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Astronomik L-2 UV-IR Blocking Filter - 42 mm Round - L2-42

SKU: ASF-L2-42

Astronomik UV-IR Blocking Luminance Filters

For spectacular results, the Luminance channel is probably the most vital factor for image creation. To gain the greatest amount of signal possible, the filter being employed needs to have a wide spectral bandpass to realize the highest transmission possible. These two aspects combine to enable peak sensitivity and provide maximum photon counts on your pixels. Not all optical instruments, or supplemental optical elements like correctors, flatteners, or reducers have ideal color correction. So although the high transmission level of these new Astronomik Luminance filters is a terrific feature, the larger spectral band pass width of this filter can produce problems such as soft or bloated stars resulting from excess transmission of light that is not completely focused (chromatic aberration). Image processing can be challenging when this occurs. However, this detrimental effect can be reduced or even completely eradicated by having a Luminance filter with a spectral window that is slightly more narrow.

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.

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.

If your optical system is completely chromatic aberration free, you should get an L1 filter for your setup. For general use with most optical systems employing a corrector, flattener or reducer in the optical train, the L2 is optimal. The L3 filter is made for users with refractors that have less than ideal color correction. Plus, when used in conjunction with Astronomik's new Deep-Sky RGB filters, the L3 filter will reduce that annoying 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 UV-IR Blocking Luminance Filter Highlights

  • Parfocal with all other filters Astronomik produces
  • Provides full protection against the effects of scratching, aging, and high humidity
  • This filter is diffraction limited and therefore will not compromise your telescope's optical performance
  • All Astronomik filters include a long-lasting plastic filter container of superior quality