Baader 36 mm CMOS Optimized RGB Filter Set

Baader CMOS Optimized RGB Filter Set

Astro-imaging with modern CMOS cameras using Baader RGB color filters is achievable for nearly all telescopes independent of optical speed. In fact, these filters are compatible with any telescope that has a focal ratio between f/15 and f/1.8. Notable features include a balanced design, steep slopes at all transmission curves, blackened lens edges with telescope-sided black outer rim around the entire circumference. Highly coveted 1:1:1 subframe exposures, a must for automated imaging, are realized due to this filter's balanced design. Remarkably low levels of stray light and reflections, as well as peak color contrast that matches regular CMOS QE and s/n ratio, are both attainable through steep transmission curve slopes. Finally, unwanted reflections are lessened even further thanks to blackened lens edges with black outer rim on the telescope side that serve as a filter-lead-side-indicator.

For cheaper filters made by other manufacturers, one of the main causes of premature aging is the moisture accumulation stemming from micro-cracks formed around all edges. These micro-cracks develop as a result of being cut from a larger plate instead of individually coated and planeoptically polished with Reflex-Blocker™ hard coatings and Life-Coat™ sealed coating edges like Baader’s CMOS Optimized RGB Filters. Furthermore, because Reflex-Blocker™ coatings are resistant to scratching, the quality of these filters will remain high indefinitely regardless of cleaning frequency. Lastly, current standards for filter thickness are met with these parfocal filters.

Baader CMOS Optimized RGB Filter Set Highlights

• These RGB (Red/Green/Blue) Bandpass Filters from Baader Planetarium are CMOS camera optimized and work with telescopes ranging from the very slow (f/15) to the very fast (f/1.8).

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

• Balanced 1:1:1 subframe exposures, vitally important for performing automated imaging tasks, can be captured by using these filters.

• Each filter in this set contains transmission curves with steep slopes for improved contrast.

• Separately coated rather than carved out of a larger glass plate, these Baader RGB filters are all planeoptically polished with Reflex-Blocker™ hard coatings and Life-Coat™ sealed coating edges.

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

• All-around blackened edges and a black outer rim on the telescope side serving as a filter-lead-side-indicator limits reflections even more by assuring that no excess light falls onto the edge.

• Achieve optimal deep sky S/N output via the ultimate peak transmission provided by the double O-III line energy you get from the joint use of the “B” and “G” filters.

• Infrared and near infrared spectral areas from 680 nm to 1200 nm are fully obstructed with the use of this set’s “R” filter, while targets originating from H-Alpha and SII regions are permitted passage.

• The impediment of annoying Mercury and Sodium vapor street lights emitting at 580 nm by both the "G" and "R" filters allows for a darker sky background and unmatched color balance and separation.

• Suitable for use with older CCD cameras despite being designed specifically with modern CMOS technology in mind.

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.