Baader's new LRGB anti-reflection filters deliver enhanced color separation and picture quality. Unfortunately, their obvious enhancements will likely cause many astrophotographers to re-take images of their favorite objects...
What makes the Baader filters so unique? Through an extensive coating stack plan and testing program, Baader has partnered together with the world's leading thin film coating manufacturer to create transmission curves that border on the ideal. Their ultra steep cutoffs and high transmission (>95%) allowed Baader to do something to a degree no other RGB filter set can manage - they are able to effectively isolate the important H-Beta and O-III lines. The Baader Blue filter passes virtually all of the H-Beta and O-III lines, while the Green filter is able to capture all of the O-III line, without infringing into the H-Beta line. None of the light is wasted by either filter. Along these lines, O-III is represented as it ought to be, a teal (blue-green) color, and H-Beta is captured solely in the blue. Never before has this degree of separation been achieved, and with such high transmission of both lines.
What's more, the Green and Red filter passbands nearly touch, leaving just a sharp indent to block out the primary Mercury/Sodium light pollution line at 580nm. The high transmission everywhere else delivers the shortest combined exposures possible.
Adding to their unique transmission properties, the Baader coatings were produced with another key objective - dispose of the irritating reflections present in other astro-filters. To accomplish this freedom from reflections required careful balancing of the coating stacks and further extensive testing.
The high optical quality of the Baader narrowband filters guarantees no loss in sharpness or contrast. Every substrate is fine-optically polished plane parallel to convey a smooth and precise 1/4 wavefront over the whole surface. Every filter is blocked and polished individually, not remove and cut out from a bigger plate of glass. The special custom polishing operation separates Baader filters from the lower optical quality provided by standard commercially precision polished filter substrates used by most other filter manufacturers.
Coatings are professionally applied in Germany by the most sophisticated equipment available today, ensuring high consistency for bandpass cutoffs, transmission, and out of band blocking. The anti-reflection coatings are evenly adjusted on both sides of the filters to decrease surface stresses and prevent dis-formation of the substrates. The ultra-hard ionbeam deposition guarantees the coatings will never degrade from use or typical cleaning. In contrast to many competitive filters, Baader coats every filter individually. Baader filters stay sealed at their coating edges for a long life without degradation (you can see evidence of this process by inspecting for a thin un-coated region at the very edge of the filter). While more expensive, this procedure avoids coating failures that result when filters are simply 'biscuit cut' from mass coated sheet glass, leaving ragged coating edges for moisture to infiltrate and make coatings peel away. Baader filters are intended for a lifetime of real-world use!
|Name||Baader Planetarium - 50mm Square LRGB Filters - UV/IR Cut L-Filter and Clear Filter|
|Manufacturer Part No||FLRGBC-SQ50|
|Filter size||50 mm|