First scope advise please.

[NIGHTBOY]

I posted another thread on this in the wrong section so please excuse...

I've been looking at the Skywatcher 130p and read nothing but great reviews. As a total noob I will be starting off with the moon then moving onto planets etc, the usual scenario!! Out the back of my house is real dark so it will be a good place to begin, I feel the need for a tripod is a must due to fences etc. I work on a farm in the middle of nowhere and it's also on top of a big hill so that should be a great place also (although the wind might be my worst enemy).

Now back to the scope. I really don't want to jump in  both feet first and spend 100's so I rather start off with a reasonable scope and spend the extra on good eye pieces, as I use to hunt/shoot at night under a lamp I realise the difference good glass can make.

If anyone's got any advise on a good set up in the £200/250 margins I'm all ears. I'm in no rush to buy as I'd like to gather all the info I can first.

I'm in your hands!!

Many thanks, Steve.

[Schorhr]

Hello Steve,

a stable table or box and the heritage 130p will be more rigid then the 130/650 on the budget mounts/tripod.

If you can stretch your budget to 270-280£ / 330€ you'd be able to buy a 8" dobsonian that will show you much more then a 5" telescope.

http://clarkvision.com/visastro/m51-apert/

http://translate.googleusercontent.com/translate_c?depth=1&nv=1&rurl=translate.google.com&sl=de&tl=en&u=http://www.binoviewer.at/beobachtungspraxis/teleskopvergleich_deepsky.htm&usg=ALkJrhidF6g0miZxrqxLgQvo-oxZsVXRzA

But most of the time you'll discover how anoying neighbor's lights street lights and so on really are, and a 5" is much more portable...

I myself use the smaller telescope the most, due to the ease of setup and portability.

A tripod usualy is more bulky, and the sets usualy contain a mount that's a tad to weak to carry the telescope, especially for high magnifications.

[Zuben Elgenubi]

Dobsonian telescopes are commonly recommended as they are simple to set up and use, and they offer the maximum aperture for your money. Most are manually operated which means that you will need to learn how to locate things in the sky - this may or may not be a good thing depending on your point of view!

If the idea of this type of telescope appeals then the Skyliner 150P sits at the lower end of your budget, while if you were able to push the upper limit by £30 or so then the 200P becomes available. They both come highly recommended.

http://www.firstlightoptics.com/dobsonians.html

Of course there are other types of scope available so take your time and read as much as you need to make the right decision. It took me a few months to finally make up my mind about which scope to buy. I got a 200P and have not regretted my choice!

Gareth

[NIGHTBOY]

Thanks all. I must say I do like the look of the Dobsonian scopes and another winning point for me would be easy storage. The only down side is I would need to use a table etc to get a good view of the moon as our garden isn't very big and because of fences etc I don't think it would be in view from off of the floor (will post a pic later) . I'm all for spending the extra on the scope itself rather than what it's sitting on tho. Is there any different eye pieces you'd recommend getting if I went for the 8'' Dobsonian or would it be a good 'all in one' package??

Steve

[NIGHTBOY]

Also, has the flextube version got any advantages over the solid one??

[rowan46]

The 8" dob is about as good as it gets unless you want to spend mega money. In fact it is better on many things than some scopes 2 or 3 times the price. One word of warning on dobs though is if you want to photograph anything through the scope a dob is not a very good scope to use. It can't be used for any object that requires a long exposure.

[Schorhr]

Hello,

the 5" Flextube is more portable and just fits into a larger backpack, it's light weight, but of course it has some downsides.

The open truss will make it vulnerable to stray light, but a sheet of cardboard makes a simple light shroud that will slide into the tube for storage.

The aperture ratio of a telescope is importaint too; At f/5 (=focal length devided by aperture, all in millimeters) the outer field on cheap eyepieces won't be completely sharp and in general coma will be visible (elongated stars), but IMHO that's not that critical as beginner, and bothers some more, some less...

Plössl, Erfle and such will have problems around/under f/5, at f/4 most will consider a coma corrector as neccesary. The HR/TMB planetary eyepieces still perform fairly well at f/5.

F/6 is much more forgiving on most eyepiece designs, so this and the higher build are a plus of the lrarger dobsonian.

