IDAS Filters Type 4 BGR+L 31mm

IDAS Type 4 BGR+L filter sets are meticulously crafted for tri-color (BGR) or quad-color (BGR+L) imaging, prioritizing accurate color rendition as perceived by the human eye:

• The bandpasses are meticulously tailored for astronomical imaging, ensuring gentle passband rolloffs and overlapping to faithfully reproduce intermediate colors, notably prominent emission nebula lines, aiming for "true color" representation.
• The red (R) filter incorporates some blue (B) band response to accurately render violet frequencies as violet (purple), aligning with human eye response. This corrects the representation of violet frequencies often misrepresented as pure blue by traditional filters lacking B response in the R filter.
• The crossover point of the B/G filter is deliberately set slightly below 500nm to finely balance colors in the two OIII emission lines (500.7nm and 495.8nm).

All filters employ the proprietary IDAS Ion Gun Assisted Deposition (IGAD*) coating technology, ensuring superior coating durability (quartz hardness) and safer cleaning practices. IGAD coatings enhance temperature and humidity stability of filter performance, minimizing spectrum shifts to within +/-1nm compared to the typical +/-3 or 4nm shift of standard coatings.

The unique bandpass configurations of IDAS Type 4 filters enable various imaging techniques:

• Conventional BGR+L imaging involves using the IR blocking L filter alongside each component color filter (BGR). The Clear filter serves as the L-component, maintaining consistent focus position across all components.
• Full-band False Color imaging is achieved by utilizing the BGR and clear filters without additional filtration, allowing IR-capable imaging chips to utilize their complete spectral capability. Note that imaging optics must effectively capture IR wavelengths.

Specifications:

Capacity:

Filter Size (mm): 31

Frame: unmounted

Coating of optical system: multiple

General:

Series: RGB Type 4

Type: Filters

Type of build: L-RGB Filters

Area of application:

Useful for photographs: Yes

Visually useful: No