The new Baader CMOS-optimized S-II 4nm Highspeed F/3 filter is a precision-grade narrowband filter with a high transmission at the Sulphur-II line at 671.7nm. The Highspeed F/3 versions are specifically designed to work very well with modern highly-sensitive astronomy cameras and telescopes with extremely fast focal ratios between f/3.4 and f/2.3 such as the Sharpstar Hyperbolic Newtonian astrographs. The ultra-narrow 3.5nm bandpass makes this ideal for imaging under light-polluted skies.
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|
|Suitable for f/ratio||f/3.4 to f/2.3|
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|
|SKU 31 mm||BA2961501|
|SKU 36 mm||BA2961502|
|SKU 50.4 mm round||BA2961504|
|SKU 50 x 50 mm||BA2961505|
|SKU 65 x 65 mm||BA2961506|