There are some decent looking dichroic mirrors on ebay with unknown parameters.

I am trying to decipher the mirror/lens abbreviations so far here is an example DHSP 640 so its a Dichroic SP short pass and passes the shorter wavelengths the 640nm is the center of the tranmission /reflection graph curve so if a 90% relector its at 45% at 640nm there are others I am trying to understand so far LP is long pass the graph is opposite on plot. There are acronyms for dual pass etc but have not mastered those yet anyone knowlegable please elaborate.