IDAS Filters Type 4 BGR+L 1.25" (63995)

IDAS Type 4 BGR+L filter sets are specifically designed for tri-color (BGR) or quad-color (BGR+L) imaging, ensuring accurate color rendition that closely matches how colors are perceived by the human eye. These filters feature carefully designed bandpasses tailored for astronomical imaging, with gentle rolloffs and overlapping regions to reproduce intermediate colors, including prominent emission nebula lines. The red (R) filter incorporates some blue (B) band response to correctly render violet frequencies as purple, unlike traditional filters that misrepresent violet as pure blue. Additionally, the B/G crossover point is set slightly below 500nm to balance the colors of the two OIII emission lines (500.7nm and 495.8nm).

These filters utilize IDAS's advanced Ion Gun Assisted Deposition (IGAD) coating technology, ensuring superior durability (quartz hardness), safer cleaning, and improved stability under varying temperature and humidity conditions. IGAD coatings reduce spectrum shifts to +/-1nm compared to the +/-3 or 4nm shifts seen in standard coatings.

The unique bandpass design of IDAS Type 4 filters enables versatile imaging options:

• Conventional BGR+L imaging uses the IR-blocking L filter along with the BGR component filters. The Clear filter is used for the L-component to maintain consistent focus positions across all components.

• Full-band False Color imaging can be achieved using BGR and Clear filters without additional filtering, allowing IR-capable imaging chips to utilize their full spectral range. Note that imaging optics must also support proper IR wavelength imaging.

Specifications:

Capacity:

• Frame Size: 1.25"

Connection:

• To Telescope: 1.25"

Mount Material:

• Material: Aluminium

Coating:

• Type: Multiple coatings

General Information:

• Series: RGB Type 4

• Type: Filters

• Type of Build: L-RGB Filters

Area of Application:

• Useful for Photographs: Yes

• Visually Useful: No