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Dob users : Any words of encouragement?


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I currently have an old 4.5" Newt on an EQ mount, and I have been giving some serious thought into getting something a bit bigger and newer.

After much deliberation, I decided 8" is about the biggest size I would make good use of, but not on an EQ mount at the moment (would push the footprint/awkwardness up to much). So I'm pretty set on an 8" Dob at the mo' : SW200P f5.9 looking the favourite if I buy new.

But I really have a dilemma, I've never used a Dob mount, only an EQ.

I find the EQ mount very easy and straightforward to use, rough polar alignment, then swing to find, locate and then its a one handle twist to track - all pretty easy :o.

Well I was just out looking at Jupiter (between the clouds) and I pushed the mag up a bit to 150X (bit much for the scope but nevermind) and I had a nasty thought!!

If I get a Dob I have a feeling that it won't be anywhere near as easy

to track an object and change the mag up/down. At 150X it only took a few seconds for Jupiter to pass through the EP' FOV. I would be hoping to use some decent mag on the new Dob, (part of the reason for getting it) but how easy is it to actually use in practice.

Finding the targets doesn't worry me, it's the idea of having to track them and change up mags without losing the target and then having to re-aquire it by dropping mags, again I guess.

Guess I need some sage advice from Dob users, who could possibly reassure me about going through this change ie. EQ to Dob mount.

By the way: the plan is to hopefully mount the OTA onto a decent EQ mount sometime in the future (after having moved house).

Regards.

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Hi Orion, I had a 10" Dob (which I regret selling, but thats another story) and I never really found any trouble keeping planets in view, even at high magnification.

Like everything else theres a learning curve but you soon get used to the Dob mounts movements.

As for planets moving through the field of view of different eyepieces, i just moved the planet to one side of my field of vision, out of view, quickly changed eyepieces and let it drift back into view again, a quick focus adjustment and youre good to go.

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I have both mounts and the dob mount is far better to use. Very easy to set up and very easy to track with. Just a simple nudge to keep objrct in view.

If you place your object in the beginning of the fov and then change your eyepiece by the time you have done this it's notmally in the centre of your fov.

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..... and easy to put away after use.

Ron.:o

I have 3 castor wheels on the base of my dob, I wheel it out of the shed and can move it round the garden as required. Then wheel it back in afterwards. No setting up, just point and look.

Allan

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I have the Skywatcher 8" F/6 Dob and have been using it all week on Jupiter at x150 - it's very easy to track at this magnification. Did not go higher as seeing was poor.

I can also equatorial mount it and have used it at x343 on Jupiter when the seeing was good and it was a nice view.

Setup time is very quick indeed.

I put a fan in the back of mine and it really helps to move the boundary layer off the mirror giving steadier images.

This scope is very sharp and a really good buy.

You would have to spend thousands of pounds on a different design of scope just to match the 8" F/6 newtonian.

Clear skies.

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I would say a red dot finder/telrad is an absolute essential. I love my Dob. Dead easy set up and even my wife can use it (no she's not thick:eek:, just not as in to this as I am!) Point is a child could quickly learn to move it instead of struggling with slow motion the nobs I had on a 130 pm.

brian

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It's not a problem except near zenith
Whilst I agree, I'd like to point out that a good magnifying finder with some light grasp is helpful. 8x50 minimum. Those red dot & Telrad style finders just don't cut the mustard, though you may need one of those too for getting to the right general area of the sky if you are using a right angle finder.
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Thanks all for the feedback, feel a bit more assured its the right choice now :)

Will deffo be getting a Talrad or Rigel RDF to go along with the supplied 9x50 finder.

My current finder must be really poor, can only just make out the brightest of stars through it!

Does a SW 9x50 finder compare to the number of stars shown through 1 eye of a set of 10X50 bino's :o coz it it does, well WOW!

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Just to back up what the others have said, using a dob is simplicity itself. I've owned 8", 10" and now a 12" dobs and I've become a firm fan of them - Event the 12" can be got out fo the house and cooling just with a couple of quick carries, it's usable aroind 30 mins after it goes out but really sharpens up after an hour of cooling.

A 9x50 finder shows the same number of stars as 50 mm binoculars do - probably a few more because the prisms in binoculars will cause some light loss. Personally I find the red dot type finder (or 2 rings in my case as I use a Rigel Quickfinder) enough to find all but the most obscure DSO's.

The Rigel and Telrad finders are particularly good because they project rings with a specific angular diameter against the stars - very useful for star hopping !.

John

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I can recommend the book "Turn Left at Orion"

It shows you how to star hop to find 100 objects, shows you pictures of what you should be looking for, or, if you've found it, at, and also a good description of the object(s).

It will get you around the sky, invaluable with a Dob, and it even tells you what eyepieces work best.

Nothing worse than a new scope and no idea what to look at!

I have a problem using the finder so have bought a Telrad and fitted it to my Dob. I still use the finder on occasions, it sometimes seems to be getting easier!

Allan

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Dobs are a breeze to use and just fresh back from Kelling, I can report that with one exception, all the ultra deep DSO's I wanted were found in double quick time with a red dot finder + wide angle lens.

Of course, all the dob owners on SGL know that you have to keep "nudging" the scope if you want to centralise the object, but the best thing is to perhaps save up for some good quality EP's that work well with faster optics and then allow the object to drift in front of your eyes whilst you take in all that aperture !

With over 300 people at Kelling and kit on show to die for, I never felt more at home than with my Sky and Telescope Field Atlas, a RDF and the simplicity of the Dobsonian mount.

(of course... I still hanker after another scope but that's more out of due deference to lugging the scope out of the garage to watch the skies cloud over!)

Take the plunge ! - you will not regret it

Steve

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