ToupTek SHO: Set of Hα, SII, and OIII filters

The ToupTek SHO kit includes three narrowband filters for the Hα, SII, and OIII lines. It allows for the separate acquisition of these channels to create SHO-palette composites.

The three filters separate the Hα, SII, and OIII emissions for channel-by-channel acquisitions. The indicated spectral lines are 656.3 nm, 671.6 nm, and 500.7 nm, respectively. These data identify the target emissions; they should not be confused with the bandwidth of each filter. This product sheet lists only complete sets and not individual filters sold separately.

Setup and Use

The choice of set is based on two criteria: its mechanical format and its bandwidth. The 1.25-inch and 2-inch sets at 6.5 nm share the same nominal bandwidth but not the same diameter. The 2-inch set at 4 nm is another option. For the 36-mm set, maintain the distinction in the technical table between Hα at 3.5 nm and SII/OIII at 4 nm, despite the commercial name «4 nm.».

The 1.25-inch and 2-inch sizes come with a frame, while the 36-mm filters are unmounted. You should therefore choose the set based on the actual mounting system in the wheel or filter holder. For 36-mm filters, the side with the black inner rim must face the telescope. This orientation guideline should be followed when verifying the size before installation.

The quartz thickness is specified as 2 mm, with an IAD coating. When preparing the setup, keep this glass, its mount (if any), and all other components of the optical train separate. The filters do not include a camera or a motorized wheel. Choosing an SHO set involves selecting spectral channels; the final image is then determined by the individual acquisitions and their assembly during processing.

Technical specifications