Types of Filter Materials
There are three basic variants of materials used in Formatt-Hitech filters:
Firecrest Glass Filters | Resin Filters | Traditional Glass Filters
Firecrest Glass Filters
Firecrest is a multicoating application for glass filters that is by far the most technologically advanced filter manufacturing process on the market. The Firecrest process is a hard-coated electrolytic process that is anti-reflective, scratch-resistant, and hydrophobic. Most importantly, Firecrest technology gives our scientists unprecedented control over modifying specific frequencies of the light spectrum. The result is hyper-neutral NDs, with tailored reductions of ultraviolet, visible spectrum light, near-infrared and infrared. The same technology is used in our new line of Firecrest Polarizers and UV filters.
Firecrest filters are typically built from Schott Superwite or Asahi broadcast glass.
Traditional Glass Filters
Traditional glass filters are those glass filters that we make that don’t require the application of our Firecrest multicoating. These filters include color grads, cinema diffusion, and speciality filters. As most photo filters are now made from Firecrest, traditional glass filters are typically for cinema. Formatt-Hitech glass filters are made from Schott Superwite glass, the finest optical glass material available. The filters effects (such as colors) are applied on advanced, computer controlled manufacturing equipment to ensure consistency of results and accuracy of density. The filters are then lapped and polished to extremely high tolerances to ensure that the surface flatness is the highest in the industry. The surface flatness ensure that waves of distortion aren’t seen when panning the cinema camera.
There is a misconception that glass is better than resin. Formatt-Hitech’s resin filters are ultra flat, have excellent contrast and are completely transparent to the visible light spectrum. In fact, our traditional glass filters are manufactured by sandwiching an optically true resin filter between glass. Formatt-Hitech’s resin has the highest scratch resistance of any non-glass optical material and it’s resistant to most solvents, chemicals, aging and material fatigue. Because of the light weight and portability, resin filters are a great choice for photographers and HDSLR filmakers. Resin filters are dyed using our exclusive Absorbing Cell Technology™ process.
Firecrest ND Test results
These graphs show test results from an independent test performed at The Academy of Motion Picture Arts and Sciences (AMPAS). The test measured the spectral power distribution of tungsten light reflected off a spectralon target made of barium sulfate using a Photo Research SpectraScan Model 705 spectroradiometer. The results were graphed according to their wavelength (in nanometers) along the X axis, versus radiance (in watts per steradian per meter squared) along the Y axis.
In the top graph, the yellow line represents the baseline tungsten light reading reflected off the barium sulfate target. This graph illustrates the excellent filtration properties of both the ProStop IRND (shown in green) and the Firecrest ND (shown in blue). Both filters appear nearly flat from this perspective.
The second graph emphasizes the differences between the two filters by removing the baseline tungsten reading and zooming-in on the Y axis. On closer inspection, the graph shows the ProStop IRND strongly attenuating the near-infrared spectrum before returning to neutral attenuation of the infrared spectrum around the 730nm mark. Firecrest (shown in blue) performs perfectly linearly in the visible light spectrum, before completely eliminating the infrared energy at around the 700nm mark. Compared to the ProStop IRND (which is the previous benchmark in IRND filtrations) the performance shown by Firecrest ND is nothing short of revolutionary. Firecrest ND truly is the future of ND filtration for digital sensors. Results in-the-field confirm the test data. The new Firecrest ND is amazingly neutral regardless of the camera make or model used.