Baader 2" CMOS Optimized LRGB Filter Set

Baader 2" CMOS Optimized LRGB Filter Set

CMOS optimized Baader Planetarium 2" LRGB (Luminance/Red/Green/Blue) Filter with high transmission and each RGB color channel boasting superb contrast. Suitable for use with a vast array of telescope types, including all scopes between f/15 and f/1.8, these filters feature a balanced design that is essential for automated astrophotography. This is due to the strongly desired 1:1:1 subframe exposure times facilitated by this design. Transmission is maximized for all three RGB color channels via steep slopes at all transmission curves for enhanced contrast that matches typical quantum efficiency and s/n ratio for CMOS cameras, as well as for a stray light and reflection decrease to an implausibly low level. For even greater reflection reduction, these filters contain blackened lens edges around the entire circumference with telescope-sided black outer rim acting as a filter-lead-side-indicator.

Meanwhile, this set also includes a Luminance “L” Filter that provides 98% transmission over the entire visible spectrum while offering total obstruction of UV and IR regions, including dangerous thermal radiation, at the same time. “L” filters help imagers using digital, CCD, or CMOS cameras sensitive to red eliminate star haziness from their final results.

Since these Baader 2" LRGB filters are not cut out of a larger plate unlike more economical filters, and are each Reflex-Blocker™ hard coated and planeoptically polished independently with Life-Coat™ sealed coating edges, their coatings are not left unprotected from the elements. This makes it impossible for moisture to seep through and prematurely age the filter. Plus, with scratch-resistant Reflex-Blocker™ hard coatings applied, they can be cleaned as often as you wish with no decrease in quality over their entire life span. Developed with special attention paid to making their lenses parfocal, the thickness of these filters matches existing standards.

Baader CMOS Optimized LRGB Filter Set Highlights

• Suitable for use with a large array of telescopes, including those featuring focal ratios between f/15 and f/1.8, these Baader 2" LRGB (Luminance/Red/Green/Blue) Bandpass Filters are optimized for CMOS imaging cameras.

• Transmission for each individual RGB color channel is remarkably high in order to decrease stray light and reflections to extraordinarily low levels.

• Automated imaging tasks require identical 1:1:1 subframe exposures which are made possible thanks to a balanced design.

• Enhanced contrast for each filter comes courtesy of steep slopes at all transmission curves.

• All Baader RGB filters are coated and planeoptically polished separately with Reflex-Blocker™ hard coatings and Life-Coat™ sealed coating edges instead of cut out of a larger glass plate.

• Existing standards for filter thickness are satisfied with the parfocal filter in this set.

• Light is kept from spilling over onto the filter’s edge by a filter-lead-side-indicator in the form of a telescope-sided black outer rim and blackened edges all the way around.

• 98% of emissions originating from visible spectra between 420 nm and 685 nm are enabled passage are enabled passage with the Luminance “L” filter, while total blockage of UV and IR emissions, as well as damaging thermal radiation in the IR is also provided.

• Using the "L" filter with red-sensitive digital and CMOS/CCD cameras makes stars seem a lot less blurry.

• O-III line energy is doubled with the combined use of the "B" and "G" filters to allow the best attainable deep sky S/N through absolute maximum transmission.

• "R" filters offer complete blockage all infrared and near infrared light from 680 nm to 1200 nm while providing maximum H-Alpha and SII object transmission.

• The “G” and “R” filters both block undesirable light coming from Mercury and Sodium vapor street lamps emitting at 580 nm, thus enabling peak color balance and separation, as well as a blacker sky background.

• Compatible with classic CCD camera technology in addition to newer CMOS camera models.

About the Luminance "L" Filter

The obstruction of UV and IR light originating from the extreme non-visible ends of the spectrum is the main purpose of the Baader Luminance "L" Filter. This includes complete blockage of damaging thermal radiation in the infrared, as well as the prevention of blurry stars when working with digital or CCD/CMOS red-sensitive cameras. Meanwhile, all visible spectral areas between 420 nm and 685 nm are allowed to pass at a 98% transmission rate.

About the Red "R" Filter

With the Red "R" Filter, only transmissions from 595 nm to 690 nm wavelengths are permitted to pass, including those of deep sky objects in the H-Alpha line. While there is an intentional overlap between the "G" and "B" filters in terms of spectral emissions allowed to pass, a purposeful gap between the shortest part of the "R" region and the longest part of the "G" region results in the exclusion of a wide range of unwanted light emissions from street lamps and other terrestrial sources. Red "R" filters fully obstruct the NIR and IR from 680 nm up to 1200 nm while keeping maximum transmission of H-Alpha and SII emissions extremely high.

About the Green "G" Filter

Best suited for imaging O-III emission line objects using CMOS monochrome cameras, Green "G" filters transmit wavelengths between 490 nm and 580 nm. Despite the previously mentioned "G" and "B" filter overlap, the crucial H-Beta and O-III emission lines are clearly independent from one another. Although there are no critically important emission lines to be found in the vicinity of 580 nm, Mercury and Sodium vapor street lights do emit from this region. However, thanks to Baader's RGB filter design, these unfavorable emissions are cut off almost entirely, resulting in a darker sky background as well as better color balance and separation.

About the Blue "B" Filter

Of the three Baader RGB filters, The Blue "B" Filter allows the transmittance of the shortest wavelengths (400 nm to 510 nm). This is especially useful for applications involving objects emitting from the H-Beta line (486 nm) such as the Horsehead nebula. Like the "G" filter, the "B" filter also passes O-III emissions (501 nm). When used in combination, these two filters provide double the O-III line energy for unmatched deep sky S/N via extremely high peak transmission.