compassrose Posted July 18, 2012 Share Posted July 18, 2012 Hi all.Anyone know why the lens cap on my 4" skywatcher short tube refractor has a removable centre portion - is it something to do with using the centre, more optically correct part of the lens? If so, when would be an appropriate time to use it?CheersDavid Link to comment Share on other sites More sharing options...
seigfriedwilson Posted July 18, 2012 Share Posted July 18, 2012 Hello,You can use it to stop down the apature when looking at bright objects, such as the full moon.Some ccds can be used with it to help improve focus as well.Seigfried Link to comment Share on other sites More sharing options...
compassrose Posted July 18, 2012 Author Share Posted July 18, 2012 Thanks. Link to comment Share on other sites More sharing options...
cotterless45 Posted July 18, 2012 Share Posted July 18, 2012 It's also good for splitting doubles,Nick. Link to comment Share on other sites More sharing options...
compassrose Posted July 18, 2012 Author Share Posted July 18, 2012 Thats interesting Cotterless45, can you elaborate for the sake of a complete newbie? Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.