Review on Eisco Right Angled Glass Prisms by Josh Maher

Two stars for poor optical quality. I assumed that a manufacturer with the word "Laboratories" in the title produces according to the visual optics standard. I was planning on using it in the viewfinder but it's not good enough due to the severe orange peel burnish on the working edges - the images viewed through the prism are distorted and very blurry. I wish I had looked more closely at the pictures in the product description as they show a polishing flaw. However, if you need a prism to spread light across the spectrum then that's fine.