Announcement Baader Narrowband F

Announcement
Baader Planetarium LRGBC Filters
for SBIG Cameras
July 15, 2008

Baader Planetarium has added LRGBC filters to their inventory of high quality imaging accessories and SBIG is pleased to offer these sets for our ST and STL series cameras. The new LRGBC filters are parfocal with Baader's existing line of narrowband filters and they are very reasonably priced, particularly in light of their overall professional design and quality. Peak transmission of 98% is achieved for each of the color pass bands. Reflections have been minimized or eliminated. Equal exposure times may be used for all three colors for easier image reduction using a single length dark frame. Each filter is optically polished to 1/4 wave flatness over the filter surface for exceptional image quality. The hard coatings are made for being used outdoors. In one test, the filters were immersed in boiling water for an hour without damage to the coatings or glass.

SBIG is offering these filters in 1.25" and 50.8mm sizes. The 1.25" filters include a custom filter cell designed not to pinch or warp the filter glass. These will fit in our CFW9 and CFW10 filter wheels. The unmounted 50.8mm round filters are designed to drop into the SBIG STL camera's internal filter carousel, or into the 8 position FW8 also made for the STL. The 50.8mm diameter round filters provide optimum coverage of the larger CCDs such as the 11000 and 6303. An intermediate size (2" OD filter cell with 48mm threads) is also available on request.

Baader's innovative new designs and features, together with the very latest thin film coating technologies, result in outstanding performance, efficiency, and image quality. Baader filters are unique, in that they utilize true optically polished flat substrates. Ultra-thin precision cells deliver the maximum clear aperture and minimize vignetting. Ion beam hardened coatings ensure your filter will withstand real-world use and repeated cleaning - they are tough enough to survive boiling water!

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.

Durability has always been a hallmark of Baader Planetarium. The multi-layer dielectric coatings are plasma assisted and Ion beam 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. Baader Filters will truly last lifetimes.

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 (1¼" Filter clear aperture is 27mm!). The special threading has been designed to fit the wide variety of eyepieces and accessories (there is significant variation between the 1¼” 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.

Despite the high quality and advanced technology, Baader Planetarium filters are affordable. By leveraging high volumes across all filters in the Baader family, these filters can be offered at very reasonable prices.

Comments from experienced imagers after using the Baader LRGB filters:

"I am more than satisfied with the performance of the new Baader filter set. The absence of any reflections from bright stars makes clean-up procedures obsolete for many objects displaying foreground stars. The simple 1:1:1 RGB weighting together with a distinct color separation supplies deep star colors and fine details in galaxies and nebulas." -Johannes Schedler, Austria

For the latest prices on all Baader Planetarium filters, see our current Price List