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IR-Pass 685nm

Available in 1.25" & 2"

The Optolong IR-pass filter is designed to boost the contrast in planetary imaging as the infrared radiation is less affected by the atmospheric turbulence (seeing). All planets will appear sharper with the highest possible contrast.

Mercury will reveal its faint details only with an IR-pass filter. This filter is particularly useful for daytime observations as it darkens the background of the daylight.

Venus can show details on its clouds.

Mars shows many more details in the infrared than in visible light, especially during sandstorms which can encircle the entire planet and cover features.

Jupiter appears much more detailed and sharper with the IR-pass filter. Turbulence on the bands, minor vortexes and ultra thin details are only visible at this wavelength.

Saturn offers its maximum sharpness in infrared and in larger apertures, this filter helps to reveal the Encke division.

Uranus and Neptune are distant and without any high contrast details. Only the IR-pass filters can produce interesting pictures.

The human eye is not sensitive to infrared light so this filter is specifically designed for cameras combined with medium or large telescopes.


IR as luminance

CCD & CMOS sensors are capable of detecting light in the infrared range. RGB planetary images taken with IR as the luminance channel have visibly-enhanced contrast and surface detail than standard LRGB images.

Interferential coating

Ion-assisted deposition coating technology for durability and resistance to scratching, as well as stability of the central wavelength.

Multi-coated optics

Fully multi-coated to minimise internal reflections, halos around stars and to assure a high transmission above 95%.

Schott optical glass

1.85mm thick glass made of Schott monolithic optical substrate (non-glued), in ultra-thin, CNC-machined, anodized filter cell.

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