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 uncoated and has approximately 96% average light transmission.
The Hoya 77mm 81A Color Conversion Filter can be applied to create a warm cast over an entire image. This effect can be obtained under daylight when this filter is used on a film camera system with daylight film installed, or on a digital camera system with its daylight white balance setting selected. This filter's overall coloration corresponds to an ability to reduce 3400K color temperatures to 3200K, which reflects a mired shift value of +18 that can be applied to other starting color temperatures as well. The greater the color temperatures they can potentially reduce to 3200K, light balancing or color conversion filters are considered to be progressively stronger in their effect when used to add warmth to a daylight image.
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
Can add a warming cast to an entire image under daylight when used on a film camera system with daylight film installed, or on a digital camera system with its daylight white balance setting selected
Provides a mired shift value of +18
Reduces 3400K color temperature to 3200K
1.4x filter factor reduces exposure by 0.5 stop
Single coated to prevent internal ghosting and reflections
UV Filter: UV/Haze Circular Polarizing Filter: Circular Polarizer 81A Color Conversion Filter: Color Conversion/Correction Filter
UV Filter: 77 mm Circular Polarizing Filter:77 mm 81A Color Conversion Filter:77 mm
UV Filter: 1 (0 stop) Circular Polarizing Filter: 3 to 4 (1.6 to 2 stops) 81A Color Conversion Filter: 1.4 (0.5 stop)
UV Filter: No Circular Polarizing Filter: No 81A Color Conversion Filter: No
UV Filter: Absorbs UV rays and reduces bluish cast from daylight Circular Polarizing Filter: Eliminates reflections and haze and improves color and tonal saturation 81A Color Conversion Filter: Adds warmth to entire image when used under daylight on a film camera system with daylight film installed, or on a digital camera system with its daylight white balance setting selected