The Hoya 77mm Introductory Filter Kit includes a 77mm UV Filter, a 77mm Circular Polarizer Filter, and a 77mm 81A Color Conversion Filter. Each filter in this kit fits a lens with 77mm front filter threads and can provide one of three of the most widely applied enhancements to your imagery. Additionally, these filters are constructed from optical glass within an aluminum-alloy frame, which protect the front element of a lens from scratches, bumps, or impacts. A filter pouch that can accommodate all three filters is included for storage and transport.
The Hoya 77mm UV Filter is a general use, clear filter designed to absorb ultraviolet light and reduce the bluish cast of daylight. Aside from the reduction of unwanted blue casts, no additional coloration or contrast is created, and adjustments to exposure are not required while using this filter. To prevent internal ghosting and reflections while providing approximately 96% light transmission, each glass surface includes one layer of anti-reflection coating.
This UV filter is also useful as a general protective filter to leave on lenses at all times. Such filters help to reduce dust and moisture from reaching your front lens element and provide additional protection in case of drops or situations where scratching could occur.
The Hoya 77mm Circular Polarizer Filter helps to reduce reflections and glare by filtering out light that has become polarized due to reflection from a non-metallic surface. The light from the sun naturally becomes partially polarized due to reflecting off electrons in air molecules, causing the light to scatter into what appears as haze. A polarizing filter arranges, and filters, this directionally polarized light perpendicularly to the reflected light, allowing for the absorption of much of this light. This results in a noticeable reduction of glare and reflections from non-metallic surfaces and an increase in the saturation of skies and foliage.
A circular polarizer only differs from a linear polarizer in that it contains a quarter wave plane in addition to the linear polarizing filter. The addition of this quarter wave plane is to circularly polarize the linearly polarized light for the use of auto focus and exposure functions. Due to how the light is broken down and filtered with a linear polarizer, auto focus and exposure accuracy become skewed during use. When the light becomes circularly polarized, it permits the use of these functions.
This circular polarizer filter is non-coated and has approximately 96% average light transmission.
The Hoya 77mm 81A Color Conversion Filter is designed to provide color correction for tungsten Type B film when used with light sources that are 3,400K. Tungsten Type B film is intended to be used under 3,200K light sources. When tungsten Type B film is used with 3,400K illumination with no filtration, the resulting images will have a blue cast. This filter includes one layer of anti-reflection coating on each glass surface and can also be used with daylight film to provide a general warming effect.
- Hoya 77mm UV Filter
- Absorbs UV light and reduces bluish cast of daylight
- Does not require adjustments to exposure while in use
- Single coated to prevent internal ghosting and reflections while providing approximately 96% light transmission
- Creates no additional coloration or contrast
- General protection filter reduces dust, moisture, and scratches from reaching lens elements
- Hoya 77mm Circular Polarizer Filter
- Helps to reduce reflections and glare by filtering out light that has become polarized due to reflection from a non-metallic surface
- Polarizing filters arrange, and filter, directionally polarized light perpendicularly to the reflected light, allowing for the absorption of much of the light
- Clears up haze in distant landscapes and provides more saturated, vivid colors
- Strongest effect when used at a 90° angle from the sun
- Circular polarizers are ideal for use with digital cameras and autofocus lenses where a linear polarizer will often disrupt auto exposure and focus features
- Approximately 96% average light transmission
- 3 to 4x filter factor reduces exposure by 1.6 to 2 stops
- Hoya 77mm 81A Color Conversion Filter
- Provides color correction for tungsten Type B film when used with 3,400K light sources
- Creates a warming effect when used with daylight-balanced film
- 1.4x filter factor reduces exposure by 0.5 stop
- Single coated to prevent internal ghosting and reflections