Antlia IR Pass 685nm planetary filter - 1.25'' Mounted

Article number: IR685-1.25in
Availability: More on the Way to us
Delivery time: More on the Way to Us

The Antlia IR Pass 685nm filter is an absorptive filter that allows infrared

light with wavelengths of more than 685nm to pass through. At these longer

wavelengths, the sensitivity of the unaided eye is reduced, so it is not

suitable for visual observations. The filter is highly recommended for any

planetary photography. At long-wavelength spectral range the atmospheric

air turbulence (seeing) has much lower impact on the sharpness. The

closer to the infrared band, planetary images are less disturbed by

wavefront distortions in the atmosphere (seeing), result in the sharpest and

highest contrast image possible.


By combining a luminance image taken with the IR-Pass filter, along with RGB and U-Venus filters, overall image

sharpness is significantly enhanced and details of planets in different bands are taken.

The filter is also possible to image the other planets during daylight due to the dark background sky created by the 685nm IR Pass Filter.


Technical Data:

Schott optical substrate

1.25” mounted, (2mm+/-0.05mm)

Surface Quality: 60/40 (Refer to MIL-O-13830)

2 sides fine-optically polished to ensure accurate 1/4 wavefront

30 arcsec parallelism


Filter Ring:

1.25”( 28.5*0.6 )

Ultra-thin filter cell to minimize vignetting by maximize possible clear aperture

Black Anodized Finish

Laser Engraving No Fading


Not recommended:

Solar Observing and imaging

Visual observation


Serious eye damage will result if you fail to observe the warning.

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