Optolong LRGB Filter Set

OptolongSKU: OptolongLRGB-1.25"-1

Size: 1.25"
Sale price$317 CAD
In stock: 2 unit(s) - Most orders placed by 2PM EST will be shipped out the same day (weekdays)

Customer Reviews

Based on 1 review
Colorful Wonders

These little filters are both amazing in performance and reasonable in price. My first trial with these filters was on M31, and I am super happy with the amount of data it has captured. I also use Optolong SHO, and fortunately these LRGB filters are all parfocal with SHO, so no need to refocus between filter changes. I highly recommend them.


The Optolong LRGB filter set is designed for maximum contrast and with extremely high gradients for clear differentiation of colors. The filters divide the spectrum into red, green, blue and luminance. OIII emission overlaps on blue and green filters with maximum transmission to allow high efficiency and natural color imaging. The gap between green and red filters serves to block out the primary Sodium light pollution line at 589nm and improves color balance and separation.

  • Fine-optically polishing for double-sides ensures accurate λ/4 wavefront and <30 seconds parallelism over the both surfaces
  • Ultrasonic wave cleaning substrate with purified water removes impurities and dust effectively
  • IRO source assisted coating for durability and resistance to scratching, as well as stability on CWL (central wavelength). No deviation from temperature change.
  • Constant stringent quality testing processes - Each filter is tested by spectrophotometer and laser interferometer testing spectrum and wavefront to ensure each filter is a high-quality product
  • Optolong will spare no effort to serve our customer with outstanding quality products and best service!

31mm and 36mm filters are unmounted


  • Tavg: T>95%
  • Coating Wavelength: 300-1050nm
  • Optical Density: OD3
  • Surface Quality: 60/40
  • Transmitted Wavefront RMS: λ/4
  • Parallelism (arcsec): 30s
  • Filter Casing Width: 4.9mm

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