Astronomik H-alpha MaxFR Imaging Filter

Standard narrowband filters often suffer from a 'band-shift' effect when used with fast telescopes, causing the light to miss the filter's transmission window. The MaxFR is engineered to compensate for this shift, ensuring you retain high transmission even at focal ratios as fast as f/2.

It means this filter is designed to match the focus point of other Astronomik filters in the same series. While you won't need to refocus when swapping between these specific filters, you should still check your focus periodically as temperature changes throughout the night.

Yes, this is a standard 1.25-inch mounted filter. It is designed to thread directly into standard filter wheels or onto the nosepiece of most dedicated astronomy cameras.

A 6nm bandpass is tight enough to block most light pollution and moonlight, which significantly increases the contrast of hydrogen-alpha nebulae. It strikes a balance between isolating the target signal and allowing enough light through to keep your exposure times manageable.

Yes, the filter features a specialized coating that is resistant to both moisture and scratches. It is built to withstand the rigors of field use, and it comes with a 10-year warranty for added peace of mind.