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Boo

Celestron NexStar 6SE - a beginner struggles....

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Hello!  Another newbie here with some telescope related questions.  It's entirely possible that these have been answered elsewhere on the site, but given that we're on holiday in the wilds of deepest Cornwall, with no wi-fi, and an iPad that's clinging on to the last scraps of a 3G signal (I'm standing outside waving it about in order to post this), I'm hoping you'll forgive me if I just plough on and ask my dumb questions.

A bit of background.

Yes, we should have done a pile of research before going ahead and spending our hard earned cash, but after two years of talking about buying something, my wife and I had a moment of madness, took a trip to a Telescope shop in Dorking (not sure if it's the done thing to name names or not, but a) I'm sure most people can figure out where it is, and B) I've got nothing but praise for them anyway) and after a long chat, came out having ordered a Celestron NexStar 6SE.

It duly arrived a couple of weeks later, we unpacked it, we stared at it uncomprehendingly and packed it away again.

We watched a few 'setup' videos on Youtube and then a few days after that, packed it in the car to go on holiday to Cornwall, where we knew dark skies awaited.

Which is where we are now.

We'd figure it out in two weeks?  Right?  Hmmm.

First up - finderscope.  Now I have found a couple of things related to this, and they all seem to suggest aligning it on a distant telegraph pole or similar.  I've tried this, and there is absolutely no way that there's enough adustment in the finderscope to allow this.  And I'm not surprised.  If we assume that the nearest thing we're going to look at is the moon, which is what, quarter of a million miles away?  Then in that case, the telescope and the finderscope will be near as dammit parallel.  To try and align it on something three miles away will be like trying to get both of your eyes to stare at something halfway up your nose.  Simple geometry says it's too close.

For now, we're managing without it, and as soon as the moon puts in an appearance, I shall use that to align it.

If I've made some ridiculous newbie error by assuming something incorrectly (as my Mother-In-Law says, to assume just makes an ass out of u and me), then please dive in and correct me!

Secondly (and this is going to sound dumb, but hear me out), I'm not sure if I'm setting the time correctly.

My reasoning goes like this.

It's currently summer in the UK, so we're on BST.  The Celestron doesn't have either GMT or BST, but does have something called Universal Time.  I'm assuming (sorry!), that Universal Time = GMT.

Now, let's say it's 10pm BST, and I'm setting up the scope.

I put the time in as Universal Time.

I put the time in as 22:00

I accepted / pressed enter for Daylight Savings.

My thinking was 'I've said it's 10pm, and I've said that it's Daylight Savings, so the scope will know that it's really 9pm Universal Time.'

After that, I thought 'Maybe, if I've said that it's Universal time (which is GMT), I should have put the time in as 9pm, and then when I accepted Daylight Savings, the scope would know that it's really 10pm.'

As you can see, I've managed to baffle myself completely.

Anyway, we have another few days down here, and the skies have been fantastic, so if any of you fine people can help out a bumbling noob, then I'd be most grateful indeed.

Thanks very much!

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Hi Boo, welome to SGL.

quote: "First up - finderscope. Now I have found a couple of things related to this, and they all seem to suggest aligning it on a distant telegraph pole or similar. I've tried this, and there is absolutely no way that there's enough adustment in the finderscope to allow this. And I'm not surprised. If we assume that the nearest thing we're going to look at is the moon, which is what, quarter of a million miles away? Then in that case, the telescope and the finderscope will be near as dammit parallel. To try and align it on something three miles away will be like trying to get both of your eyes to stare at something halfway up your nose. Simple geometry says it's too close."

Have you adjusted all the bolts on the finder bracket? It just needs a little patience to get the finderscope parrallel with what you see in the eyepice of the OTA. That said though, if you are planning and taking the scope out and about then (other than the garden) it will need a minor tweek to ensure that it is parrallel everytime. I have the C6-SCT/XLT and I have to do it everytime. It passes the time while wating for the OTA to become ambient/cool.

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Using UTC and specifying DST and then enter whatever time it is works on my 8" Celestron SCT.

I'm not quite sure understand your finder scope problem but a few hundred yards in daylight is usually good enough. Like Phil says you need to adjust the three bolts/screws holding it in place.

