Optolong H-alpha, O-III and S-II CCD 12nm filters set 31,8mm

Many faint objects such as nebulae emit light at particular wavelengths: H-alpha at 656nm, O-III at 501nm and SII at 672nm. Using Optolong H-alpha, O-III and S-II CCD 12nm filters set 31,8mm it is possible to "select" only those wavelengths (with a bandwidth of 12nm) removing all other frequencies. 

Photographic use: this filter set is perfect for anyone who owns a monochrome CCD camera and wants to make color images using the trichromy technique. Using monochrome CCD camera, you record 3 images (one for each filter) which can then be added together with appropriate software (indicating that each filter corresponds to one of the R, G and B channels) to reconstruct the color image! Selecting only particular wavelengths and eliminating light pollution, these filters dramatically increase the contrast of the image so that the background sky turns black making appear areas and details of the nebulae that are not visible without a filter. The filter also decreases the size of the stars highlighting even more nebulae.

This filters set is also perfect for use with achromatic or semi-apochromatic refractors that, because of the chromatic aberration, are not usually indicated for the long-exposure photography. But, using these filters the deep-sky photography becomes not only possible but also provides excellent results since the narrow bandwidth practically cancels the effect of chromatic aberration.

Visual use: because of the very narrow bandwidth, the light that reaches the eye is greatly reduced so this filter is not suitable for visual use.

Technical specifications:
Set H-alpha, O-III and SII CCD 12nm for narrowband trichromy
It cancels the light pollution, making the sky background dark
Anti-reflective multi-layer coating
Quality substrate not to introduce aberrations in the images

How to use the filters:
Our filters are available in 2 diameters: 31.8mm and 50.8mm. These standards are commonly used by telescopes and their accessories. For example, depending on their function, they can be used with a CCD ora a DSLR camera (using appropriate photo adapters), but also screwed to optical accessories such as eyepieces or diagonals. Warning: 31.8mm filters do not work with 50.8mm diameter accessories and vice versa (unless there are special adapters). When you choose the version of your filter, be careful to identify the diameter compatible with your equipment.