Orion Ultrablocks

Anyone familiar with the history of these? I have a couple of them purchased used. The 1 1/4 says "Orion Skyglow Ultrablock Japan", the 2" says "Orion Ultrablock Korea". The smaller seems a bit darker and a deeper blue when viewed flat on a white paper, the larger seems a little more transparent and appears to shade a bit toward turquoise. Anyone have any information about production history of the product line?

Jim

Jim,

I can't talk about history. However, my Orion Ultrablock also says "Ultrablock Skyglow" on the side. In fact the Ultrablock and the Skyglow are two different filters. ONe is broadband, the other narrow. One is blue the other more reddish. However, the way you describe them, you do have two of the "blues."

Aalex