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Skywatcher 150PL EQ3-2 need some advise.


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Hello everybody :)

Recently I bought myself a telescope , I am a beginner in this field but I would like to use it for both DSO and Planetary if it's possible. If someone could answer my few questions it would make things more easy for me.

Lets start, my first one is can I set it up in my lounge instead of the garden ( still too cold for me outside ). I know I limit my view but the question is about mirror temperature, is it better to be outside or it doesn't matter.

I treated myself for start to a Antares Collimator, Polarscope, 7.5mm Skywatcher SP Plossl, 20mm Vixen NPL, 15mm William Optics Swan(backorder 2 weeks). Could you tell me if its a good buy or I am missing something.

My mount is not to stable as the 150PL is long but the biggest movement is where Dec. Lock Knob, is there a way to make it better.

I had a look few nights ago and the image was not to good with the standard 10mm and 25mm that came with the telescope but when insert the collimator I could see it wasn't right on the primary or secondary, couldn't adjust it because didn't have the key for secondary(is it little hexagon or what).

Really looking forward to some good weather and views after proper collimation.

Thanks

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You don't really need a collimating tool for an f/8 scope (in fact IMHO you're better off without one), a simple peep sight made by drilling a 3mm hole in the middle of the bottom of an old 35mm film can will do.

can I set it up in my lounge instead of the garden ( still too cold for me outside ). I know I limit my view but the question is about mirror temperature, is it better to be outside or it doesn't matter.

It matters a lot, unless the glass in your windows is optical quality (1/4 wave or better) in which case it will cost about £1000 per square foot. Treat yourself to some decent cold weather clothing: for astronomy, where you're not moving around much, you need to dress the way a mountaineer would for temps 20C lower.

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You don't really need a collimating tool for an f/8 scope (in fact IMHO you're better off without one), a simple peep sight made by drilling a 3mm hole in the middle of the bottom of an old 35mm film can will do..

Would the same method work for an f/5 scope?

Sorry to hijacking the thread!

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To fix the Dec wobble you need to remove the worm gear using the four allen screws around where the slow motion control attaches below the saddle. Remove it, if you have grease clean it and clean the whole sprockety thing by tuning the dec around and wiping it and then regrease. Not entirely needed but if you can then do it.

The other thing to fo is take out the cap for the polar scope end and look in the hole and you'll see the nut that holds the Dec on. Get a spanner on it and turn the dec to tighten it a smidge. Put the whole thing together again and you'll find the slop's a lot, lot less.

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I would sugest taking your scope to a local astronomy club in London. I went to one last night for the first time and i can honestly say they were a great bunch of guys, very helpful and will help you set up your scope.

Just google astronomy clubs for the London area.

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You don't really need a collimating tool for an f/8 scope (in fact IMHO you're better off without one), a simple peep sight made by drilling a 3mm hole in the middle of the bottom of an old 35mm film can will do.

If I have one is it better to use it or not? It wasn't to bad it was just touching outside of the circle on the primary mirror and the one on the collimator was little bit off as well (not much).

Regarding the set up I don't look through a window I open the doors to the garden.

Edited by IScreamMan
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To fix the Dec wobble you need to remove the worm gear using the four allen screws around where the slow motion control attaches below the saddle. Remove it, if you have grease clean it and clean the whole sprockety thing by tuning the dec around and wiping it and then regrease. Not entirely needed but if you can then do it.

The other thing to fo is take out the cap for the polar scope end and look in the hole and you'll see the nut that holds the Dec on. Get a spanner on it and turn the dec to tighten it a smidge. Put the whole thing together again and you'll find the slop's a lot, lot less.

Thanks for that I will look at it. Do you use a collimator or not. Any tips from a owner of 150PL.

Edited by IScreamMan
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Hi IScreamMan

quote" Regarding the set up I don't look through a window I open the doors to the garden. unquote"

This will be a little better but you will still be having problems with heat escaping from your nice warm room through the window. This will give lots of atmosheric disturbance as the heat escapes through the window making a mess of any objects you are trying to look at.

The best way to view is to put the scope in the garden for an hour ish to cool properly before you want to observe, then wrap yourself up as warm as you can and then join the scope. You will be amazed at the difference to the views. This will give more stable images and you will get far superior views than looking through a window, closed or open.

When you start to feel the cold just pop back indoors and get warm for a few minutes. Then when youve warmed up go out and rejoin the scope for another session.

Oh and Ive had 2 EQ3 mounts and the dec backlash has been the same in each, try adjusting the backlash as others have suggested, it works quite well.

Phil

Edited by philj
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Hi yes its a hex or "allen" bolt and I believe its 2mm, am not at home so cannot check (bike shop or B&Q). My scope needs about 30 mins to cool in garden and holds collimation very well, without cooling tube currents will destroy view. Check out Astro babies guide its very easy to follow and very good. As a 150PL user I would strongly recommend you get the motors to fit the EQ3-2 as this removes almost all wobble and is able to keep your target centered in view for a long time with even basic polar alignment. I found the free EP's better than most people think, but have moved to TV Plossls and am loving them.

Hope this helps.

David

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If I have one is it better to use it or not?

The issue with collimating tools is that they have to be very accurately constructed and mounted absolutely square in the drawtube if they're going to work properly. The colli cap is much less sensitive to this effect, but also less sensitive to accurate collimation - which is why it works fine with f/8 scopes, or f/6 at a pinch, but is really not good enough at f/5.

But worrying about collimation is a complete & total waste of time if you're going to observe through window glass, or without giving your scope time to cool to ambient temperature.

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Thanks for that I will look at it. Do you use a collimator or not. Any tips from a owner of 150PL.

Personally, I use a collimator but you can get by with a colli cap of some sort like a film can. A cheshire is just a similar thing but a lot longer with a crosshair at one end.

When I collimate it's a quick look down the collimator and line up which is very, very nearly perfect. Doing the same with the collicap I made checks out as being about the same with the cheshire.

I think going down the film can route is good for the scope but you might feel you want a proper collimator just because you want one but not on the account of collimation issues.

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As you have the collimator you may as well use it.

If not now then if you get a large scope and if it is a newtonian you will have to use one so get the idea of one now when the scope is forgiving of learning errors.

Also 35mm film tubs are collectors items now.

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