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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.
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 Planetarium RGB R-Filter 1.25" – CMOS-optimized
Baader Planetarium RGB R-Filter – CMOS-optimized
Baader Planetarium RGB R-Filter – CMOS-optimized
Baader Planetarium RGB R-Filter 2" – CMOS-optimized
Baader Planetarium RGB R-Filter – CMOS-optimized
Baader Planetarium RGB R-Filter – CMOS-optimized
Baader Planetarium FCCT Filter – RGB R-Filter 2" unmounted (Ø 47,4 mm)– CMOS-optimized
Baader Planetarium RGB R-Filter – CMOS-optimized
Baader Planetarium RGB R-Filter – CMOS-optimized
Baader Planetarium RGB R-Filter – CMOS-optimized
Baader Planetarium RGB R-Filter 31mm – CMOS-optimized
Baader Planetarium RGB R-Filter – CMOS-optimized
Baader Planetarium RGB R-Filter – CMOS-optimized
Baader Planetarium RGB R-Filter 31mm – CMOS-optimized
Baader Planetarium RGB R-Filter – CMOS-optimized
Baader Planetarium RGB R-Filter – CMOS-optimized
Baader Planetarium RGB R-Filter 31mm – CMOS-optimized
Baader Planetarium RGB R-Filter – CMOS-optimized
Baader Planetarium RGB R-Filter – CMOS-optimized
Baader Planetarium RGB R-Filter 50x50mm – CMOS-optimized
Baader Planetarium RGB R-Filter – CMOS-optimized
Baader Planetarium RGB R-Filter – CMOS-optimized
Baader Planetarium Baader RGB R-Filter 65x65mm – CMOS-optimized
Baader Planetarium RGB R-Filter – CMOS-optimized
Baader Planetarium RGB R-Filter – CMOS-optimized
Baader Planetarium RGB R-Filter 1.25" – CMOS-optimized
Baader Planetarium RGB R-Filter 2" – CMOS-optimized
Baader Planetarium FCCT Filter – RGB R-Filter 2" unmounted (Ø 47,4 mm)– CMOS-optimized
Baader Planetarium RGB R-Filter 31mm – CMOS-optimized
Baader Planetarium RGB R-Filter 31mm – CMOS-optimized
Baader Planetarium RGB R-Filter 31mm – CMOS-optimized
Baader Planetarium RGB R-Filter 50x50mm – CMOS-optimized
Baader Planetarium Baader RGB R-Filter 65x65mm – CMOS-optimized

Baader Planetarium RGB R-Filter – CMOS-optimized

by Baader Planetarium
SKU BAA-2961600R
$123.00 - $360.00
$123.00
$123.00 - $360.00
$123.00
Price Match Policy!
  • Red (R) filter for LRGB astrophotography
  • Available in 1.25" & 2" mounted, round unmounted and square sizes
  • Optimized for modern CMOS sensors
  • High-transmission coatings
  • Suppresses reflections and halos
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  • Description
  • FAQ
  • Specifications
  • In the Box
  • Downloads
  • Warranty

  • RGB R-Filter – CMOS-optimized

    The RGB R-Filter is a foundational component for LRGB color astrophotography, engineered specifically to meet the demands of modern, high-sensitivity CMOS sensors. Offered in mounted 1.25" and 2" cells as well as unmounted round and square formats, this filter isolates the red portion of the visible spectrum, providing the high-contrast data needed to reveal surface detail on planets and capture emission nebulae structure.

    CMOS-Optimized Coatings for Halo-Free Imaging

    Modern CMOS sensors are highly reflective, a trait that can cause halos and internal reflections around bright stars when using older filter designs. This CMOS-optimized R-Filter features advanced anti-reflection coatings on both surfaces, ensuring that light passes through to the sensor only once, preserving stellar integrity and maintaining a dark background.

    The Red Channel: A Critical Component for LRGB Astrophotography

    In LRGB imaging, the R-Filter captures the red data that, when combined with Green and Blue channels, forms a full-color chrominance layer. The red channel is particularly vital for accurately rendering the color of Mars, the Great Red Spot on Jupiter, and the deep reds of H-II regions in emission nebulae like the Orion Nebula (M42).

