Hutech Light Pollution Filters

Hutech IDAS Light Pollution Suppression (LPS) Filters.
 

IDAS filters (formerly marketed under the Tokai brand name) are manufactured in Japan especially for astronomical applications. Light pollution suppression (LPS) filters are designed to suppress the common emission lines generated by artificial lighting, yet allow the important nebula emission lines to pass, thus enhancing the contrast of astronomical objects, particularly emission nebulae. Unlike other light pollution suppression filters, IDAS (formerly Tokai) filters are specifically designed for balanced color transmission using the IDAS unique Multi-Bandpass Technology (MBT) process. The balanced transmission allows color photographs to be taken with minimal color cast to broadband emission objects such as stars, galaxies and globular clusters. CCD imaging can also benefit, because although CCD imagers can already shoot through light pollution to some extent, including an LPS filter to the setup gives an added (signal-to-noise) edge
.
IDAS LPS filters - Sky & Telescope
Hot New Product for 2000! (December 2000 issue)
Full Review in June 2001 issue!

Note, however, that light pollution suppression filters are not a perfect substitute for dark
skies. LPS filters are available for 1-1/4" and 2" (48mm) eyepieces, as well as in numerous sizes to accomodate most popular camera lenses.

P31.7(1.25")
P48(2")
P48SCT(SCT Version)
P52
P72
P77
P82
 

You are buying from an authorized Hutech/Borg UK dealer.