Optolong SHO 3nm 2 inch filter set

Description

Narrowband filter set SHO 3nm for astrophotography

The Optolong SHO 3nm 2 inch filter set includes SII 3nm, H-Alpha 3nm and OIII 3nm narrowband filters mainly used with astronomical monochrome cameras and custom DSLR cameras. The 2 inch filters are threaded and therefore mounted, while the 36 mm filters are unmounted.

The extra narrowband SII 3nm filter is designed for observing nebulae and passes through a bandwidth of 3nm centered on a wavelength of 672nm.

The extra narrowband H-Alpha 3nm filter is a popular narrowband filter that allows a bandwidth of 3nm to pass at a wavelength of 656nm. Better choice of narrowband H-Alpha astrophotography filter for the highest contrast and to detect fine nebula details.

The extra narrowband OIII CCD 3nm filter has a bandwidth of 3nm, centered on a wavelength of 500nm, which corresponds to the OIII emission line. OIII transmits 495.9nm and 500.7nm and is a blue-green color filter. Many images of, for example, planetary nebulae and supernova remnants have been made with only H-alpha and OIII filters. They show a lot of structural detail, but have natural colors and look like an RGB image.

Halos in OIII

As is well known, an OIII narrowband filter has always been a problem in the aspect of halos. With the experience of the 7nm narrowband filter, the halo of the OIII 3nm filter is optimized by optimizing the coating technology. It follows that Optolong also performed a qualitative halo test in the veil nebula’s bright star. For that reason, the original photo shows that OIII 3nm performs better in the bright star.

How to read the chart:

• Horizontal axis is the wavelength in nanometers (nm).
• Vertical axis is the transmission in %.
• The blue line shows the transmission of OIII 3nm. The H-Alpha 3nm line is shown in green. Finally, the SII 3nm filter line is shown in red.

The filters reliably block certain wavelengths of light. In particular those produced by artificial light. Examples include: mercury vapor and high and low pressure sodium lamps as well as unwanted natural light caused by neutral oxygen emissions into our atmosphere.

Delivery of the Optolong SHO 3nm 2 inch filter set includes:

• SII filter 3nm 2 inch mounted
• H-Alpha filter 3nm 2 inch mounted
• O-III filter 3nm 2 inch mounted
• 1 plastic storage box