Chroma Technology H-Alpha Filter

A 3 nm bandwidth is extremely narrow, which allows the filter to isolate the specific hydrogen-alpha light wavelength while blocking almost all other light. This results in significantly higher contrast and allows you to capture faint nebulous structures even when shooting from light-polluted urban areas.

This filter is a standard 50.8mm (2-inch) round size with a threaded mount. It is designed to be compatible with most standard filter wheels and drawers that accept 2-inch threaded filters.

Hard-sputtered coatings are much more durable than traditional soft coatings, meaning they are less prone to degradation over time. Optically, these coatings minimize internal reflections and ghosting, ensuring that the light transmission remains high and the image remains crisp.

While it is technically possible to use it visually, this filter is specifically engineered for astrophotography. Because the bandwidth is so narrow, the image will appear very dim to the human eye, making it best suited for long-exposure camera sensors.

Yes, because the bandpass is so tight, focus is critical. You will likely need to re-focus your telescope when switching to this filter, as even minor temperature shifts or mechanical flex can impact the sharpness of the image.