Baader Filters H-alpha/OIII/SII CMOS f/3 Ultra-Highspeed 2" (75594)

The H-alpha filter passes light at a wavelength of 656 nm and is the best option for narrowband astrophotography. It enables high-contrast imaging and reveals detailed structures of nebulae, even in areas with significant light pollution.

The OIII filter is a narrowband filter with a 3 nm bandwidth centered on a wavelength of 500 nm. It is designed for observing nebulae by isolating OIII emission lines while blocking all other light, ensuring sharp and clear images.

The SII filter is a narrowband filter that passes light at a wavelength of 672 nm with a bandpass of 3 nm. It is particularly suitable for photographing emission nebulae, planetary nebulae, and supernova remnants.

If you aim to replicate the appearance of Hubble Space Telescope (HST) images, such as the iconic "Pillars of Creation" in the Eagle Nebula (Messier 16), the SII filter is an excellent addition to your setup after H-alpha and OIII filters. Together, H-alpha, OIII, and SII filters allow for tri-color narrowband imaging, creating the iconic "Hubble look." These filters also allow imaging during moonlit nights, ensuring your equipment remains active even when the moon is visible.

Specifications:

• Half-value width (nm): 3.5 & 4

Frame:

• Size: 2"

• Mount material: Aluminium

• Coating of optical system: Reflex-Blocker™

• Connection to telescope: 2"

• Filter thickness (mm): 2

Appropriate for:

• Focal ratio range: f/3.4 - f/2.3

General Information:

• Type: Filters

• Type of build: Line filter

• Series: f/3 Ultra-Highspeed

Area of Application:

• Useful for photographs: Yes

• Visually useful: No

• Nebulae and galaxies: Yes

• Moon and planets: No