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My Mistake

Roy@Aldermaston

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Roy@Aldermaston

Roy@Aldermaston

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I've just bought an Antares X0.5 focal reducer to use between my LX modded SP900 NC and the SW 200 PDS, but its impossible to get enough inward focus. Has anyone found a solution to this problem that doesn't involve moving mirrors, or similarly drastic measures.

Roy

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astro mick

astro mick

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Hi Roy.

I dont know how much inward travel you would need to attain focus,but an option(Although a little pricy) would be to change the Focusser to a Low Profile one.Several companies including Rother Valley Optics sell them.If you want to go down this route,i would discuss it with them as to suitabilty.

Other than that its moving the primary further up the tube.

Regards.

Mick.

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Roy@Aldermaston

Roy@Aldermaston

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Hello Mick,

Moving the mirror is the one thing that I wanted to avoid, but there may be an easier albeit more expensive way to solve this.

RVO sell these (http://www.rothervalleyoptics.co.uk/2in ... d2911.html) and used with one of these (http://www.teleskop-express.de/shop/pro ... wtons.html) it may be possible to increase the inward travel enough to reach focus - I hope.

If you have the time to look at the links let me know what you think.

Roy

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Roy@Aldermaston

Roy@Aldermaston

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Sorry for the duff links Mick, but in any case I've decided that this might do the trick for fewer pennies.

TS-Optics 2" to 1.25" telescope adaptor, 1.25" reducer: Amazon.co.uk: Electronics

I've checked the link and it seems to work.

In the meantime I've come across a work-around which involves unscrewing the 1.25" barrel from the 2" threaded adapter and refitting it the other way round, so that it extends into the focuser rather than extending outwards. The only disadvantage is that the thumb screws on the 1.25" barrel can't be used to secure the camera nose piece, so I'll need a cable tie to stop the camera from flopping around, but it will do as a stop-gap.

I'll try it out tonight.

Roy

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Roy@Aldermaston

Roy@Aldermaston

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The trick to get more inward focus travel worked perfectly with the SP900NC and X0.5 reducer. Plenty of travel in both directions. My description of the mod was too confusing so I've added a PDF file with pictures.

I can't take credit for the method and pictures, which were posted on another site. I don't remember who first came up with the idea, but I'm very grateful and hopefully the author won't object to my posting it here.

Roy

Skywatcher Inward Travel Mod.pdf

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Roy@Aldermaston

Roy@Aldermaston

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Thanks Jake,

What I was was trying to do by using the focal reducer was get a slightly larger field of view, partly to make it easier to frame the object. The method that I described was only a temporary fix while I am waiting for a low-profile 2" to 1.25" adapter to arrive.

Roy

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jnc71106

jnc71106

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How clear are the skies around Basingstoke, we get a lot of LP from Newbury, Reading and AWE.

Roy

From my garden north is not great because of the town centre. Can barely make out Polaris most nights

but it's not to bad overall really

Tried to convince the OH to move to sark but she won't have it ;)

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