About this product
Baader's new Narrowband CCD Emission Line & H-Alpha Filters deliver the absolute highest contrast deep sky images in H-Alpha, H-Beta, Oxygen III, and Sulfur-II, with the shortest exposures possible. Their ultra-narrow bandwidths have extremely high transmissions, while completely rejecting light pollution as well as the important blocking of longer wavelengths.
The high optical quality of Baader narrowband filters guarantees no loss in sharpness or contrast. Each substrate is fine-optically polished plane parallel to deliver a smooth and accurate 1/4 wavefront over the entire surface. This special custom polishing operation sets Baader filters apart from the standard commercially precision polished filter substrates used by most other filter manufacturers.
In addition to their special transmission properties, the Baader coatings were developed with another key goal in mind - to reduce the annoying reflections present in other astro-filters. To achieve this, along with excellent out of band blocking, required careful design and testing of the coating stacks.
Coatings are professionally applied in Germany by the most sophisticated equipment available today, ensuring high consistency for bandpass centering, transmission, and out of band blocking. The anti-reflection coatings are designed to prevent halos and balanced to prevent deformation of the substrates. The ultra-hard ionbeam deposition ensures the coatings will never degrade from use or normal cleaning.
|Average Rating (3 Reviews): |Baader 2” Mounted 7nm Ha Filter
Wednesday, 24 February 2021 | Kevin
I had been using an Astronomik 12nm Ha Clip-in filter with my DSLR and wanted to go narrower at reasonable cost. I wanted a 2” threaded filter to go with my Redcat 51 and decided to go with the Baader 7nm filter. There is a notable difference between the 12nm and 7nm filters which has justified my decision to go with this filter. The 7nm filter isolates more fine Ha nebulosity and detail which is rewarding. The filter screws perfectly into the Redcat 51, the only minor grievance is that when removing the filter, the threaded portion grips more tightly than other 2” filters and more force is required to release it. Due to the narrower bandwidth, achieving tight focus is more time consuming as you have to do test exposures of at least 10-30 seconds to get decent diffraction spikes. Additionally, the narrower bandwidth produces smaller stars. Overall, I am delighted with my choice and would recommend this filter to others who are thinking of buying it.
Brilliant quality Narrowband filters!
Wednesday, 21 August 2013 | Kayron
I bought the Hydrogen-Alpha (7nm), Sulphur-II and Oxygen-III filters for full Narrowband imaging on my ATIK 383L+ Monochrome CCD camera. These filters work extremely well and are very well priced. They produce no internal reflections and are parfocal (focus the camera with one and the other two will be focused at the same point).
Astrodon filters are meant to be of narrower bandwidths and therefore produce better contrast but to be honest, I do not think they are worth the extreme amount of money they cost over these Baader filters, which can produce stunning images.
Hydrogen Alpha Perfection
Thursday, 19 May 2011 | Mike
The 2" Hydrogen Alpha (7nm) is a beautiful filter that even comes in a beautiful box.
It feels well made and hasn't given me any trouble with internal reflections. It lets through a tight enough portion of Hydrogen Alpha wavelength light to give high contrast results even when imaging over strongly (floodlit, moonlit, airport) light polluted skies.
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