The new Baader CMOS-optimized O-III 4nm / 6.5nm filter is a precision-grade ultra-narrowband filter with a high transmission at the Oxygen-III line at 500.7nm. It is designed to work very well with modern highly-sensitive astronomy cameras and telescopes with focal ratios between f/15 to f/3.4.
The ultra-narrow 4nm bandpass make these ideal for imaging under light-polluted skies. The 6.5nm versions are recommended for most cases where there is not a great deal of light pollution.
Baader's CMOS-optimized filters have excellent halo and reflection control, increased contrast and even more narrow passbands than previous generations. These filters set the new standard for monochrome astrophotography with CMOS sensors.
Baader CMOS-optimized filters - advantages
- Very high contrast due to steep edges of the coating
- Reflex-Blocker coatings to minimize reflections caused by correctors, reducers and other optical elements
- Standardized thickness for maximum possible parfocality - less need to refocus due to different filter thicknesses
- Blackened edges with side markings in the form of a black outer rim on the telescope side
- Each filter is individually fine-polished and coated with sealed coating edge, preventing moisture ingress
- Life-Coat for hardness and age-resistance, making the filters able to withstand tougher conditions for longer
For more information on Baader's new generation of CMOS-optimized filters, check out this blog post!
|Half bandwidth||4 nm / 6.5 nm|
|Suitable for f/ratio||> f/3.4|
Reflex-Blocker hard coated, planeoptically polished
|Filter thickness 1.25", 2", 31 mm, 36 mm||2 mm (without cell), 6 mm with cell|
|Filter thickness 50.4 mm, 50 x 50 mm, 65 x 65 mm||3 mm|
|Filter size||1.25", 31 mm, 36 mm, 2", 50.4 mm round, 50 x 50 mm square, 65 x 65 mm square|