H-Alpha 35nm CCD Filter 2 inch
Baader's 35nm H-Alpha passfilter enables high-contrast deep sky images of Ha regions. It's medium 35nm FWHM bandwidth is ideal for interline CCD cameras. The lower sensitivity of interline transfer CCDs benefits from the more efficient 35nm FWHM. The sharp bandpass and 90%+ transmission coatings make the Baader H-Alpha filter superior to common coloured glass filters.
Baader Planetarium filters are made from striae-free substrates, and fine optically polished flat to within 1/4 wave p-v over the entire surface, plane parallel to within 30 seconds of arc. This important and unique custom step adds cost, but the result is a filter that maintains the full wavefront quality of the telescope without double images or ghosting, even at high magnifications. Such high flatness enables Baader filters to be used far in front of the focal plane, ahead of star diagonals and digital cameras. They are particularly well suited for attachment to the nosepiece of the Maxbright Binocular Viewer (other manufacturer's filters must be used in pairs, attached to the eyepieces).
The multi-layer dielectric coatings are plasma-assisted and Ionbeam-hardened using the latest technology (the coatings are harder than the glass substrate itself!). Baader filters withstand repeated real-world exposure to the elements and physical cleaning.
Baader Planetarium filters are truly designed to be stacked and combined. This is possible due to the high optical quality and highly efficient anti-reflection multicoatings. The ability to combine filters opens up many exciting possibilities, permitting unique spectral characteristics unachievable with any single filter.
We are also happy to offer the Baader 35nm Dielectric Coated Filter as an internal Energy Rejection Filter for use with Daystar rear mounted solar H-Alpha filter systems. We have tested the 35nm filter with refractors up to 152mm and found the resulting filtered light to be cool and safe for use as an internal ERF. This offers a low cost alternative to large and expensive front mounted ERF's while maintaining a high level of optical quality for the optical system. Please contact us for further details.
