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Astronomik - Planet IR Pro 742 Filter - 1.25" Round Mounted


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Manufactured by: Astronomik


ASTRONOMIK - ProPlanet 742 IR Filter -  1.25"  (Mounted)

The Astronomik ProPlanet 742 is the ideal filter for highly detailed inspection of the moon and planets with telescopes of 6" (150mm) aperture.and greater.

The ProPlanet 742 IR only allows infrared light with wavelengths of more than 742 nm to pass.  In this wavelength range the negative results of  "seeing" are significantly lower than in the visible spectrum of the human eye. This allows much sharper images than are usually obtained from your telescope and location. Another advantage is that the sky background of advanced dawn is dark and so the filter even allows photography of the planets and the moon at daylight.

The Astronomik ProPlanet 742 cuts off the visible part of the spectrum and allows the light of wavelengths longer then 742nm to pass.  Due to this, the part of the spectrum that is most sensitive to "bad seeing" is rejected. This results in vastly improved  imaging of planets and our moon. The image is more steady than the image in visible light with nearly identical exposure times.

Besides astrophotography, the filter allows you to get stunning results in nature photography.  If an EOS-Clip Filter is used in an MC modified DSLR you get tremendous results imaging flora and fauna. The filter cuts off the part of the spectrum where chlorophyll looks green and shows its high reflectivety in the near infrared. If trees are photographed in spring and summer under blue skies you get stunning images with white trees and clouds in front of a near black backgrounds. The Astronomik ProPlanet 742 darkens the background during twilight and allows imaging of bright planets, stars and comets by day. It also promotes imaging of young stars in dust clouds and stellar nurseries. When the seeing is very bad and the instrument is 10" (250 mm) or larger, the Astronomik ProPlanet 807 may be the better choice.

Astronomik 1.25" ProPlanet 742 IR Filter - Features:

  • More then 96% transmission for wavelengths of 742nm to 1100nm
  • Blocking of wavelengths between 350nm and 730nm
  • Parfocal with other Astronomik filters
  • Glass thickness: 1mm
  • Completely resistant against high humidity, scratches and aging effects
  • Diffraction limited, the filter will not reduce the optical performance of your telescope
  • Astronomik filters are delivered in a high-quality filter box





Product Series

These new filters serve particularly the needs of the digital photographer imaging the solar system with electronic cameras or Webcams (with IR-block filter removed) at long-focus telescopes.

The Astronomik planet IR pro CCD filter offers two main advantages: 1. The filter passes only light within a range, that makes seeing become much lesser apparent than in the visual. In other words: The picture becomes substantially steadier and thus also sharper in large telescopes. 2. The filter is particularly useful for Mars CCD photography, because it opens at wavelengths, in which the surface details show the highest contrast. Further advantages to the well-known RG filters from Schott: * better suppression of seeing as with Schott RG 665 * steeper flanks (shorter exposure times) * multi-coated surface (better contrast) * optical thickness identically to other Astronomik filters (parfocal) * transmission adjusted for perfect use with amateur telescopes Why two different kinds of filters? Solving the problem of decreasing optical resolution at higher Wavelengths was the main goal of the Astronomik team. So you are able to make use of the better imaging quality caused by lower seeing effects. Besides this the nearly unpredictable near IR sensitivity of most CCD and CMOS Sensors gave this issue a higher complexity. Using the results of a number of different tests made by the team, confirmed by amateur experiences throughout the country, an optimal filter transmission curve could be determined. The 742 filter is designed for telescopes of smaller diameter. At this wavelengths most electronic cameras have still almost their full efficiency. The majority of wavelengths troubled by seeing effects, is blocked. The 807 filter is perfect for telescopes starting at 8 inch diameter. At this wavelengths most electronic cameras are less sensitive. This effect is compensated by the larger aperture. But here however the seeing becomes much lesser apparent than with the shorter-wave passing filter. Facts: Main application For planetary and lunar photography these filters block the whole visual light. The pass the near IR where the seeing is much better than at visual wavelengths. You'll get better images. Especially for mars these filters enhance the part of the spectrum where dark and bright details have maximum contrast. visual observation not useful classical photography not useful CCD-photography The filter is optimized for telescopes with more than 5 inch (~12,5cm) diameter. Use it with a webcam or video camera without a IR-blocker ! The focal ratio for optimum results is f/25 .... f/40 Main parameters Transmission up to 98 % Blocking at 400 - 720 nm Transmission >95 % above 760nm * Transmission of more than 98% in the near IR * Extreme steep flank at 742nm * completely resistant against high humidity and scratches * highest optical quality on the market

Additional Information

Name Astronomik - Planet IR Pro 742 Filter - 1.25" Round Mounted
Manufacturer Astronomik
Model P742-1