ToupTek LRGB: Complete set of 1.25-inch, 36 mm, or 2-inch filters

The ToupTek LRGB filter set combines the luminance, red, green, and blue channels for imaging with a monochrome camera. It is available in three sizes: 1.25 inches, 36 mm, and 2 inches.

The four filters correspond to four separate captures: luminance, red, green, and blue. Using them with a monochrome camera allows you to construct a color image from these channels. The complete set therefore includes all four elements, not just a single filter selected from a list. The camera and filter holder must be selected separately depending on the imaging configuration.

Setup and Use

The choice between the 1.25-inch, 36-mm, and 2-inch sizes primarily depends on the housing in which the filters will be installed. The two sizes expressed in inches are mounted in threaded aluminum alloy frames. The 36 mm size is unmounted. This difference in construction must be taken into account when selecting the filter wheel or filter holder; simply comparing diameters is not sufficient to determine mechanical compatibility.

The manufacturer specifies the following transmission ranges: 420 to 690 nm for luminance, 595 to 695 nm for red, 495 to 580 nm for green, and 400 to 510 nm for blue. These ranges describe the spectral distribution of the game’s channels. They do not correspond to a set of narrowband SHO filters, which operate on a different principle and select different spectral lines.

The filters are made of 2 mm-thick quartz with IAD coatings. For the 36 mm unmounted version, the manufacturer specifies the installation orientation: the side with the black inner border must face the telescope. Keep this in mind during installation. Before choosing a size, check your filter wheel’s mounting system and the number of slots; all four filters must fit the holder provided with your LRGB kit.

Technical specifications