Sponsored By:

Subject: Re2: Re2: F6.3 reducer formula
From: DK0179@AppleLink.Apple.COM
Reply To: mapug@shore.net
Date: Sat Jul 22 01:06:00 1995

Tom, Thanks for your letter , I will order that book on the library. ---------------------------------------------------------------------------- <" The focal length of the telescope-focal reducer combination is f of the <telescope times the magnification of the focal reducer." I am however not sure what the magnification of the focal reducer means. Usually magnification requires that you have the focal plane IN FRONT of your lens. In example, a stamp collector puts his stamp IN FRONT of the lens. This is also the case when you do eyepiece projection, and here your formula is straightforward understood. But in our case, there is NO IMAGE, no focal plane in front of the lens, so it is not easy understanding what this focal reducer case magnification means. There is however no doubt, that magnification (similar to the magnification of a stamp collectors magnifying glass) is depending on the distance, we thus have indeed a distance dependence. So, again, the critical question is, WHAT IS THE IDEAL DISTANCE FROM THE f 6.3 FOCAL REDUCER TO THE FILM PLANE ? Anyone having data ? Best greetings, Mogens.