Baader Planetarium 1.25" Clear Focusing Filter

This very useful addition to the Baader filter range is intended for the luminance channel in astro imaging. Using narrowband filters can often result in slightly dimmer images, which can be difficult to focus. You can now use this filter to focus perfectly with a bright image and since they are also parfocal, switch to a different narrow band filter without loosing the focus. This filter has the same substrate thickess as the other Baader filters.