http://tech.groups.yahoo.com/group/schupmann/ Schupmann Thu, 03 Dec 2009 18:50:35 GMT David http://tech.groups.yahoo.com/group/schupmann/message/1164 http://tech.groups.yahoo.com/group/schupmann/message/1164 John, Schupmann optics are pretty rare. I only know of two set that have exchanged hands in the last 10 years. I would guess that a commerical shop would Thu, 03 Dec 2009 09:01:34 GMT johnny999_99 http://tech.groups.yahoo.com/group/schupmann/message/1163 http://tech.groups.yahoo.com/group/schupmann/message/1163 Hello, Does anyone know of opticians who are amenable to making a Schupmann optics set, or if there are complete telescopes for sale? Thanks John Wed, 02 Dec 2009 00:13:06 GMT James A. Daley http://tech.groups.yahoo.com/group/schupmann/message/1162 http://tech.groups.yahoo.com/group/schupmann/message/1162 Hi John, The thickness of a Schupmann objective is not optically critical but if too thin it will be overly flexible and could lead to polishing and figuring Tue, 01 Dec 2009 03:00:47 GMT johnny999_99 http://tech.groups.yahoo.com/group/schupmann/message/1161 http://tech.groups.yahoo.com/group/schupmann/message/1161 In a circa 2007 thread, there was a reference to a Schupmann in Canada. Since I am there (here, in Toronto) most of the time - does anyone know where it is? Mon, 30 Nov 2009 20:27:51 GMT johnny999_99 http://tech.groups.yahoo.com/group/schupmann/message/1160 http://tech.groups.yahoo.com/group/schupmann/message/1160 Thanks guys - I will keep my eyes peeled for BK-7 or BSC-2 blanks. No need to be penny wise and pound foolish. What range of thicknesses would match up for Mon, 30 Nov 2009 14:55:31 GMT David M Groski http://tech.groups.yahoo.com/group/schupmann/message/1159 http://tech.groups.yahoo.com/group/schupmann/message/1159 Hi John, With OSLO and knowing the RI of the flint I'm sure one can come up with acceptable design. Personally I would keep my eyes open for BK-7 or BSC-2, Mon, 30 Nov 2009 14:54:13 GMT James A. Daley http://tech.groups.yahoo.com/group/schupmann/message/1158 http://tech.groups.yahoo.com/group/schupmann/message/1158 Hi John, A Schupmann medial can be made with flint glass but be sure it is objective grade. If I remember correctly, one interesting feature of a flint Mon, 30 Nov 2009 03:16:47 GMT johnny999_99 http://tech.groups.yahoo.com/group/schupmann/message/1157 http://tech.groups.yahoo.com/group/schupmann/message/1157 I ask only because there appear to be decent, relatively cheap flint blanks on ebay. How much is a 9" BK7 blank? Mon, 30 Nov 2009 01:54:18 GMT Arnold Ashcraft http://tech.groups.yahoo.com/group/schupmann/message/1156 http://tech.groups.yahoo.com/group/schupmann/message/1156 John: I am sure you could come up with a usable design based on any optically homogenous glass with low color and high transparency, but I don't think there Mon, 30 Nov 2009 01:28:02 GMT RAYMOND REIFFER http://tech.groups.yahoo.com/group/schupmann/message/1155 http://tech.groups.yahoo.com/group/schupmann/message/1155 Hi John well my answer may not be of any value because I have never made a schupmann of Flint, but it seems to me that it would be no problem except that Mon, 30 Nov 2009 00:27:39 GMT johnny999_99 http://tech.groups.yahoo.com/group/schupmann/message/1154 http://tech.groups.yahoo.com/group/schupmann/message/1154 Hello, I know a few of the folks here.... My copy of the Daley book is in storage at the moment and I had a burning question. Are flint glasses an option for Sat, 07 Nov 2009 18:40:15 GMT marcething http://tech.groups.yahoo.com/group/schupmann/message/1153 http://tech.groups.yahoo.com/group/schupmann/message/1153 Thanks a lot Dave !! You're the man :-) Fri, 06 Nov 2009 18:54:12 GMT Arnold Ashcraft http://tech.groups.yahoo.com/group/schupmann/message/1152 http://tech.groups.yahoo.com/group/schupmann/message/1152 Veery eeenteresting Dave! Looks like you managed to dispense with the auxiliary surface 3 with air after it. I will have to study this. Clif Fri, 06 Nov 2009 18:35:22 GMT David http://tech.groups.yahoo.com/group/schupmann/message/1151 http://tech.groups.yahoo.com/group/schupmann/message/1151 Hi All, I figured out away to enter a folded Schupmann similar to what Gerry Login did for his larger Schupmann as pictured in Mr Daley's book, into OSLO.EDU. Wed, 04 Nov 2009 19:44:44 GMT David http://tech.groups.yahoo.com/group/schupmann/message/1150 http://tech.groups.yahoo.com/group/schupmann/message/1150 Hi Marc, I was playing around with adding the flat into the OSLO file last night but ran into the 10 surface limit in OSLO EDU. I'll see if I can come up with