Primary or Secondary???

[poider]

I assume this means my scope needs collimation?
https://flic.kr/p/LsG5dw
would it be the secondary or primary???

[poider]

I received no instructions on such and have viewed differing opinions on google???

[glend]

Yes it needs a collimation tweak. The circle should be even in thickness all around. Collimation has a few steps so i suggest you read Astrobaby's Collimation Guide as a start, you can download it and its free.

[poider]

Thank you glend I will have a look

[mental4astro]

Peter, if your scope is new, always take it as a given that its mirror alignment will need to be tweaked. These are held in place with components that are not held very tightly in place, so vibrations from moving the scope around will see the mirrors shift a little. Also, depending on the factory as to the care given to the scope's assembly as to how well put together it is and do how much of an adjustment needs to be done of the primary AND secondary.

I second Glen's suggestion of looking at Astro Baby's collimation guide. It is comprehensive without being complicated or too technical which makes it great for first time Newtonian users and is a great resource.

One note to keep in mind - being called "secondary" does not make this little mirror any less important than the "primary". In collimating your Newt, unless you have the secondary right from the beginning, it doesn't matter what you do with the primary, collimation will not be right. In aligning the optics, the secondary mirror is King.

With a Newt, you will find you'll need to tweak the collimation a little between sessions. Things will shift tiny amounts as you haul the scope about from use to stowing and out to use again. Collimation is not hard. Just a bit confusing to get your head around first time. Especially if you need to do big adjustments firsr time. But from then on, any tweaking is minimal and checking that everything is in good order becomes second nature as you realise that the two minutes it takes means that your scope will be purring at its very best.

Last thing, "laser" collimation tools won't deal with the correct positioning of the secondary mirror. You still need "old school " technology to get the secondary right, such as a Cheshire Eyepiece. You can then use a laser to help with the primary mirror. You can use a Cheshire Eyepiece collimate the whole scope, but a laser does make tweaking the primary easier with bigger tubes.

Alex.

[billdan]

I'm intrigued by what brand telescope it is, the scope has 3 spider vanes and what looks like a large secondary with a 40% obstruction.

If this is a RC then some special collimination tools are required.

Bill

EDIT: I didn't read the fine print, Starview EQ150 is a newt

[mental4astro]

This is a pic i found of the scope's front end :

204214

Modest scope and fine to start out with. From Peter's earlier posts, it's a National Geographic 150eq.

[poider]

I understand this is relatively inexpensive scope and know it will not be great for astophotograpy, but my wife bought it for me for Father's Day and I am determined to get the most out of it that I can

[poider]

Sorry mentalastro I wasn't in the least bit offended I will take all the help i can get, I was just letting everyone know that I wasn't expecting any miracles.
And that I was aware of the scopes limitations ( I think ) I would love to here aye in which I can improve my scope

[mental4astro]

Peter, my apology for misinterpreting your post.

You must have been overjoyed at the gift. You must have had scored some major brownie points to score this for Father's Day! :D

[poider]

It ws a sort of mutual purchase and as we do we blamed it on the next occasion to come and that was fathers day,i boked a cruise for 2018 and we blamed that on a mother's day gift.
So what does everyone suggest as improvements, I think I need to take some slop out of the focuser and barlow arrangement, and I am pretty sure I would benefit from a stronger mount, but of course that takes money so will have to wait, are there any improvements that are reasonably cheap, I am not a tech wizard or super handy man but I am capable of a few things tech and handyman wise??
Peter

[alocky]

Hi Peter,
For lunar, planetary and bright deep sky from a suburban backyard I would change very little with that scope. Your best investment will be taking the time to use it - such as getting some collimation tools and using them to adjust it. The next step might be to get some good eyepieces- as good as possible because they will stay with you no matter what telescope you have.
If you decide to get a huge telescope for dark skies, or get into astrophotography, keep this telescope as it is because it will always be perfect for a quick look at the moon or planets from home.
Cheers
Andrew.

[mental4astro]

Peter,

There's a few things you can/should check with your scope. While we take at good faith that the scopes we purchase are made as the Real McCoy, sadly there are many short cuts that are taken with the cheaper scopes. I've seen big brand scopes have unbelievable 'cheats' taken just to save a few cents, and leave these scope essentially crippled and requiring significant modifications to bring up to scratch.

