How UV-IR Filters Work

What It Does

Get More Accurate Visible Color With UV-IR Cut Filter
hoya nxt uv filter hoya nxt uv filter

The Hoya UV – IR Cut is designed to be used with cameras that do not have an IR filter in front of the imaging sensor. This specialized filter has the ability to cut both UV rays below 390nm and IR rays above 700mn leaving just the light rays in the visible spectrum passing through the filter and into the camera.

This is important because unfiltered CCD and CMOS sensors are extremely susceptible to UV and IR rays just outside the visible spectrum. These rays can cause light contamination and have a very negative impact on image quality. This filter is used on a digital cameras and cine cameras that do not have an IR protection filter or cameras that were modified to have the sensor removed.

How It Works

The effect of the filter is achieved mainly through the multi-layer coatings on the surface of the filter. Hoya begins with crystal clear, colorless optical glass and then bonds coating to this filter that block both UV and IR light rays outside of the range mentioned.
There is light incidence angle dependence in the transmission factor because over-layer is thick, so this filter isn’t suited for wide-angle lens. However it is suited for astrophotography with standard and telephoto lenses.

PLEASE NOTE: The UV-IR CUT filter is intended for use with digital SLR cameras and cine cameras that do NOT have an IR filter installed in front of the sensor. Color balance effects can occur when this filter is used with cameras that have an IR filter installed in front of the sensor. Please consult your camera’s owner’s manual before use.

The Hoya UV & IR light transmission curve shows the sharp-cut nature of the filter glass and coatings as well as the consistent light transmission in the visible spectrum. This curve demonstrates an even more visible light transmission than the closest competitor. This means that sharper images with more depth and finer, richer color gradations are possible with the Hoya UV & IR Cut filter.

AN IMPORTANT NOTE REGARDING WIDE-ANGLE LENSES:

Increasing the angle of incidence, meaning light rays entering the filter from an extreme angle as is the case with super-wide and ultra-wide angle lenses, leads to an increasing color shift as the angle increases. This is based on the physics of light and the nature of the coatings. All UV-IR cut filters have the same properties in this regard. It is not recommended that this filter be used with lenses having a field of view greater than 60 degrees.

The Hoya UV & IR Cut filter is available in sizes 49mm through 82mm.