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Astronomik L-2 UV-IR Blocking Filter - 1.25" Round Mounted - L2-1

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SKU: ASF-L2-1

Astronomik UV-IR Blocking Luminance Filters


The Luminance channel is believed to be the most critical aspect of achieving exceptional final image results. In order to gain as much signal as possible, the filter being employed must have a wide spectral bandpass so that it can realize the highest achievable transmission. These two features combine to offer maximum sensitivity while providing the highest photon counts on your pixels. But while a high transmission level is an optimal characteristic of Astronomik's new Luminance filters, some optical instruments, as well as supplemental optical devices such correctors, field flatteners, or reducers, are not perfectly color corrected. This produces problems such as the appearance of soft or bloated stars from incompletely focused light transmission or chromatic aberration. When this happens, image processing can be a challenge. However, with a Luminance filter that has a more narrow spectral window, this detrimental effect can be reduced or even altogether eliminated.

In order to provide users with all the necessary tools to gather the best possible data, Astronomik has bolstered their Luminance filter line. Now you can choose Luminance filter ideally suited for your telescope type to achieve the highest signal and sharpest image for the Luminance channel.

The spectral window size you select for Luminance data will be contingent on your telescope's color correction. The L1 features the widest spectral window, while the L3 has the narrowest. The L2 is roughly the same as the current Astronomik L-Filter.

For optical systems that are totally free of chromatic aberration, the L1 filter is the best option. When working with most optical systems using a corrector, flattener, or reducer in the optical train for common use, the L2 is your choice. Lastly, for users with refractors that feature less than perfect color correction, the L3 filter works best. Also, the L3 can combine with Astronomik's new Deep-Sky RGB filters to lessen the bluish halo effect around stars.

The transmission curve characteristics and coatings on the new Luminance filters have been designed and engineered in such a way that no halos or reflections will be visible. Even with bright stars in the field of view you will be able to reveal the faintest structures in galaxies or nebulae.

Like all Astronomik Filters, the new Luminance filters are made using an extremely durable and scratch resistant coating, deposited on the finest polished optical substrate, which is free of any striae or internal strains. All substrates are made to exactly the same thickness, so all Astronomik filters are parfocal.

Astronomik UV-IR Blocking Luminance Filter Highlights


  • Parfocal with all other Astronomik filters
  • Offers complete resistance to scratching, aging, and high humidity
  • Diffraction limited, this filter will not compromise your telescope's optical performance
  • All Astronomik filters include a durable, high quality plastic filter container