Baader Planetarium 4mm UBVRI CCD Photometric Imaging Filter Set, Includes U/B/V/R/I Filters, 50x50mm, Unmounted

Make your astrophotography stand out with the Baader 4mm UBVRI CCD Photometric Imaging Filter Set. This set, which includes U/B/V/R/I filters, is designed with a proprietary technology that strictly adheres to the classic Johnson/Bessel transmission specifications.

Unlike traditional filters that often have a thickness of 5mm or more, these Baader filters are crafted with dielectric layers and absorption glasses, resulting in a sleeker 4mm thickness. This reduction in thickness not only makes these filters lighter but also makes them more compatible with modern filter wheels, a significant improvement over the original 5 or 6mm thick stacks of pure colored glass.

In the past, UBVRI filters were primarily used for photodetectors, and the potential for internal reflections caused by the thick stack of cemented absorption glasses was often overlooked. However, Baader's innovative approach combines dielectric coatings with a mix of short pass and long pass filters, ensuring perfect off-band blocking into the far ends of the spectrum. This steep off-band-blocking would not be possible with pure dielectric layers over such a large transmission range.

In essence, the Baader 4mm UBVRI CCD Photometric Imaging Filter Set offers a superior solution for modern astrophotographers, providing the perfect balance between performance and practicality. This unmounted 50x50mm filter set is a must-have for anyone serious about capturing the cosmos in all its glory.