Using the 2" ED Barlow on SW200P DS

[dlp]

Recently bought above Barlow and am having some problems! To get to focus I am having to extend the barlow almost fully from the 2" telescope focuser with my standard 28mm ep (fitted to its extension tube also). This must put a huge strain on the focuser assembly. I tried fitting my DSLR to this shaky setup but could not get focus. Has anyone else encountered these problems, or am I doing something incredibly stupid? (likely!)

Disgruntled David

[dlp]

Perhaps a picture would be more useful...

[Bizibilder]

You shouldn't need the extension tube? Are you sure it won't focus without it? The focus will be different from the position with no Barlow but not that far.

[dlp]

I'll retry that later on when I've got something far enough away to focus on! I seem to recall the extension tube was necessary.

[TheThing]

Is the picture just representational? Only the focuser doesn't seem too far out TBH. Even at full stretch, it sould be ok.

[Chris H]

I'll retry that later on when I've got something far enough away to focus on! I seem to recall the extension tube was necessary.

Have you tried this on the night sky or on a distant object during the day? If it's during the day you won't be focusing on infinity and you might find the set up works on stars.

[dlp]

I tried this again last night and found I can dispense with the extension tube for the 28mm. The Barlow is only inserted into the focuser about 1" though which to me seems bad design (or maybe just the laws of physics!). At the least the telescope should have a compression ring fixing on the focuser rather than just a couple of thumbscrews - what's the chance of something staying straight with just those to hold it?

[Bizibilder]

The "as supplied" focusser just has the two screws to hold things - often this is the case with most manufacturers! If you upgrade the focusser (expensive, of course!) you can get a compression ring and a much more secure system - you pays your money.......

[dlp]

I'm beginning to find this is not a cheap hobby. I hear Moonlight gently calling...

[Bizibilder]

This is why we all like spending OTHER peoples money!! Join the club!!