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IMPORTANT: Our store is located in Canada. All orders that include products manufactured outside of Canada or USA will be subject to tariffs and duties, regardless of the order value. US customers are responsible for all applicable duties and tariffs, and those will be billed by the carrier, except for the Lacerta upgrade kit, for which we collect them at checkout.
Baader UV/IR-CUT / L-Filter CMOS Optimized
Baader UV/IR-CUT / L-Filter CMOS Optimized
Baader UV/IR-CUT / L-Filter CMOS Optimized
Baader UV/IR-CUT / L-Filter CMOS Optimized
Baader UV/IR-CUT / L-Filter CMOS Optimized
Baader UV/IR-CUT / L-Filter CMOS Optimized
Baader UV/IR-CUT / L-Filter CMOS Optimized
Baader UV/IR-CUT / L-Filter CMOS Optimized
Baader UV/IR-CUT / L-Filter CMOS Optimized
Baader UV/IR-CUT / L-Filter CMOS Optimized

Baader UV/IR-CUT / L-Filter CMOS Optimized

by Baader Planetarium
SKU BAA-2961573
$87.00 - $143.00
$143.00
$87.00 - $143.00
$143.00
Price Match Policy!
  • Blocks unwanted UV and IR wavelengths for sharper stars
  • Optimized for modern CMOS sensors to prevent star bloat
  • Serves as a high-transmission Luminance (L) filter for LRGB imaging
  • Advanced anti-reflection coatings minimize halos and internal reflections
  • Available in standard 1.25" and 2" mounted sizes
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  • Description
  • FAQ
  • Specifications
  • In the Box
  • Downloads
  • Warranty

  • Baader UV/IR-CUT / L-Filter CMOS Optimized

    The Baader UV/IR-CUT / L-Filter CMOS Optimized is engineered to solve the specific challenges of modern astrophotography sensors. By providing a sharp cutoff of infrared wavelengths that cause star bloat in highly red-sensitive CMOS chips, this filter ensures your luminance data produces tight, focused stars. It combines the function of a standard UV/IR cut filter with coatings and transmission characteristics tailored to deliver maximum signal and contrast, serving as the ideal L-filter in any LRGB imaging setup.

    Engineered for Modern Sensors: Taming IR Bloat and Halos

    Standard UV/IR cut filters often have a gradual cutoff in the near-infrared, allowing unwanted IR light to reach the sensor. Because modern CMOS sensors have high sensitivity in this region, this leakage results in bloated, soft stars, obscuring fine detail. The Baader CMOS Optimized filter provides a much sharper cutoff, effectively blocking this problematic IR light to keep stars pinpoint sharp.

    A High-Transmission Window for Visible Light

    As a luminance filter, its primary job is to collect the maximum amount of detail-rich signal across the visible spectrum. Baader's advanced coatings ensure high transmission from blue to red, capturing faint galaxy arms and nebular structures without introducing a color cast. This unfiltered, broadband signal forms the high-resolution backbone of your final LRGB color image.

    Baader Anti-Reflection and Coating Technology

    Imaging with filters placed close to the sensor, as in many filter wheels and drawers, increases the risk of halos from internal reflections. The Baader CMOS Optimized L-Filter features carefully designed anti-reflection coatings to suppress these artifacts. This ensures that bright stars like Vega or Sirius don't produce distracting rings or ghost images, preserving the clean, dark background of your images.

    Baader CMOS L-Filter vs. Standard UV/IR Cut Filters

    While both filters block UV and IR, a standard UV/IR cut filter is often just a protective element, while the Baader CMOS-optimized version is a precision imaging tool. The key differences lie in the steepness of the IR cutoff and the quality of the anti-reflection coatings.

    • Standard UV/IR Cut Filter: Often has a slow, gradual IR cutoff, leading to star bloat with sensitive CMOS cameras. May lack the advanced anti-reflection coatings needed to prevent halos in modern imaging trains.
    • Baader CMOS Optimized L-Filter: Features a very sharp IR cutoff specifically to keep stars tight on CMOS sensors. Incorporates superior anti-reflection coatings to eliminate halos caused by reflections between the filter and sensor cover glass.

  • Why do I need the Baader "CMOS Optimized" L-Filter for my camera?

    Modern CMOS sensors are highly sensitive to near-infrared light, which is not focused at the same point as visible light by most telescopes. A standard L-filter can leak this IR light, causing stars to appear bloated and soft. The Baader CMOS Optimized L-Filter has a much sharper cutoff, blocking this IR light to produce significantly tighter, sharper stars.

    Will the Baader UV/IR-CUT / L-Filter help with my refractor's chromatic aberration?

    Yes, it is essential for refractors, especially achromatic and apochromatic doublets. These telescopes are not designed to bring ultraviolet and infrared light to a sharp focus. By blocking these wavelengths, the Baader UV/IR-CUT / L-Filter prevents a soft, unfocused halo from forming around stars and improves overall image contrast, even in high-end triplet APOs.

    Can I use the Baader L-Filter for visual observing?

    While designed for imaging, it can be beneficial for visual use, particularly with refractors or reflector telescopes that have corrector lenses. By cutting out-of-focus UV and IR light, it can subtly improve the snap and contrast of the view, though the effect is much more dramatic in photography.

    How does the Baader L-Filter improve my images of the Andromeda Galaxy (M31)?

    For a broadband target like the Andromeda Galaxy (M31), the Baader L-Filter allows you to capture the maximum amount of light from the core, dust lanes, and faint outer arms. By ensuring stars remain sharp pinpoints instead of bloated orbs, it allows the fine details and faint structures of the galaxy to stand out with greater clarity and resolution.

    Is this Baader filter parfocal with other Baader filters?

    Baader Planetarium designs its filter sets to be parfocal, meaning you should not have to significantly refocus when switching between them. This is a critical feature for automated imaging, saving time and preventing lost frames due to focus shift between your L, R, G, B, and narrowband filters.

    Will the Baader L-Filter work in my fast f/2 RASA or Hyperstar system?

    Yes. Baader's CMOS-optimized filters are designed to work well in fast optical systems without significant band-shifting. The high-quality anti-reflection coatings are also crucial in these setups, where the filter is placed very close to the sensor, making it effective at preventing internal reflections and halos around bright stars.

  • Available Options 2" Round Mounted, 1.25" Round Mounted
    Net weight (kg) 0.01
    Single or Set? Single Filter
    Filter mounted Mounted (LPFC 6mm)
    Filter Usage CMOS, CCD, IR-Cut, Luminance, UV-Cut
    Type of Filter Bandpass
    Special Features CMOS-optimized with Life-Coat™
    Filter Thickness (without cell) 2 mm
    CWL (Central Wavelength) UV/IR-Cut
    Transmission Range 420 – 685 nm
    AR-Coating Reflex-Blocker™ hard coated, planeoptically polished
    Suitable for f/ratio f/15 to f/1.8

  • This product is a filter only. No other accessories are included.

  • Baader Planetarium Warranty