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Astronomik L-3 UV-IR Blocking Filter - 42 mm Round - L3-42

SKU: ASF-L3-42

Astronomik UV-IR Blocking Luminance Filters

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 transmission 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 recently expanded their Luminance filter line to provide you with all the tools needed to gather the best possible data. Now you can select the Luminance filter best equipped for your specific telescope system to get the highest signal with the most clear image for Luminance channel.

The color correction of your telescope will determine whether you should use a filter with a wider spectral window for the Luminance data. For the widest spectral window, choose the L1 filter; and for the narrowest spectral window, choose the L3 filter. The middle ground contains the L2 which has about the same size spectral window as Astronomik's current 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 carried by Astronomik
  • Fully resistant to the effects of scratching, aging, and high humidity
  • Diffraction limited, this filter will not reduce the optical performance of your telescope
  • Astronomik filters are delivered with a long-lasting, high quality plastic filter container