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

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SKU: ASF-L2-2

Astronomik UV-IR Block L-2 Luminance Filter - 2" Mounted


In order to achieve spectacular final image results, the Luminance channel is probably the most critical element. Therefore the filter being used should feature the highest possible transmision with a wide spectral bandpass in order to gain as much signal as you can. These two factors enable the greatest sensitivity and provide you with the highest photon counts on your pixels. Although the high level of transmission these new Astronomik Luminance filters have is a terrific feature, not all optical instruments (or additional optical elements such as correctors, reducers, and flatteners) can boast ideal color correction. Because of this, a wider spectral band pass can cause problems like the appearance of soft or bloated stars that are the result of insufficiently focused light (chromatic aberration). In such instances, image processing can be a challenge. So having a spectral window that is marginally more narrow can either totally eliminate or at least lessen this damaging effect.

Astronomik has updated their Luminance filter line to include three different spectral window widths so that you can match your L filter to the type of telescope you use. The "L-2" filter is very similar to the classic Astronomik Luminance filter. By contrast, the L-1 has a wider spectral window, while the L-3's spectral window is narrower.

Your telescope's color correction will determine whether you should use a filter with a wider spectral window for the Luminance channel. 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.

The Astronomik L2 UV-IR Block Luminance Filter is great for general use and is well suited to most optical systems with a reducer, corrector, or field flattener in the optical chain. For reference purposes, please note that the L1 Luminance filter is designed to be used with systems that are free from chromatic aberration, and the L3 is designed for use with refractors with some false color because, in combination with the Astronomik RGB filters, it will diminish the bluish halo 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 2" Round L2 UV-IR Block Luminance Filter Highlights


  • Parfocal with any filter from Astronomik
  • Fully resistant to scratching, aging, and high humidity
  • Diffraction limited for no compromise in your telescope system's optical performance!
  • Astronomik filters arrive with a long-lasting plastic storage container of superior quality