New Joiner - SkyWatcher 130

[Littleguy80]

Thanks @kilix. There was a post that specifically recommended it for my scope so should fit. It's low down on the list right now but definitely something I think I'll be investing in at some point 

[Littleguy80]

Cheers Steve. I think that I'll only really need the UHC filter as I'm just going for visual. Not looking to do any serious astrophotography at this stage. There's quite a few different filters for DSO/Nebula and I'm only now starting to get to grips with what each of them does.

[happy-kat]

The red dot finder works well.

Go straight to top of list the book Turn Left at Orion. With that and the rdt you will find DSO.

[Littleguy80]

Thanks @happy-kat I've added it to my Amazon wishlist  I thought I'd have a go with the red dot finder and maybe think about upgrading that if/when I reach the point that I'm struggling to find stuff

[happy-kat]

The book covers how to star hop to find a DSO, you use the rdt to get you to the first star then you hop using the book to the one being looked at. All the other items on your list are a bit fruit cake unless you have actually located your DSO and the supplied 25mm will get you started. It is a good book and covers what expect to see.

[Alfian]

Regarding eyepieces I would be inclined to go for a decent 25mm rather than the 30mmm, but if you have good dark skies and you can get away with the larger exit pupil a 30mm might be OK. I used to have a Revelation 2.5x and it is a good barlow, some have claimed its more like a 2.25x but I never checked it out specifically.  Over the past few years I have tended to go for individual EPs rather than use a  barlow but I accept they are a useful accessory.  A reasonable quality 2x barlow of the type that has the screw off nose section that gives a 1.5x capability would be good. That would give you a 650mm,  975mm and 1300 mm focal lengths to play with. A 25mm and 9mm EP would give you 26x, 39x, 52x 72x, 108x & 144x. When I used a Celestron 650/130 I found about 185x was about the limit for me so another higher power EP might be needed, or jiggle around with something else barlowed. My favourite EP using the Celestron was the Vixen NPL 15mm which is a great little plossl EP.  Its worth looking through the for sale section here, there are often some good savings to be had. The Starguider/Explorer range are by reputation good ones to look out for.

[Littleguy80]

Thanks Alfian. That's a really good shout on the Barlow. Revelation do a 2x Barlow. I just checked and that can be used as a 1.5x as you suggested. I'm also glad you mentioned going for 25mm rather than 30mm. The BST Explorers and Celestron x-cels both stop at 25mm so I wasn't sure on whether to get 25mm in one of those or go for a 30mm in something else. I didn't realise there was a for sale section on here so will definitely check that out

[Alfian]

I have a 32mm Revelation plossl and it's a good EP but with an F5 scope it gives a 6.4mm exit pupil which is a bit much for me here, but as I say 25mm worked better. As well as the "for sale" section here, there is also astrobuysell which is a good source, usually, for 2nd hand gear. Also Astroboot is handy but be aware that since relocating their postage costs are more than they used to be.

[Alan64]

On 3/17/2017 at 19:09, Littleguy80 said:

Thanks again, Alan. There's so much choice when it comes to eyepieces, especially for planetary viewing. Whatever I get will be a significant improvement on what I have.

I've seen that you can get a motor for my mount. I can definitely see the benefits just from viewing Jupiter and seeing how quickly it moves at high magnifications. Definitely something I have on my list. I'll have to learn about polar alignment then

You're welcome Guy.

For visual use, an exact aiming at the north celestial pole(NCP) using the north star, Polaris, is not necessary, nor is it practical with an EQ-2 since the EQ-2 does not have provision for a polar-scope.  First, you would set the latitude-scale to your latitude, 52° N there in Norwich.  For example, my latitude is 34° N here in the States...

You only have to set that once, unless you were to relocate considerably northward or southward, like Newcastle(54°) or Brighton(50°).  

Once that's set, you then level and rotate the entire mount to where the RA-axis points to the NCP.  If Polaris is visible, then you can eyeball alongside the RA-axis and point it at the star...

