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Barlow lens with. 965 screw thread?


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Hi, my 3 inch spotter has a short focal length, 380mm and the eyepiece gives 27x. I wrote to the manufacturer some years ago (Opticron) asking about the possibility of getting higher magnification but they informed me that if I wanted 100x magnification, because the eyepiece would be very short in focal length I wouldn't be able to get infinity focus. I have sort of confirmed this by taking the 4mm eyepiece from my daughter's Firstscope and holding it inside the eyepiece hole. Very blurry, it's short sighted.

But I was informed on a Facebook astronomy group that a Barlow would work because it effectively doubles the focal length of the scope, so my 27x eyepiece would give me 54x, which is better for planetary viewing.

There's just one problem, the fitting. My scope, being a terrestrial scope, has a screw fit eyepiece mount of the old. 965 thread, and astro lenses are drop in. Is it possible to find a Barlow with such a thread?

Or some other way of magnifying the image?

Thanks.

Larry

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You can buy adapters, I believe, but I'm not sure where from (Google may help?).  The alternative is to buy a 1.25" focusser (or 2") and replace the one on the scope.  New they can cost a bit but you could probably get one second hand from AstroBuySell or similar as many folk update their focussers and therefore have their own originals to sell.

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You can buy adapters, I believe, but I'm not sure where from (Google may help?).  The alternative is to buy a 1.25" focusser (or 2") and replace the one on the scope.  New they can cost a bit but you could probably get one second hand from AstroBuySell or similar as many folk update their focussers and therefore have their own originals to sell.

The focuser can't be removed, or at least not by me. It's not as astro scope and I think the focuser is of the helical type? All built in to the scope's body.

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I've got a 1.25" to 0.965 adapter, like this, but it doesn't have a threaded end:

http://www.ebay.co.uk/itm/NEW-Well-Built-1-25-to-0-965-Eyepiece-Convertor-Adaptor-for-Telescope-/201076295492?hash=item2ed114c744

Are you essentially after something like this but with the 0.965 male end threaded?

James

Hmm it needs to be threaded at both ends, but really a Barlow lens with. 965 threads at both ends would help. The only 1.25 eyepieces I have are my daughter's 20mm and 4mm, but they're poor quality. The 4 mm is just a single lens, and the 20mm would reduce magnification.
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I have never come across a 0.965" THREADED focusser on astronomical telescopes, but that is not to say that they do not exist. The usual ( older ) fittings are the 0.965" push fit and 1 1/4" RAS threaded ( aka 1 1/4" BSP ). I suspect that the one you have is a manufacturer specific for that 'scope and apart from making your own adaptor/barlow combo you will not be able to use anything other than the supplied eyepiece(s).

Nigel

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