Earthwin optical path length ?
Posted 08 May 2013 - 04:22 PM
Posted 08 May 2013 - 10:23 PM
Install the BV in the daytime, and place a piece of tissue paper inside one of the barrels, up against the prism opening. Focus some object onto the paper; the target need not lie at infinity. Measure the distance from some convenient surface at the scope's back end. Remove the BV--but do not touch the primary mirror focus--and find the new focus position and measure the distance, using the same reference surface as before. The difference in distances is the optical path length required for the BV.
Posted 09 May 2013 - 12:50 AM
My problem is I have the bino but it is in my obs which is 500 miles away from me right now Saturday I will be there but then it will be a bit late for ordering the stuff which needs to be in Wisconsin latest by next saturday for me to pick up during my stay there
Anyway, let's see if any friends here or Bill at Earthwin can give me this info earlier than Saturday. I've sent an email to Bill as well.
Posted 09 May 2013 - 07:17 AM