I have finally ordered a skywatcher 150p tabletop scope.... collimator questions

[Alex_o0]

Hi friends,

I have finally ordered the skywatcher 150p tabletop dobsonian telescope with 2x Barlow (My first scope) And super excited to start when it arrives.

Do these scopes come collimated ?  
Also I have read how easy it is to use a laser collimator, they range in prices and have read that some are actually no accurate, if I headed down this path what would be a good laser collimator ?

Any other tips are welcome too please

 

Thank you 

Alex 

[Les Ewan]

I've had Newtonians for over 40 years ranging from f4.8 to f 8 and managed perfectly well without a laser collimator in fact amateurs have managed for decades without them. Up to last year all I used was a simpe collimator eyepiece cap,I now have a non laser Cheshire collimator which in my opinion is all that is needed especially for short instruments.

The telescope should be pretty much collimated when it arrives unless it was severely bumped in transit but it will need attended to eventually.You may be lucky I used a Helios reflector for many years and it never needed collimated.

Collimation is nothing to be afraid of the biggest headache is if you unscrew a primary adjuster too far and it comes out, no damage is done but they can be a devil to get back in. What I usually do is screw them in as far as the will go then a back them off a turn or two and adjust from there using tiny increments. I know it sounds daunting but after doing it a few times you get the feel of it.

[Jiggy 67]

Many cheaper laser collimators require collimating themselves which can be more of a pain than collimating the actual scope! I have the HoTech laser collimator which is expensive but an outstanding collimator. It does not require collimating and uses a compression ring to centre itself in the focuser, unlike many cheaper versions which rely on the focuser screws which squew the collimator off centre. The HoTech makes the process very easy and is very accurate. It also uses a “star” like laser point rather than a dot which assists with the finer adjustments

[johninderby]

+1 for the Hotech. Not cheap but as they say you get what you oay for and the crosshair it projects makes it easier to use. Many cheap lasers just project a blob as well as needing collimating. 

Wish FLO would start stocking the Concentre colimation aid. I now consider it an essential in getting the secondary perfectly adjusted in particular.

https://www.teleskop-express.de/shop/product_info.php/info/p5507_TS-Optics-Concenter-1-25--Collimation-Eyepiece-for-Newtonian-Telescopes.html

[Jiggy 67]

8 minutes ago, johninderby said:

Wish FLO would start stocking the Concentre colimation aid. I now consider it an essential in getting the secondary perfectly adjusted in particular.

I got one of these a few weeks ago but I just can’t seem to get the circles focused properly in the focuser 😢 if you know what I mean, they are blurrd

Edited September 8, 2020 by Jiggy 67

[Chris]

I regularly use the Heritage 150p and don't use any type of collimator. It comes with a collimations cap to check the secondary which only really needs doing once unless you knock it, and to check the primary you just point the scope at Polaris (because it doesn't move) with a high polar eyepiece, place it in the centre of the eyepiece and defocus the star a little until you get a doughnut shape with concentric rings. If the rings are pinched on one side then the collimation needs adjusting. If it's all symmetrical then it doesn't  

[happy-kat]

Unless it is really out its not like you can't still observe. I too just have a cap to use with the smaller heritage 130p. If you were imaging then collimation is key.

Enjoy your telescope.

[johninderby]

Small newts / dobs are more likely to arrive still collimated and stay in coimation and should just need a minor adjustment..

Edited September 8, 2020 by johninderby

[Alan64]

Hi Alex,

Ah, you got the "Heritage" collapsible; very nice...

https://skywatcheraustralia.com.au/product/6-tabletop-dobsonian/

I have an Orion(of California) 150mm f/5 tabletop, a solid-tube...

Both the Orion and Sky-Watcher are produced by the same manufacturer, Synta.  My own arrived well-collimated, but that's because they had tightened, torqued, the secondary-hub's screws down at the factory, and for the trip overseas.  Else, it would not have held its factory-collimation.

I'm afraid it's as roulette in that; luck of the draw, a kiss and a promise, et al. 

Laser-collimators are for much larger and longer Newtonians.  Ours are short enough whereby we may look into the focusser and reach back and twiddle the primary adjustment-screws, simultaneously.  In addition, cheap laser-collimators require checking upon arrival, and are usually out of collimation themselves.  They must be checked and collimated once they arrive, and before using it to collimate a telescope.  The finest laser unit, perhaps arguably, is a Howie Glatter.  They reputedly arrive collimated 99.999% of the time, but for a price.

