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Astrodon Gen2 I-Series LRGB Tru-Balance Filter Set - 31 mm Unthreaded Insert - LRGB2-I31R

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About Astrodon Gen2 LRGB Filters

Astrodon filters are high performing, durable filters that provide significant aid for astrophotography and research pursuits. Each filter is constructed using a highly innovative process with a single high quality 3 mm thick fused silica substrate and full hard oxide sputtered coatings. Ideally suited for back-thinned and Sony detectors, Astrodon LRGB filters simplify imaging by requiring only a single exposure time, plus one corresponding dark exposure, rather than one for each color. This saves valuable imaging time and results in improved color separation and "Tru" color balance.

Astrodon 31 mm Gen2 I-Series LRGB Filter Set

Designed to roughly emulate the flux of Interline CCD detectors with compensation for the solar photon flux, Astrodon LRGB Gen2 I-Series Tru-Balance filters are able to offset the lower red response of these Interline detectors that impacts the Green and Red filters. The Luminance and Blue filters in both the I-Series and E-Series filter sets are identical. Approximately 1:1:1 RGB color combine weights within possibly 10% are thus enabled. Although this can never be perfect, it does allow all of your RGB data to be captured in a single exposure time with just one equivalent dark exposure time. This simplifies the imaging process by preserving valuable imaging time.

Astrodon 31 mm Gen2 I-Series LRGB Filter Set Highlights

  • Set includes Luminance with UV and NIR blocking, as well as Red, Green, and Blue filters
  • 31 mm unthreaded insert
  • 3 +/-0.025 mm single 1/4 wave fused silica substrate before coating
  • 30 arcsecond parallelism
  • Approximately equal color combine weights for G2V white-point for Interline (I) detectors
  • Equal RGB exposures with one corresponding dark exposure time
  • Improved color separation (see transmission spectra)
  • Improved color rendition for color theory based galaxies
  • Virtually eliminates reflections and star halos
  • Spectral "gap" between green and red filters minimizes the impact of light pollution
  • Maximum efficiency blue filter with lower UV
  • Correct "teal" OIII color for planetary nebulae (OIII signal over 97% in blue and green)
  • Parfocal with both Astrodon's high performing narrowband and near-infrared Luminance filters
  • Features solid, ultra-hard edge-to-edge sputtered coatings
  • Proudly manufactured in the USA

Astrodon E-Series vs. I-Series LRGB Tru-Balance Filters

The sensor your camera uses determines whether you need the I-Series LRGB filter set or the E-Series LRGB filter set. Cameras with Progressive Scan sensors (including front as well as back illuminated sensors) are compatible with E-Series filters, while cameras with Interline Transfer sensors are compatible with I-Series filters. Identifying the type of sensor your camera uses is not always an easy task. This information is frequently missing from both the specification and the manual. Therefore you may need to check with the sensor manufacturer. If you still can't identify the type of sensor employed by your camera, it is best to use the E-Series filter set.