Multi pass narrowband filter SV240 arrives

The SV240 multi-bandpass filter is designed for astrophotography in urban environments, where it isolates key emission lines such as Hydrogen-Alpha (Ha), Oxygen III (OIII), and Hydrogen-Beta (H-Beta) to reduce the interference of light pollution. The filter is suitable for capturing images of deep-sky objects, including galaxies, reflection nebulae, emission nebulae, and star clusters. It allows astrophotography in areas with high light pollution, such as Bortle 8 locations, without the need to travel to less polluted areas.

Presale of the SV240 multi pass narrowband filter from SVBONY goes live on Sep 27, 2024

This multi-bandpass filter transmits the main emission lines Ha, OIII, and H-Beta, enhancing the signal-to-noise ratio and contrast in the images. The filter also enables users to capture color images with One-Shot Color (OSC) cameras without the need to combine images taken with multiple filters. In addition, the SV240 filter passes near-infrared (NIR) light, enabling the capture of deep-sky objects that cannot be imaged with filters that do not transmit in the NIR region. The NIR transmission extends up to 1100nm, which includes wavelengths less affected by artificial light pollution.

The filter has a full width at half maximum (FWHM) of 24nm, 20nm, and 115nm across its filtered wavelengths, providing high transmittance while effectively blocking light pollution. The wide wavelength range of 300nm to 1100nm allows the filter to isolate light pollution bands while capturing images across a broad spectrum. The filter’s multilayer coating contributes to its performance in reducing the effects of urban light pollution and maintaining high transmittance in the core wavelengths.

The SV240 filter has a clear aperture of 44mm and a substrate thickness of 2mm, with a surface quality of 60/40 and surface parallelism of 1/4λ. Its thread size is M48x0.75, and it weighs 12.5g. The filter’s blocking capabilities include more than OD5 at 300-450nm, more than OD4 at 560-620nm, and more than OD3 at 940-1100nm. The peak transmittance for the key emission lines includes 95% at 486.1nm, 92% at 495.9nm, 85% at 500.7nm, and 95% at 656.3nm.

In terms of light pollution resistance, the SV240 can be used in environments with artificial lighting, including conditions up to Bortle 8. The filter’s ability to block light pollution from 300nm to 1100nm allows it to capture a range of astrophotography targets in urban settings, including galaxies, nebulae, and star clusters. The wide wavelength range also ensures compatibility with modern high quantum efficiency cameras, such as those using IMX585 and IMX464 sensors, which are optimized for capturing images in the NIR region.

The SV240 multi pass narrowband filter will be available for presale starting Sep 27, 2024. The filter provides high transmittance with peak values of 95% at 486.1nm and 656.3nm, and effective blocking with optical densities of over OD5 at 300-450nm and over OD3 at 940-1100nm, allowing detailed imaging of deep-sky objects in light-polluted environments.

SV240 2inch Multi-Narrowband Filter specifications

• Brand: SVBONY
• Model: SV240
• Name: Multi-Narrowband Filter
• Size: 2-inch
• Substrate Thickness: 2mm
• Clear Aperture: 44mm
• Wavelength Range: 300-1100nm
• FWHM: 24nm & 20nm & 115nm
• Blocking: >OD5@300-450nm；>OD4@560-620nm；>OD2>690-750nm； >OD3@940-1100nm
• Peak Transmittance: T＞95%@486.1nm；T＞92%@495.9nm；T>85%@500.7nm；T>95%@656.3nm； Tavg>95%@830-870nm
• Surface Quality: 60/40
• Surface Parallelism: 1/4λ
• Thread: M48x0.75
• Single Thread: Yes
• Net Weight: 12.5g / 0.44oz /0.027lb
   

Wavelength range of the SV240 filter