Help!! My Schmidt-Cassegrain All Screwed Up.

[emperor_of_localgroup]

<p>&nbsp;<font size="2">I looked at the currently bright Jupiter in the sky with a 4.5" Refractor and a Schmidt-Cassegrain Nexstar 8i Reflector. The refractor's view is good to excellent but my reflector's view is all messed up and all I see a long thick continuous line. I have roughly made a free-hand sketch of what I see through each telescope, see below. Not drawn to actual size and view.<br /></font></p><p><br /> <img src="http://sitelife.space.com/ver1.0/Content/images/store/10/4/cab5bc22-e7cb-41f2-8409-f1a13b05924e.Medium.jpg" alt="" /><br />&nbsp;</p><p><font size="2">As you can see the 8" reflector is not showing a correct&nbsp; image. What have gone wrong with my scope? Is it the mirror? Is it fixable?&nbsp; I know telescope theory somewhat but never played with telescope interior. Any advice will be more than welcome. </font></p> <div class="Discussion_UserSignature"> <font size="2" color="#ff0000"><strong>Earth is Boring</strong></font> </div>

 

[crazyeddie]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>&nbsp;I looked at the currently bright Jupiter in the sky with a 4.5" Refractor and a Schmidt-Cassegrain Nexstar 8i Reflector. The refractor's view is good to excellent but my reflector's view is all messed up and all I see a long thick continuous line. I have roughly made a free-hand sketch of what I see through each telescope, see below. Not drawn to actual size and view. &nbsp;As you can see the 8" reflector is not showing a correct&nbsp; image. What have gone wrong with my scope? Is it the mirror? Is it fixable?&nbsp; I know telescope theory somewhat but never played with telescope interior. Any advice will be more than welcome. <br /> Posted by emperor_of_localgroup</DIV></p><p>There could be several things wrong. &nbsp;It could be out of collimation (but the way you drew the image, I'm inclined to think this isn't the problem). &nbsp;Was the scope sufficiently cooled down before you started observing? &nbsp;Schmidt-cassegrains are VERY sensitive to temperature swings and must be set out at least an hour before you begin observing to let it's temperature equalize to ambient.....especially when taking it from a warm house into cold night air. Is everything OK with the eyepieces you are using and the diagonal? &nbsp;Try using them in the refractor to see if the problem repeats itself with the other instrument. &nbsp;If it's not the collimation and it's well-cooled-down, I'm not sure what could have brought this on suddenly....did you bump it or did it get shaken around in the trunk of a car? &nbsp;Whatever you do, don't try disassembling anything and poking around inside a SC....that's a job for experts. &nbsp;if you dealer is nearby, they might be able to diagnose the problem.</p> <div class="Discussion_UserSignature"> </div>