Baader 2" UV-IR Cut "L" filter #2459210A-imaging filter FUVIR-2
Item No. 724-58830
Eligible for Scope City Rewards at Check-out
Manuf. No. Baader Planetarium FUVIR-2
Baader 2" UV-IR Cut "L" filter #2459210A-imaging filter, FUVIR-2
The Baader Planetarium UV-IR Cut Filter has an unmatched 98% Average Transmission! Freedom from ghost images (very low reflection multi-coating, Striae-free, and plane-parallel substrate).
Extremely Sharp Cutoff at 690nm (leaves all the visible red, including the important 656nm H-alpha emission line). True optical quality glass substrate and coatings.
The Baader Planetarium UV-IR Cut Filter has a sharp cutoff below 400nm. Eliminates violet halos around bright stars (more effectively than simpler so-called Minus Violet photographic filters).
Baader Planetarium has introduced the world's finest UV/IR cut filter. This filter is a must for all digital imaging with Digital Cameras, CCD Cameras, and modified WebCams. Also useful for protecting valuable H-Alpha filters from heat stress and damaging IR (Daystar, etc).
Due to their extremely high optical quality, these filters may be stacked and used far in front of the focal plane (necessary for imaging uses). Like the Baader Planetarium Contrast-Booster, the UV-IR-Cut filter uses the very latest coating technology, to deliver the finest filtration quality - and lifetime durability.
True Optical Quality: Baader glass substrates are of true optical quality. Most other filters are merely made from raw flame-polished, "optically flat", or sometimes a top quality commercially polished filter glass (fine for camera filters), resulting in wavefront deformations that damage image sharpness and contrast when used with telescopes. Baader Planetarium filters are made from striae-free substrates, and actually 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. Critical to maintaining this level of flatness are Baader's carefully balanced coating designs, which prevent coating surface stresses from warping the substrate. 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).
Filter Durability: Filter durability has always been a hallmark of Baader Planetarium. 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. Users need not leave their precious filters dull and dust encrusted to avoid cleaning - Baader filters may be used and cleaned without fear. We have heard sad stories from owners of other simpler soft-coated dielectric filters, who have seen their coatings degrade from normal exposure to moisture, or wiped away from routine cleaning. Some manufacturers even resort to sandwiching their delicate coatings in between two layers of glass (and risking blurred double images as well as eventual degradation from the edges inward). Baader Filters will truly last a lifetime.
Stackability: Unlike other filters, 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.
Special Filter Cell: Baader's special filter cell design offers unique features that enhance their reliability and usability. Though difficult to produce, the ultra-thin filter cell results in the maximum possible clear aperture, in order to minimize vignetting (1.25" Filter clear aperture is 27mm, 2" Filter aperture is 45mm). The special threading has been designed to fit a wide variety of eyepieces and accessories (there is significant variation between the 1.25" filter threading used by eyepiece and accessory manufacturers). The front 'crown' of the filter incorporates milled notches which make handling and threading the filter a more secure operation in the dark.