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Re the finder scope, I had this issue too. I made up a small shim from a business card and inserted it underneath the mounting plate between the two screws and it worked. I had enough adjustment.

Once this was done I used the moon centre as a first set aliging step for the finder scope as it is a nice fat target. Once I did that I set it up using a star and a low power eye piece.

http://www.timeanddate.com/worldclock/results.html?query=plymouth+england try this for Universal time.

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I disagree on your summation re the finderscope I've had a 4se and a 8se. With both I started by aligning (during the day) on next doors chimney then moved further to a tree three miles away and finally checked on the telegraph poles 15 miles away on the horizon. In both cases this took a little while but was possible and meant it was spot on when using at night.

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Many thanks for all the replies. I shall persevere with the finderscope, and dig out the screwdriver if necessary.

Cheers, gkec, for the comment about the time.

Looks like we'll have clear skies tonight, so I shall have another crack. If I've understood correctly, then, assuming a setup time of 10pm (BST), I'll need to :

Set time to Universal, which equates to GMT.

Set clock to 21:00 (as 10pm BST = 9pm GMT).

Select Daylight Savings.

Thanks again, one and all.

Boo

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NO! If you adjust from what your watch says and also click daylight saving you will have adjusted twice! Put the time from your watch (or better still from your phone) and then click daylight saving. Remember the date format is american so month first then day then year.

Its a cracking scope and mount and you'll have loads of fun with it once you've got to know it a bit better :-) There is a site dedicated to all things nexstar http://www.nexstarsite.com/ My SE mount has had much more use than my bigger mounts purely because of its ease of use.

Have Fun!

Helen

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Well, I'm definitely doing something wrong. Could be the time, or maybe I've messed up the Long / Lat. Either way, the three-point Skyalign said it had worked and then was most certainly not pointing at what it said it was.

I shall go back to basics tomorrow - thank you for the correction about the time, Helen.

However, by luck or by judgement, we found Saturn.

Wow...

I've seen countless pictures of it, but to see it with your own eyes (sort of) - and as clear as a bell - is mind boggling.

I can see why people get hooked on this!

Boo

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Saturn is awesome!!

Helen

PS Try again tomorrow, but come back if it doesn't work, we can try and track down the source of the problem. By the way you're not using normal batteries are you? That can cause all sorts of problems. You need a powerpack or mains supply really.

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Do as Helen says! As for the alignment, try 2 star or even align just on Saturn to start with. For the 3 star alignment you need to make sure that the stars are in the alignment list. Go to on the NexStar Resource site for a useful little program which will give you the best stars to choose for any time, date and place.

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Many thanks for all the replies. I shall persevere with the finderscope, and dig out the screwdriver if necessary.

Cheers, gkec, for the comment about the time.

Looks like we'll have clear skies tonight, so I shall have another crack. If I've understood correctly, then, assuming a setup time of 10pm (BST), I'll need to :

Set time to Universal, which equates to GMT.

Set clock to 21:00 (as 10pm BST = 9pm GMT).

Select Daylight Savings.

Thanks again, one and all.

Boo

You don't set the clock as such more, like tell it what your local time is, so you enter 22.00 and the daylight saving takes care of it. If you actually enter UTC time (21:00) then don't select daylight saving.

As for finder scope alignment, for an object at infinity then the angle between the scope and the finder scope should be 0 degrees. Say the distance between the center of the scope and finder scope is about 100mm or 0.1 metres and the distance to the alignment object is 100m. Then the sine of the angle is 0.1/100 or 0.001 which gives an angle of 0.057 degrees which is an error of 3' 25 seconds. At 1km the angle is 0.0057 degrees or 20.5 seconds. For comparison the maximum angular diameter of Jupiter is 50 arc seconds.

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Hi, I'm new to astronomy

I had exactly the same problem with finder scope, I think mine is clamped with only one of the two screws, it's worked fine like that for 18 months. (It's only half on the clamping rail, finder is pulled very far back)

use daytime saving hours

most important thing I learnt was always finish your aligning moves with the same one the goto uses on the final approach to target, in my case to the right and down. It's almost central on target every time. It's very good.

once you get confident it's very quick and easy, I always use 2 star align, if looking for DSO's

Steve

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