Chroma Ha3LRGB 1.25" mounted filter set (Chroma Technology, SKU: CT-27109-Ha3LRGB-1.25M) includes five filters intended for LRGB astrophotography with a monochrome camera. The four broadband filters are complemented by a 3 nm H-alpha filter, enabling the structures of emission nebulae to be recorded at the 656.3 nm hydrogen line. Each filter is installed in a threaded 1.25" cell designed for compatible filter wheels, filter drawers and other accessories with an M28.5 × 0.6 filter thread.
• set of five filters for LRGB and H-alpha astrophotography
• 3 nm H-alpha filter providing high contrast and effective background-light suppression when imaging emission nebulae
• matched LRGB filter passbands designed for producing images with natural colors
• durable hard coatings applied by reactive magnetron sputtering
• primary filtering coatings applied to the front surface and anti-reflection coatings applied to the rear surface
• single optical substrates with a thickness of 3 mm
• parfocal design with other Chroma astronomy filters, except LoGlow filters
• 1.25" cells with external and internal M28.5 × 0.6 threads
• standard version designed for f/4 or slower optical systems
• total cell height of 7 mm
• Chroma luminance L filter, 1.25", mounted
• Chroma red R filter, 1.25", mounted
• Chroma green G filter, 1.25", mounted
• Chroma blue B filter, 1.25", mounted
• Chroma 3 nm H-alpha filter, 1.25", mounted
• manufacturer: Chroma Technology
• set type: Ha3LRGB
• intended use: astrophotography with monochrome cameras
• number of filters: 5
• filter types: luminance L, red R, green G, blue B, H-alpha
• H-alpha filter central wavelength: 656.3 nm
• H-alpha filter bandwidth FWHM: 3 nm
• filter size: 1.25"
• nominal diameter: 31.75 mm
• cell outer diameter: 31.04 ± 0.03 mm
• minimum clear aperture: 26.50 mm
• shape: round
• configuration: mounted
• cell external thread: M28.5 × 0.6
• cell internal thread: M28.5 × 0.6
• optical substrate thickness: 3 mm
• total cell height: 7 mm
• coating technology: reactive magnetron sputtering
• recommended optical systems: f/4 or slower
• SKU: CT-27109-Ha3LRGB-1.25M
• note: the H-alpha filter is not intended for solar observation
The 1.25" cells facilitate installation and safe handling of the filters, while the complete set allows the natural colors of an LRGB image to be combined with clearly rendered structures of emission nebulae.