Secondary Mirror
Check to see that the secondary mirror is firstly centred in the focuser. If you don't have a collimation tool, it is easy to make a DIY tool. The plug that fits into the focuser makes for a good makeshift collimation tool. Drill a little hole (approx 3mm diameter) dead centre. Insert the plug into the focuser and have a look through this new peep hole.

NOTE: Never collimate the scope with it pointing up! If for whatever reason something falls into the tube, if it isn't pointing up then it won't hit the primary mirror.

Look to see if the secondary mirror is roughly centred in the focuser drawtube. With the scope set horizontal and pointing to the left to give us here a reference tube orientation, if the secondary mirror is set too far to the left, you will need to shift the secondary mirror to the right, closer towards the primary mirror. I've seen one scope where the secondary mirror was not only too far to the left, but the centre bolt of the secondary holder and the collimation bolts wouldn't allow the secondary mirror to be shifted far enough to be centred!!! Such a situation requires the complete replacement of the centre bolt and the collimation screws.

If you should need to replace the bolts, of course replace thread for like thread or the bolts won't wind into place.

Primary Mirror
The cell of the primary mirror should have compression springs on the collimation bolts to facilitate the alignment of the primary mirror. First, check to see that there actually are compression springs here - I've seen rubber O-rings used in some scopes!!! These will NEVER allow the primary mirror to have sufficient movement for proper collimation. These O-rings will need to be replaced with compression springs.

If there are springs, all too often these springs are way too soft to work properly, and these should be replaced too. Springs to look for should be as close to the diameter of the collimation bolt as possible (these will have less of a tendency to buckle when loaded, and so throwing out the collimation and reducing the compressive loading of the springs. If the only suitable springs are too long, then just cut them!

How strong should the springs be? For a spring with a 6mm centre hole, and 15mm long, when pinched between your thumb and first finger you should struggle to completely close down the spring on itself. Better a little lighter than heavier here though.

Collimation
Here's a link to the Astrobaby collimation guide. You can use that modified focuser plug as your first collimation tool:

Astrobaby Collimation Guide (http://www.astro-baby.com/collimation/astro%20babys%20collimation%20guide .htm)

Take your time first off. Do this during the day the first time or two so that there is no 'star gazing' pressure on you.

Mount
Don't over tighten the clamp bolts.
Loosen the Dec clamp and have the scope and counterweights set 'horizontal'. Look to balance the scope in the Dec axis, moving the counterweights up and down the shaft until the system is balanced so when you release the Dec clamp the scope doesn't rise or fall. Next, with the scope still in this position, balance the scope in the RA axis, sliding the tube up and down its cradle until it is balanced, so when you release the RA axis the focuser end of the scope doesn't rise or fall. Balancing the scope in both axis will ensure the least amount of strain being experienced by the mount. If you load the focuser with a heavy eyepiece or particularly a camera, you may need to readjust the balance situation.

These are a few things you can look at to get the most out of your scope first off :)

Alex.

[poider]

Thank you Alex,I have began by removing the slack from the barlow / camera adapter. Then Have centered the secondary.
Tomorrow I will remove the primary and give it a clean (it looks like it has been sitting in a warehouse for years, then I will stick on a ring binder circle thingy and put it back in for alignment
Peter

[poider]

Done!!! Mirror removed cleaned and dried.
Ring sticker centered, mirror returned to rightful position.
Primary aligned with center of secondary, secondary aligned with Primary ........... I hope.....all looks good now these clouds can just go away and we should be able to test it properly
Peter

[poider]

So now i am thinking about upgrading the Focuser and have read here about an electric version, what does the upgrade include, do I just unscrew mine from my Australian geographic starview EQ150 newt and replace the whole thing and are the electric ones compatible with my scope?
Peter

[alocky]

Unless you're going to start imaging, and to be honest here I'd stand by my previous advice about keeping this as a nice visual instrument for bright objects in town, don't bother with a motorised focuser. A good 2" Crayford would be worthwhile though, JMI, moonlight, are reasonably cost effective options. There are plenty more!
It may require drilling new holes in the tube, and possibly enlarging the drawtube hole.
Cheers
Andrew.