Also collimation/adjusting the primary mirror is less often neccesary on a full tube, though I find my h130p keeps colimation quite well for all the bumping around in my backpack ;-)

You can use a sturdy wooden box as storage and table of the heritage 130p, and as objects just over the horizon suffer from seeing/athmospheric turbulances and heat turbulances (warm road, cooler air), you will be observing higher up most of the time anyway.

The 8" could be placed on something as well, and if it's just a bunch of boards slapped together, but there are many solutions possible of course.

A tripod will be up higher, but if there is a lot in the way it will most likely cause problems, too. Also leep in mind if you do decide on a equatorial mount the eyepiece/focuser of a newtonian will rotate all over the place, and will either make viewing a bit difficult or require you to turn the tube again multiple times.

[NIGHTBOY]

Well I'm about to take the plunge on this beauty..

http://www.ebay.co.uk/itm/SKY-WATCHER-SKYLINER-200P-203MM-8-F-1200-PARABOLIC-DOBSONIAN-TELESCOPE-/281167774096?pt=UK_Photography_Telescopes&hash=item4176e7c190

 most my viewing will be done from my house so transport isn't an issue....

[Zuben Elgenubi]

Wow, that was quick 

You will need a collimation tool to keep the mirrors correctly aligned:

http://www.firstlightoptics.com/collimation/cheshire-collimating-eyepiece.html

Astro Baby has a good guide to the collimation process:

http://www.astro-baby.com/collimation/astro%20babys%20collimation%20guide.htm

[Schorhr]

Yep, that's the one, also check out other vendors though.

Find a vendor that will replace the optical finder and the cheap 25 and 10mm eyepieces. Some offer to make a good deal on a set.

IMHO a better finder is a telrad or Rigel quick finder, or a combination of both.

Instead of the eyepieces a budget solution could be uwa 30€ or better 45€ hr/tmb...

About the size,

http://translate.googleusercontent.com/translate_c?depth=1&nv=1&rurl=translate.google.com&sl=de&tl=en&u=http://taunus-astronomie.blogspot.de/2007/03/teleskope-im-groenvergleich.html%3Fm%3D1&usg=ALkJrhg_dz4uFwVftSyzOgb6SE-Hq8eHeg

(translated)

;-)

[Schorhr]

+1 for the Cheshire sight tube!

And a red light, warm clothing...

[NIGHTBOY]

Do First Light Optics offer such a deal???

[NIGHTBOY]

I must say after reading that I'm not looking forward to the collimation set up :/

[Prador]

You have picked a cracking first scope there!

This is my own personal opinion but I would pay the extra tenner to get the scope from a non ebay source and have top notch customer service/aftersales.

Collimation is just one of those things that seems daunting until you do it a couple of times. Then it is easy and accomplished is a few minutes, if that.

Dave

[NIGHTBOY]

You have picked a cracking first scope there!

This is my own personal opinion but I would pay the extra tenner to get the scope from a non ebay source and have top notch customer service/aftersales.

Collimation is just one of those things that seems daunting until you do it a couple of times. Then it is easy and accomplished is a few minutes, if that.

Dave

Thanks Dave and yes you're right, I will be buying from First Optics

[Schorhr]

Just ask for alternative offers, but actually you won't be dissapointed even with the stock eyepieces and finder.

It's just a method to save a few bucks if you contact the dealer and might be able to get a better bundle right away.

But as they can only sell the included optics themselves the savings are of course limited.

Collimation was confusing at first and perhaps even a bit scarry, but it's very easy once you followed one of the great online guides.

The difficulty is overrated.

Doing it with the tools actually infront of you, it's not hard. And after practice you will be able to check collimation within two minutes ;-)

[NIGHTBOY]

Just ask for alternative offers, but actually you won't be dissapointed even with the stock eyepieces and finder.

It's just a method to save a few bucks if you contact the dealer and might be able to get a better bundle right away.

But as they can only sell the included optics themselves the savings are of course limited.

Collimation was confusing at first and perhaps even a bit scarry, but it's very easy once you followed one of the great online guides.

The difficulty is overrated.

Doing it with the tools actually infront of you, it's not hard. And after practice you will be able to check collimation within two minutes ;-)

Ok well I'll take your word for it!

