The Hoya 25mm Introductory Filter Kit includes a 25mm UV Filter, a 25mm Circular Polariser Filter, and a 25mm 81A Colour Conversion Filter. Each filter in this kit fits a lens with 25mm 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 aluminium-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 25mm 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 colouration 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 25mm Circular Polariser Filter helps to reduce reflections and glare by filtering out light that has become polarised due to reflection from a non-metallic surface. The light from the sun naturally becomes partially polarised due to reflecting off electrons in air molecules, causing the light to scatter into what appears as haze. A polarising filter arranges, and filters, this directionally polarised 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 polariser only differs from a linear polariser in that it contains a quarter wave plane in addition to the linear polarising filter. The addition of this quarter wave plane is to circularly polarise the linearly polarised light for the use of auto focus and exposure functions. Due to how the light is broken down and filtered with a linear polariser, auto focus and exposure accuracy become skewed during use. When the light becomes circularly polarised, it permits the use of these functions.
This circular polariser filter is non-coated and has approximately 96% average light transmission.
The Hoya 25mm 81A Colour Conversion Filter is designed to provide colour 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 25mm 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 colouration or contrast
- General protection filter reduces dust, moisture, and scratches from reaching lens elements
Hoya 25mm Circular Polariser Filter
- Helps to reduce reflections and glare by filtering out light that has become polarised due to reflection from a non-metallic surface
- Polarising filters arrange, and filter, directionally polarised 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 colours
- Strongest effect when used at a 90° angle from the sun
- Circular polarisers are ideal for use with digital cameras and autofocus lenses where a linear polariser 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 25mm 81A Colour Conversion Filter
- Provides colour 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
|Type||UV Filter: UV/Haze |
Circular Polarising Filter: Circular Polariser
81A Colour Conversion Filter: Colour Conversion/Correction Filter
|Size||UV Filter: 25 mm |
Circular Polarising Filter:25 mm
81A Colour Conversion Filter:25 mm
|Filter Factor||UV Filter: 1 (0 stop) |
Circular Polarising Filter: 3 to 4 (1.6 to 2 stops)
81A Colour Conversion Filter: 1.4 (0.5 stop)
|Multi-Coated||UV Filter: No |
Circular Polarising Filter: No
81A Colour Conversion Filter: No
|Effect||UV Filter: Absorbs UV rays and reduces bluish cast from daylight |
Circular Polarising Filter: Eliminates reflections and haze and improves colour and tonal saturation
81A Colour Conversion Filter: Corrects for 3,400K light sources when used with tungsten Type B film
|Front Filter Thread Size||25 mm|
|Front Lens Cap Size||25 mm|