    Mounted, Round and Square Formats: For Every Filter Wheel

    The mounted 1.25" and 2" versions fit standard threaded filter wheels and drawers, while the unmounted 31mm, 36mm and 50.4mm round filters drop into filter carousels and wheels designed for those sizes. The 47.4mm unmounted version is made for the FCCT and compatible holders, and the 50x50mm and 65x65mm squares serve cameras with full-frame and larger sensors. Choosing a size whose clear aperture fully illuminates your sensor avoids vignetting, even with fast optical systems, ensuring your flat frames are even and your stars are round to the corners.

  • What is the CMOS-optimized R-Filter used for?

    This filter is used with a monochrome astronomy camera to capture the red (R) channel of an LRGB (Luminance, Red, Green, Blue) image. It isolates red light, which is essential for creating full-color astrophotos of planets, galaxies, and nebulae.

    Why does this R-Filter need to be "CMOS-optimized"?

    Modern CMOS sensors are more reflective than older CCD sensors. CMOS-optimized filters have advanced anti-reflection coatings that prevent halos and other artifacts from appearing around bright stars, resulting in cleaner images.

    Can I create a color image using only this R-Filter?

    No. The R-Filter is one part of a set. To create a full-color LRGB image, you will also need matching Green (G), Blue (B), and typically a Luminance (L) filter, and capture data through each one separately before combining them in software.

    What equipment do I need for the mounted and unmounted sizes?

    The 1.25" and 2" mounted filters thread into standard filter wheels and filter drawers. The unmounted round and square filters require an electronic or manual filter wheel or drawer designed for that exact size (31mm, 36mm, 50.4mm, 50x50mm or 65x65mm), and the 47.4mm version needs the FCCT or a compatible holder – none of the unmounted sizes fit standard threaded 2" cells. The wheel sits between your telescope and monochrome camera.

    How would this R-Filter improve my images of Mars with a monochrome camera?

    Mars is a predominantly red object. Using a high-quality R-filter allows you to capture maximum contrast and detail in its surface features, such as the polar ice caps and dark albedo regions like Syrtis Major Planum. It is the most important color filter for planetary imaging of the Red Planet.

    Is the R-Filter useful for imaging emission nebulae like the Heart Nebula (IC 1805)?

    Yes. Many emission nebulae glow strongly in red light from Hydrogen-alpha emissions. The R-Filter captures this signal effectively, providing strong structural detail for the red channel of your LRGB image. It can also be used to complement dedicated narrowband H-alpha data.

  • 1.25" Round Mounted

    Filter Type Red (R) Channel - LRGB
    Size 1.25"
    Format Mounted
    CMOS Optimized Yes

    2" Round Mounted

    Filter Type Red (R) Channel - LRGB
    Size 2"
    Format Mounted
    CMOS Optimized Yes

    2" Round Unmounted Filter (Ø 47.4mm, FCCT)

    Filter Type RGB Red (R-Filter)
    Size Standard 2"
    Format Unmounted
    Diameter 47.4 mm
    Coatings CMOS-optimized
    Intended System FCCT and compatible holders

    31mm Round Unmounted Filter

    Filter Type Red (R) Channel - LRGB
    Size 31 mm
    Format Unmounted, Round
    CMOS Optimized Yes

    36mm Round Unmounted Filter

    Filter Type Red (R) Channel - LRGB
    Size 36 mm
    Format Unmounted
    CMOS Optimized Yes

    50.4mm Round Unmounted Filter

    Filter Type Red (R) Bandpass Filter
    Size 50.4mm Round, Unmounted
    Series RGB CMOS-Optimized

    50x50mm Square Filter

    Filter Type Red (R) Channel - LRGB
    Size 50 x 50 mm
    Format Unmounted, Square
    Sensor Coverage Full-frame (36x24mm) and larger
    CMOS Optimized Yes

    65x65mm Square Filter

    Filter Type Red (R) Channel - LRGB
    Size 65 x 65 mm
    Format Unmounted, Square
    Sensor Coverage Full-frame (36x24mm) or larger
    CMOS Optimized Yes

    • RGB R-Filter (selected size)

      × 1

  • Baader Planetarium Warranty