Baader IR-Pass 670nm Filter - 1.25" Round Mounted

Baader IR-Pass 670nm Filter - 1.25" Round Mounted
Item # BA-FIRP-1
  • The Baader IR-Pass Filter blocks wavelengths below 670nm.
  • Planetary images are less disturbed by wavefront distortions at these longer wavelengths.
  • Each Baader Planetarium IR-Pass Filter substrate is fine-optically polished plane parallel for 1/4 wavefront over entire surface.
  • Multi-layer dielectric coatings are plasma-assisted and ionbeam-hardened using the latest technology.
  • Baader Planetarium IR-Pass Filter coatings will never degrade from use or normal cleaning.


Baader IR-Pass 670nm Filter - 1.25"

Baader Planetarium delivers the latest tool in the planetary imager's bag of tricks. The Baader IR-Pass filter blocks wavelengths below 670 nm. 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.

Baader Planetarium IR-Pass 670nm Filter Features

True Optical Quality: Baader glass substrates are of true optical quality. Most other filters are merely made from raw flame-polished, "optically flat", or sometimes a top quality commercially polished filter glass (fine for camera filters), resulting in wavefront deformations that damage image sharpness and contrast when used with telescopes. Baader Planetarium filters are made from striae-free substrates, and actually fine optically polished flat to within 1/4 wave p-v over the entire surface, plane parallel to within 30 seconds of arc! This important and unique custom step adds cost - but the result is a filter that maintains the full wavefront quality of the telescope without double images or ghosting, even at high magnifications. Critical to maintaining this level of flatness are Baader's carefully balanced coating designs, which prevent coating surface stresses from warping the substrate. Such high flatness enables Baader filters to be used far in front of the focal plane, ahead of star diagonals and digital cameras. They are particularly well suited for attachment to the nosepiece of the Maxbright Binocular Viewer (other manufacturer's filters must be used in pairs, attached to the eyepieces).

Filter Durability: Filter durability has always been a hallmark of Baader Planetarium. The multi-layer dielectric coatings are plasma-assisted and Ionbeam-hardened using the latest technology (the coatings are harder than the glass substrate itself!). Baader filters withstand repeated real-world exposure to the elements and physical cleaning. Users need not leave their precious filters dull and dust encrusted to avoid cleaning - Baader filters may be used and cleaned without fear. We have heard sad stories from owners of other simpler soft-coated dielectric filters, who have seen their coatings degrade from normal exposure to moisture, or wiped away from routine cleaning. Some manufacturers even resort to sandwiching their delicate coatings in between two layers of glass (and risking blurred double images as well as eventual degradation from the edges inward). Baader Filters will truly last a lifetime.

Stackability: Unlike other filters, Baader Planetarium filters are truly designed to be stacked and combined. This is possible due to the high optical quality and highly efficient anti-reflection multicoatings. The ability to combine filters opens up many exciting possibilities, permitting unique spectral characteristics unachievable with any single filter.

Special Filter Cell: Baader's special filter cell design offers unique features that enhance their reliability and usability. Though difficult to produce, the ultra-thin filter cell results in the maximum possible clear aperture, in order to minimize vignetting (1.25" Filter clear aperture is 27mm, 2" Filter aperture is 45mm). The special threading has been designed to fit a wide variety of eyepieces and accessories (there is significant variation between the 1.25" filter threading used by eyepiece and accessory manufacturers). The front 'crown' of the filter incorporates milled notches which make handling and threading the filter a more secure operation in the dark.

Low cost: Despite high quality and advanced technology, Baader Planetarium filters are affordable. By leveraging high volumes across all filters in the Baader family, these filters can be offered at very reasonable prices.

Baader Planetarium Product Number: FIRP-1
Additional Information

Additional Information

Manufacturer Baader
Type of Filter IR Pass, Planetary
Filter Usage Imaging
Single or Set? Single Filter
Filter Size 1.25"
Filter Shape Round
Filter Mounted? Mounted
Warranty 1 Year Warranty

Customer Reviews 2 item(s)

Occultation observer
This filter performs exceptionally well for my video recordings of stars occulted by asteroids during twilight hours when normally the video background would be totally washed out. It changes the twilight video sky background to black allowing faint stars to remain visible until near sunrise. Its performance is every bit as advertized and I am happy I added this filter to my collection.
1= Houston, We Have a Problem & 5= It's Out of This World
Review by Tom Campbell / (Posted on 4/18/2012)
Baader IR-Pass Filter Review
Works well as advertized. I see better details in clouds when tested with Jupiter. A comparison between this filter and others is found here:

This filter takes away ALOT of light however so had some difficulty getting sufficient numbers of subs when tested on jupiter due to the need for very high gain and long exposure time compared to a IR block filter
1= Houston, We Have a Problem & 5= It's Out of This World
Review by Fox Keri / (Posted on 8/19/2008)
Included Items

Included Items

  • Baader IR-Pass 670nm Filter - 1.25"
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