Baader 1.25 inch infrared pass filter blocks wavelengths below 685 nm

Baader IR-Pass Filer HWB 685nm
Reduces the effect of seeing resulting in a much sharper image.
Tip for use: Ideal for imaging and used for the luminosity channel.
The effect of use: The normal spectral bandwidth is 400-700nm. This filter starts at 670nm in the deep red, just in the visual range so it can be focussed correctly. At this long-wavelength spectral range the atmospheric air turbulence (seeing) has much lower impact on the sharpness. Dark structures on Mars, Jupiter the Moon and the Sun are thereby rendered much sharper. The luminosity can then be combined with RGB creating a very sharp LRGB image.

Reflex free anti-reflective and optically polished. At these longer wavelengths, planetary images are less disturbed by wavefront distortions in the atmosphere (seeing). By combining a luminance image taken with the IR-Pass filter, along with RGB frames, overall image sharpness is significantly enhanced. Some of the world's best amateur planetary images have been taken with this technique.

The IR-Pass filter shares the same outstanding features as all the other Baader filters. High optical quality, Striae-free substrate, and high efficiency multicoatings result in the sharpest and highest contrast image possible.