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firephinix

Best ask in here then lol

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Hi

I got a celestron 130eq-md for Christmas and so far iv had very good views of the mood and Jupiter.

I bought myself the celestron eye peice kit that comes with a 2x Barlow lens, a 6mm, 15mm eye pieces and some filters.

Now for the questions. If I use the Barlow and the 6mm it gives me a 3mm but I can't focus enough to get a better view, could I move the balow and eye peice out a bit more to get in focus or could I get a extension tube to focus more? (if any of that makes sense)

Would a 3x Barlow be any use?

Would like to use a webcam, I have ordered an adapter tube for it onto the telescope. Do I just put it into the focuser or do I need to put it into the barlow? Also want to use my camera but iv tried the film case onto my camera (which fits really well) but when I put it into the Barlow and the focuser I can't see anything even though with eye piece can see what I'm looking at. Iv looked at so many tuts Im lost lol. So any help would be appreciated and in a newbe/plain english way as tech speak I can't understand yet lol

Hope you can help as hae asked else where and they didnt exactly answer the questions lol

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Not sure of the focal length of your scope but I'm wondering whether a 3mm ep might be too much magnification if the seeing isn't great.

just a thought

Scott

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far too much you need a ed80 or something to handle that power id say a 8mm unbarlowed is your highest power

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For any given telescope, often the practical magnification limit is often 150x or so - and occasionally as little as 100x or 125x. That has more to do with the atmosphere over your head than the telescope next to your feet. That said, the atmosphere can - and sometimes does - cooperate more. When it does, the stars will not "twinkle" as much, and appear steady. On those nights, you can often push the magnification higher.

For your scope (which appears to be a 650mm focal length instrument), the maximum practical magnification is about 250x. That's the best you're going to do on the very best nights, which might happen once or twice a year (well, at least near me). More often, you'll achieve somewhere in-between that 150x and 250x. For that, the barlowed 6mm at 2x is going to be okay. But again, on GOOD nights of seeing. The other problem is cooling - the atmosphere may be steady, but if your mirror is releasing heat into the tube because it was indoors and you go outside with it where the temp is much cooler, the image at the eyepiece will be less than perfect. Until your mirror finishes (or is closer to) contracting fully, it will also alter the image that can be focused.

For practical viewing purposes, I think you would be well-served to have an 8mm eyepiece, and barlow it to achieve 150x on most nights. It will also give you medium power views un-barlowed at around 75x.

Hope that helps.

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yeah i keep my scope out in the garage as my tech head took over and thought to myself going from warm to cold isnt good thus it being in the garage. thanks for the info of the ep guess iv just gotta have a play around when wev got clear nights

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The focal length of the scope you have is 650mm. By using a 6mm EP and a 2x barlow, you are pushing the scope beyond what it is able to do. This combo is giving you a magnification of about 220x...................way too much. For a scope with a focal length of 650mm, the highest magnification you can expect is between 100-150x. If the weather in the UK was better then you might be able to get about 200x out of it, but that is a rare thing in this part of the world.

Edited by LukeSkywatcher

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I have that scope too & agree with everything above. My highest power ep is 8mm and on a few occasions I have barlowed it, but often this really degrades the image if the seeing is not so good. 8mm is good though, but my fave is a 15mm ep giving 43.5x magnification, not much but good for DSOs

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Hijust read your post

Re tha webcam I just put mine straight into the eyepiece holder without the eyepiece or a barlow and get good results from that hope this helps

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