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Message: <blockquote data-quote="steve johnson" data-source="post: 298285" data-attributes="member: 15465"><p>Chartwell99 is right.  I should have looked at my reference materials a bit more before answering.  One element of an Uppendahl prism is a roof prism and does rely on reflection.  I would note however, I took these out and compared them with a 5 year old pair of 8x32 BN and I have a very hard time seeing any difference in contrast or clarity.  When I looked through a 40 year old pair of 6x24 however there is considerable softness to the image and the brightness does not equal the later trinovid or the BN.  I suspect the coatings improved considerably during the 27 years the trinovid models were in production.  I have also found that in general the Portugal models seem sharper than the German, although some models, in particular the wide angle 8x32 were only made in Germany.  I don't know what market Leitz intended for these glasses.  However they were available from 1965 until 1990 - longer than many other models such as the 7x42 or the 8x40.  The 7x35BA were only in productoin for 3 years, making them among the more rare trinovid models.</p></blockquote><p></p>