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Semi-Apo

Started by sjs42, 09/19/2005 12:50AM
Posted 09/19/2005 12:50AM Opening Post
The much used semi-Apo term seems to have little concrete meaning when viewing other than "better than our regular achromatics." Please see discussions on the Refractor forum. I see semi-Apo binoculars advertised. What are these supposed to be?
Posted 09/19/2005 12:28PM #1
I think the meaning is about the same. I am familiar with
the Apogee RA-88-SA which are supposedly "Semi-APO" and have
triplet objective lenses. They show less false
color than an achromatic doublet, but still alot more
than say a Fluorite APO doublet.