UV/IR Blocking Filter

09 Dec 2013

UV/IR Blocking Filteruv-logo

 

HR Digital UV/IR

 

uv-lensDigital camera sensors are also somewhat sensitive to ultra iolet radiation (UV) and to a high degree to infrared radiation (IR). A corresponding blocking filter in front of the sensor is therefore required for correct-color digital shots. It also serves as a protection for the microlens elements and the RGB Bayer filter (chessboard-like array of tiny red, green and blue filters which allocates one of the three RGB colors to each pixel).

Its blocking effect is unfortunately not sufficient for some digital cameras and specifically not for  older digital cameras. This means that with a high infrared portion in the light chlorophyll can appear too bright because it is highly reflective for IR radiation.

Furthermore, false colors then arise because not only the red color, but also the green and blue colors of the RGB Bayer filter are transmissible for infrared. A reddish tinge, such as is initially expected, therefore does not always have to occur. Whether only a brightening occurs or also false colors and the strength of the two features depend on the efficiency of the camera’s internal IR blocking filter and on the IR transmissibility of the individual RGB filters.

Furthermore, if the IR transmissibility is too high, blur can also occur because the lens is not corrected for IR.

Using the Rodenstock UV/IR blocking filters means that you are always on the safe side both for a far view with a high portion of UV radiation (see pages 8 and 9 for more details) and in intensive sunshine with a high degree of IR reflection by chlorophyll. It blocks UV and IR radiation with a steep flank and ensures true colors.

Cameras with a sensor modified for infrared shots or astronomical H-alpha shots always require an external UV/IR blocking filter for use for normal true-color shots.

The UV/IR blocking filter does not require any exposure correction.

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Water absorbs infrared radiation. Therefore, the reflections of the trees on the water keep green even without a UV/IR blocking filter.

HR Digital UV/IR.

Best optical glass · perfect optical surface quality · color neutral · steep-edged interference filter · very scratch resistant · rugged slim brass ring with front thread · wide-angle compatible

Sizes: 37 / 39 / 40,5 / 43 / 46 / 49 / 52 / 55 / 58 / 62 / 67 / 72 / 77 / 82 mm

 

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