Rather, I use both a Cheshire and collimation-cap, with one being the fail-safe for the other.  As a result, I get rivetingly-sharp views, and at the higher powers even.  A Saxon Cheshire, for example...

https://www.opticscentral.com.au/saxon-1-25-cheshire-collimator-eyepiece.html#.X1chhyhKiUk

A Sky-Watcher Cheshire...  https://www.ozscopes.com.au/skywatcher-newtonian-collimation-eyepiece.html

If you'd like to include a Cheshire with the collimation-cap when collimating,  go with the Sky-Watcher, but not because you have a Sky-Watcher telescope.  I don't know who makes the Saxon; perhaps Synta, who makes the Sky-Watcher.  

Collimation instructions; these are specific to the smaller collapsibles... https://garyseronik.com/a-beginners-guide-to-collimation/#more-169

There are many other instructions and tutorials online on how to collimate a Newtonian, and if you get stuck we're here to help.

If I'm not mistaken, Jupiter, Saturn and Mars transit high enough in the sky there in Australia.  If you'd like to see more detail, you may need to dim them down a bit, and with a variable-polariser; for example...

https://www.bintel.com.au/product/orion-variable-polarising-filter-1-25-inch/?v=322b26af01d5

Simply screw it onto the bottom of an eyepiece, then twist to adjust, and usually in allowing from 1% to 40% of the light to pass through...

Jupiter...

Mars, if excessively bright...

When using the filter for Venus, you will be able to detect the planet's Moon-like phases more clearly.  Venus is the brightest of the three planets, by far.

A variable-polariser is only useful for dimming the brighter and brightest objects in the sky; the Moon included, particularly when near full-phase.  Only you can decide if it's worth purchasing.

Plossls are the minimum in performance eyepieces, and represent a great value.  You may also need a 2x and even a 3x barlow for reaching the higher powers, and where "Wow!" and "Look at that!" are heard.

Edited September 8, 2020 by Alan64

[Alex_o0]

Thank you @Alan64 for such a detailed answer and with Australian links  

You are correct Jupiter, Saturn and Mars transit high enough in the sky here in Australia.

Great info around the variable-polariser didn't know they existed until now, sounds like something I must add it my list. The one you mentioned is out of stock is the below a good substitute ?

https://www.ebay.com.au/itm/SVBONY-1-25inch-Variable-Polarizing-Filters-For-Astronomic-Telescope-Eyepieces-/174413078735?_trksid=p2385738.m4383.l4275.c10

 

I have already purchased the following 2x barlow  

http://www.astroanarchy.com.au/Accessories/Saxon_Barlow2xT2.html

 

Edited September 8, 2020 by Alex_o0

[Alan64]

1 hour ago, Alex_o0 said:

Thank you @Alan64 for such a detailed answer and with Australian links  

You are correct Jupiter, Saturn and Mars transit high enough in the sky here in Australia.

Great info around the variable-polariser didn't know they existed until now, sounds like something I must add it my list. The one you mentioned is out of stock is the below a good substitute ?

https://www.ebay.com.au/itm/SVBONY-1-25inch-Variable-Polarizing-Filters-For-Astronomic-Telescope-Eyepieces-/174413078735?_trksid=p2385738.m4383.l4275.c10

 

I have already purchased the following 2x barlow  

http://www.astroanarchy.com.au/Accessories/Saxon_Barlow2xT2.html

 

Anything extra added to the optical path can only degrade an image, or not adversely affect it at all.  Many use barlows, diagonals, and filters with their telescopes, but you want those additions to be as invisible as possible to the telescope's optics.  Now, that doesn't mean that you have to sink a lot of money into those items, but you do want a happy medium, a balance.  Concrete-cement between two bricks is better than cake-frosting, but a solid piece of stone is better than both; albeit for the lack of a better analogy.

The barlow you've chosen is from a reputable brand, and consistent in quality for the most part. 

SVBONY has been around for a while.  I don't have any of their products myself, but I've not read of any outstanding complaints.  In the end, I cannot tell you either yea or nay.    

[jetstream]

Buy one of these or similar, we have a Celestron version and use the saved cash for some nice high power eyepieces IMHO.

https://www.firstlightoptics.com/other-collimation-tools/astro-essentials-cheshire-collimating-eyepiece.html