It seems Astrodon has had a bit of a dummy spit because the Baader 7Nm Ha filter is considerably cheaper.
article
here
My points.
For faster systems the Baader rules as its peak is on the high side, improving performance for fast F ratios. Astrodon says it will suffer in F7 to F10 systems. The slowest system I have is my 10 inch F5.6. I also have a 6 inch F3.6 SN and the mighty 300mm F2.8 Flourite lens, which definately is happiest with a filter optomised for fast systems.
As for out of band blocking, its no secret that one should use a uv/ir filter in addition to any nebula filter, or HA filter, which addresses the out of band issue.
I just find it odd that a company like Astrodon feels the need to make a song and dance about a company that "dares" to enter its market of narrowband filters.
What must really irk Astrodon is that Sbig now offer Baader filters as well as Astrodon, see
http://www.sbig.com/sbwhtmls/announc...rowband_f2.htm
Note that Astrodon's test images were on a "slow" RC system, not in a faster < f4 system. Id like to see a similar shoot out on such a faster system, I think you will find the Baader will hold it's own quite well.
Scott