Baader 36mm LRGBC Round Mounted Filter Set
The 36 mm LRGBC Round Mounted Filter Set by Baader Planetarium: These new Baader Planetarium LRGBC anti-reflection filters provide enhanced color separation and image quality while avoiding annoying halos. The only possible downside with these filters is that many astroimagers will have to take images of their favorite night sky objects again.
As a result of an extensive coating stack design and testing program, Baader has worked with the world's top thin film coating company to generate transmission curves that are close to perfect. These filters have ultra steep cutoffs and high >95-percent transmission permit Baader to effectively separate the important H-beta and O-III lines, something no other RGB filter set has been able to accomplish. The Blue filter passes essentially all of the O-III and H-beta lines, and the Green filter captures all of the O-III line while managing to not invade the H-beta line. Both filters squander absolutely no light. Because of this, O-III is seen as intended, as a teal (blue-green) color, while the H-beta is captured only in the blue. This amount of separation has never been accomplished before with such high transmission of both lines.
Furthermore, the Red and Green filter pass bands come close to touching, leaving behind nothing but a sharp notch that blocks out the primary Mercury/ Sodium light pollution line at 580 nm. Everywhere else, the high transmission produces the shortest combined exposures achievable with every detector.
From the beginning, Baader coatings were created with another important objective besides their special transmission properties in mind. Baader wanted to do away with the irritating reflections that exist in other astronomy filters. Meticulous balancing of the coating stacks plus additional comprehensive testing were needed to attain this freedom from reflections.
Baader narrowband filters assure no deficit in sharpness or contrast due to their high optical quality. Each substrate is a fine, optically polished plane-parallel to produce smooth and precise 1/4 wavefront on the whole surface. These filters are not cut from a larger glass plate. Instead, they are individually blocked and polished. This unique custom polishing distinguishes Baader filters from standard precision polished filter substrates applied by many competing filter manufacturers that deliver less than ideal optical quality.
Coatings are professionally applied in Germany using equipment with the utmost sophistication currently available, guaranteeing transmission, bandpass cutoff, and out of band blocking consistency. Evenly balanced anti-reflection coatings on each side of these filters lessen any stress put on the surfaces and keep the substrates from deforming. The super hard ion beam deposition guarantees these coatings will never deteriorate due to regular use or cleaning. These Baader 36 mm LRGBC filters are designed to be used for decades.
OPT Product Number: BA-FLRGBC-RD36
Questions & AnswersAsk a Question
I don't see that Baader states that these filters are parfocal so as to not need to focus between shots. Are they?
Lori, generally speaking they are close to parfocal. However if you are shooting with a fast focal ratio (f/4 or faster) then you will likely need to focus each time you use a new filter. If you are using something slower than f/4 you should be ok.