f/2.8L USM
- EF 15mm f/2.8 Fisheye
- EF 16-35mm f/2.8L USM
- EF 17-40mm f/4L USM
- PowerND 64 (ND 1.8) – 6 stops
- PowerND 4000 (ND 3.6) – 12 stops
- PowerND 65000 (ND 4.8) – 16 stops
- Φ37mm, Φ39mm, Φ40.5mm, Φ43mm, Φ46mm, Φ52mm, Φ55mm, Φ58mm, Φ62mm, Φ67mm, Φ72mm, Φ77mm, Φ82mm, and Φ95mm
- Φ150mm with Nikon AF-S 14-24mm f/2.8G adapter
- 100 x 100 x 2mm compatible with Cokin Z, LEE and other 100mm filter holders
- Aurora CR format for Canon EF 11-24 F4L USM with adapter replacement