The Starfinder EQs

<body topmargin=0 leftmargin=0 marginheight=0 marginwidth=0> <table cellpadding=0 cellspacing=0 border=0><tr> <td valign="top" colspan=2 height=90 BGCOLOR="#006699" TEXT="#080000" bgproperties="fixed" background="015285a1erlcgo.gif"> <div> <FONT SIZE="3" COLOR="#FFCC66" FACE="Arial" ><B>N.T.L. - The Starfinders' Home          </B></FONT><A HREF="http://astronomie.n-t-l.de" TARGET="_top" TITLE="http://astronomie.n-t-l.de"><U><B>To NTL-AstroHome</B></U></A><B>     </B><A HREF="http://www.n-t-l.de" TARGET="_top" TITLE="http://www.n-t-l.de"><U><B>To  NTL-Homepage</B></U></A></div> <bR> <div> <A HREF="starfinder_types.htm" TARGET="_top" TITLE="Overwiew of Types"><U>Overwiew of Types</U></A>   |   <B>The Starfinder EQs</B>   |   <A HREF="starfinder_faq_eng.htm" TARGET="_top" TITLE="The StarfinderFAQ"><U>The Starfinder-FAQ</U></A></div> <div> </div> </td> </tr><tr> <td valign="top" width=150 BGCOLOR="#FFCC66" TEXT="#080000" background="013d4c00dkelyh.gif"> <bR> <div> <B>Overview of Types</B></div> <bR> <div> <B><U>The Starfinder EQs</U></B><FONT SIZE="3" COLOR="#003399" FACE="Wingdings" >ü</FONT></div> <bR> <div> <B>     </B><A HREF="sf1_eng.htm" TARGET="_top" TITLE="The SF1"><U><B>The SF1</B></U></A></div> <bR> <div> <B><U>NEW!</U></B></div> <div> <A HREF="ra_drive_eng.htm" TARGET="_top" TITLE="The RA Drive"><U><B>The</B></U></A></div> <div> <A HREF="ra_drive_eng.htm" TARGET="_top" TITLE="The RA Drive"><U><B>RA-Drive</B></U></A></div> <bR> <div> <A HREF="photosetup_eng.htm" TARGET="_top" TITLE="The Photo SetUp"><U><B>Astro Photography</B></U></A></div> <bR> <div> <A HREF="tubestraps_eng.htm" TARGET="_top" TITLE="The Tube Straps"><U><B>Stabilizing the </B></U></A></div> <div> <A HREF="tubestraps_eng.htm" TARGET="_top" TITLE="The Tube Straps"><U><B>tube straps</B></U></A></div> <bR> <div> <B>The Dobsonians</B></div> <bR> <div> <B>The Starfinder-FAQ</B></div> <bR> <div> <A HREF="starfinder_eng.htm" TARGET="_top" TITLE="Starfinder_eng"><U><B>back</B></U></A></div> </td> <td valign="top" height=390 BGCOLOR="#000066" TEXT="#F7F7FF"> <bR> <div> <I><B>The equatorially mounted Starfinders</B></I></div> <bR> <bR> <div> In my opinion, the equatorially mounted Starfinders are the most interesting memebers</div> <div> of this family, because they combine the possibilities which come with a rock solid</div> <div> German equatorial mount and the optical possibilities of splendid aperture of not less</div> <div> then 6 inches! And all this for an affordable and reasonable price!</div> <div> The SF1 is dimensioned to carry the 10-inch tube with 1140mm (45inches) focal length</div> <div> (1150mm tube length and 34cm tube diameter) without any problems. The 8- and 6-inch </div> <div> tubes should be carried with additional equipment!</div> <div> My own SF1 carries a 130/900-Newtonian and a 70/700-Refractor for photographic purpose</div> <div> with ease, for this equipment, the counterweight wich came with hte 10-inch tube is</div> <div> definitely too heavy, also, if it is in the innermoust position of the Dec-Axis! On the other</div> <div> hand, the 10-inch tube with a guider-scope would only be applicable under the condition</div> <div> of absolutely no wind! More about this in the section Astro Photography.</div> <bR> <div> <U>The outfit</U></div> <bR> <div> The Starfinders EQ come with the mount including a quartz controlled tracking</div> <div> motor and the matched counterweight. They also have an achromatic 6x30mm-</div> <div> <B>finderscope</B> in two three-point-bearings which can be very well adjusted. The</div> <div> finderscope's crosshair is quite thick which looks a bit strong at the first glance.</div> <div> However, in practical use, the thick crosshair is quite obvious even under dark</div> <div> skies, a real advantage over finders with thin crosshairs. The finder can be</div> <div> focussed.</div> <div> The <B>primary mirror</B> is, of course, a real parabolic mirror, not only a spherical one.</div> <div> The over all quality of the Starfinder mirrors is quite good, I have never heard of</div> <div> a bad one. They're made of Pyrex, not plate-glass, so that thermal expansion </div> <div> isn't of any significance. The Aluminium lies under a quartz coating.</div> <div> The <B>mirror cell</B> is an open one machined from aluminium so that the mirror</div> <div> can come to a thermal equilibrium in quite a short time. The 6-, 8- and 10-inch</div> <div> mirrors have a three point cell, the much bigger 16 inch has a nine-point mirror cell.</div> <div> The mirror cell can be adjusted very precisely due to extremely massive pairs</div> <div> of screws.</div> <div> The <B>secondary</B> is fixed with a minimum of obstruction: the mirror is clipped to a</div> <div> elliptical piece of metal fixed with a four-arm spider made from steel ribbon so</div> <div> that the spider and vane don't induce any further obstruction.</div> <div> The only disadvantage is, that the screws for adjusting the secondary are a bit </div> <div> fumsy to reach. One of them is quite good to reach, the other two are hidden</div> <div> by the spider's arms, so one must put in the screwdriver a bit obliquely.</div> <div> The workaround to fix this I did, was to cut a bit of the shorter side of the tool.</div> <div> The <B>focusser</B> is the worst thing coming with a Starfinder. It is 2inch with a </div> <div> reduction to 1.25" and T2-winding, but it focusses very rough and unprecisely!</div> <div> The tolerances of the focuser are, simply spoken, too big, much too big.</div> <div> The best thing would be, to replace this part by a real focusser.</div> <div> The <B>26mm-Superplossl eyepiece</B>, shipped with the Starfinders, is an excellent</div> <div> eyepiece with very good sharpness to the edge of the visible field, which extends</div> <div> to 52 degrees. The contrast of this eyepiece is very good and I have never seen</div> <div> any reflexions in this eyepiece.</div> <div> In one word, You could say, the Starfinders are quite serious scopes and they are</div> <div> recommendable. They have their little weaknesses, but not more than any other</div> <div> scope of any other manufacturer would have.</div> <bR> </td> </tr></table></body>