Archived posting to the Leica Users Group, 1997/07/09
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]Jim, I have a loupe test on file, proposed by Rodenstocks B. Saloman as a good way to judge a loupes performance. Excerpted below: >>If you want to evaluate loupes there is a very easy test. Draw 2 crosses on a piece of paper. Make the length of each line 2". Place a loupe on the center of the cross and first look into the eyepiece with your eye appx. 10 to 12" above the eyepiece and see what happens to the lines. A highly corrected loupe will have straight lines. the worse the correction the more curved the line will appear. Loupes with very poor correction will actually make circles out of the end of the lines. Next put your eye against the eyepiece and move your eye left to right along the line or up and down along the line. With a really good loupe there will be no movement of the lines. A Rodenstock 4x Aspheric easily passes this test. Very few other loupes can. Bob Bob Salomon, HP Marketing Corp.<<