In that your latitude is 52°, Polaris will appear 52° above the horizon.  Here's a photograph taken from the north door of my home, with Polaris 34° above the horizon, and with the light pollution of Memphis, Tennessee in the background, about 25 miles away to the north...

If the aiming at Polaris is not spot on, it will only amount to having to twist the slow-motion control of the declination-axis once in a while, and to keep the path on track.

If Polaris is not visible, you can use a compass.  Now, a compass points to magnetic north which differs slightly from true celestial north, but you can calculate the difference in degrees between magnetic north and true celestial north there in Norwich, and adjust the position accordingly.  You may want to go to that extra trouble in the event that you'd like to take some short photographic exposures with the kit.

[Littleguy80]

Thank you, @Alan64. Very useful info, as always  My collimation cap arrived today. It's cloudy here so I've spent the evening checking my setup. Collimation looks good... I think!

I've also set the RA axis to 52 degrees so hopefully I'm all set for some good viewing. 

I have a new eyepiece (8mm BST Explorer/Starguider) and a variable polariser. Will be looking for Polaris and Jupiter as soon as I have clear skies!

[Alan64]

There on the left of the mount, that's a nice extra feature, the bolt, in ensuring that the setting doesn't slip.  My EQ-2, which I had gotten back in the early '90s, only had the lock there on the side at right.  Had, I say, as I gave it to a relative many years ago.  I wish I had it back.  I'll be getting another in future, as it makes for a great grab-and-go equatorial, and as you will find.  Take good care of it, for you will return to it again and again, as quite a number of small telescopes can be mounted on it.

The collimation via the scene appears to be out a bit.  Here is the scene, brightened up a bit in order to illustrate the present issues and to offer solutions, so please bear with me...

Arrowed in green are the clips which hold the primary mirror within its cell.  Note that the one at the top is barely seen.  All three clips should be visible and evenly sized.

Arrowed in red is one of the four spider-vanes that's much longer than the other three.  Opposite of that one, arrowed in gold, is the vane which is shorter than all of the others.

You'll want all four spider-vanes more or less equal in length, and again, all three primary-mirrors clips to show evenly.

The underside of the collimation-cap is circled in red; and the pinhole through which you had snapped the shot of the scene, in blue.  Notice that there is one critical item missing within the red circle: the primary centre-spot, or "doughnut"...

Such helps to more accurately align the optical system.  A collimation-cap is useful in general for checking the collimation, but in order to utilise it to its full potential, and for collimating, then the primary mirror will require a centre-spot.  It's quite easy to do, and as detailed here...

https://www.cloudynights.com/topic/570729-uh-oh-how-can-i-tell-if-i-dented-or-fractured-my-telescope/?p=7775740

The OP within that thread has the same kit as yours, exactly.

First off, however, for now, I would only adjust the primary mirror to see if you might straighten that out a bit.  Don't adjust the secondary just yet, not until you're familiar as to its nature and mechanical complexity.  It may not even need to be adjusted.  It may be that only the primary mirror is out of adjustment, and that's the easiest assembly to adjust, there at the rear of the optical-tube...

You may find that the only issue is that the primary centre-spot, if it were present, simply requires moving and centring it over the pinhole of the cap...

...and adjusting the primary mirror will take care of that misalignment.  But since the primary is not centre-spotted, you will not see it in action as you adjust the screws.  Therefore, simply make small adjustments there at the primary-cell until you see that the spider-vanes are equal in length and that all three primary-mirror clips are showing evenly.  Again, don't adjust the secondary mirror until you research its many facets, as it's the most complex assembly within a Newtonian...

Collimation instructions... http://www.forumskylive.it/Public/data/serastrof/201281510358_Astro Babys Guide to Collimation.pdf

There is another way to collimate, but others still prefer the tool-method...

http://garyseronik.com/no-tools-telescope-collimation/

It's all up to you, in so far as how far you wish to obsess over the getting the collimation spot on, and for the sharpest images at the higher and highest powers.  At the low-to-moderate powers, the alignment need not be as critical for pleasing views, but in that a telescope is for observing faraway objects up close, in the first place, then it pays to learn, and master, the art of collimating a Newtonian.