Barlow problems

[ZOG]

The sky actually cleared for a while last night so I dragged the scope out with the intention of trying out the new barlow which is a CelestronX-cel ED and is reckoned to be a decent quality barlow. I tried it first with the Meade 4000 series 32mm. It would only just come into focus in the 300p focuser on the moon but when I swung the scope round, the stars were slightly out of focus.

I then tried a variety of othe EP's from 25mm down to 5mm and the scope wouldn't come to focus with any of them. It seems that there isn't enough in travel on the 300p focuser for this barlow.

Has anyone had (and solved) this problem, or is it a case of putting the barlow on the shelf until I can afford a replacement focuser.

On an aside, the scope without the barlow performed really well. M42 trap stars were the best I've seen them although strangely the nebula wasn't as well defined as it was the last time I observed it, but the seeing wasn't that good and the finder and EP's all dewed up fairly quickly.

[ash]

Hi ZOG, have you tried moving the barlow out of the focuser slightly then try a re-focus i have the same problem with my st80 as my barlow is quite long and it works fine HTH.

Andy

[ZOG]

Ash, yes I tried that but that takes the barlow away from focus ie the opposite of what I need. It looks like the travel on the focuser isn't enough to get the barlow close enough to the secondary.

[John]

This seems to be a common issue with barlow lenses - they require some additional "in-travel" to come to focus. I had the same problem with my Skywatcher 200P and an Antares 1.6x 2 inch barlow recently which was a shame because otherwise it's a lovely bit of kit . I had to sell it in the end and use shorter focal length eyepieces instead.

John

[ZOG]

Yeah it seems a shame John. I think rather than sell the barlow, I'll keep hold until I upgrade to a new focuser and see how it works then. I'm looking at either the new Skywatcher low profile focuser, or if I'm feeling flush, a moonlight

[Astro_Baby]

I had a similar problem with a Celestron Barlow on the SW-200 - my problem though was that it wouldt come out far enough. I just used the barlow slightly pulled out from the scope.

I'm currently sufeering sismilar problems with a 2" Barlow - I have a tube extender which I'll try when I get some spare time.