So! It's been ordered!!! The skyliner and collimation tool should be with me this week, £317 in total which was a little over budget but I feel if I'd of gone for the 130p I'd always be wanting bigger...

I'm hoping a member on here can assist me with the collimation as I'd much prefer to see it being done 1st hand rather than going in blind and reading from instructions tho I'm sure I'll get there. Looking forward to its arrival

[Schorhr]

Congratulations!

Actually, I bought the h130p after owning my larger telescope to have something portable. No matter how much reading you do, even if you visit observatories or star gazer parties, you'll eventually find out after a while you want to observe different things. Many want to look at the moon and planets, but end up getting fascinated by deep sky objects as well ;-)

Anyway, even a not well collimated telescope will show a lot. Don't worry too much and do it step by step.

If you can find some fellow star gazers locally even better.

If the telescope includes 10 and 25mm eyepieces, you will have 120 and 48x magnification.

You may want to get

http://m.ebay.co.uk/itm/200607942106?nav=SEARCH&sbk=1

decent, great for the price, and will provide you with higher magnifications on moon and planets.

Also

http://m.ebay.de/itm/360459084615?nav=SEARCH&sbk=1

It has no eyecup (pipe isolation can be used for example) but it's a cheap, decent overview eyepiece until you gather enough money for a 2" with 30 or 35mm that will have a larger aparent field of view, such as

http://m.ebay.co.uk/itm/390605234485

And HR/TMB, UWA eyepieces... Soon you will discover you can spend much more on eyepieces then on the telescope itself! ;-)

But really, Plössl are great to start with as they cost only a fragment.

Just on wide angle 2" eyepieces there are little to no alternatives, unless you order some diy kits at surplus shed, USA. (about 26 EUR shipped for a 2" erfle lens kit)

[NIGHTBOY]

So using the barlow lense, do you put that in then the eye pieces go on top of that??

[Schorhr]

Yes, you put the barlow into the telescope focuser, then the eyepiece into the barlow.

The barlow contains a set of lenses to increase the focal length, and thus increasing the magnification. The lens will introduce color fringe, if you view planets or the moon you will notice a blue seam on one, a yellow one on the other side on bright objects. This (and the aditional glass) will reduce contrast a bit.

Achromatic barlows, even the 16-17€ one, are better then those cheap 8-15€ plastic ones, but not as good as ED barlows that have little fringe.

But those are more suited for photography or high end eyepieces, as at the beginning it's better to get one or two decent eyepieces and just use a cheap achromatic barlow "to fill the gaps" in your magnification palette ;-)

But everyone has their own oppinion on barlows. A Plössl instead of a barlow can also be a good solution, though under 10mm the eye relief of Plössl get's rather bad, at 4-6mm they are difficult to view through!

[NIGHTBOY]

Yes I follow. There is one on ebay ending shortly, it's the metal type but is 3x, would it being 3x cause any problems??

[Schorhr]

I have both a 2x achromatic seben/orbinar barlow (16,49€ shipped) and a 3x achromatic Meade (19€ shipped). The 3x I received has a worse black coating and the fringe is worse, but other barlows may be diferent.

Most of them are from the same factory, so if they look similar, they probably are at least comparable in performance.

3x also might a bit much depending on your eyepieces.

On the heritage 130p a 20mm and 3x and 2x can theoretically cover all useful magnifications, but the same magnification with a 3mm eyepiece results in a better image and it's less of a hassle getting into focus.

Also you will see every dust particle on the glass when using a barlow.

On a larger telescope with 1200mm focal length a 10mm eyepiece and 3x barlow will be magnifying too high, at least on common seeing/sky conditions, even though a 8" could provide 400x.

[NIGHTBOY]

I have both a 2x achromatic seben/orbinar barlow (16,49€ shipped) and a 3x achromatic Meade (19€ shipped). The 3x I received has a worse black coating and the fringe is worse, but other barlows may be diferent.

Most of them are from the same factory, so if they look similar, they probably are at least comparable in performance.

3x also might a bit much depending on your eyepieces.

On the heritage 130p a 20mm and 3x and 2x can theoretically cover all useful magnifications, but the same magnification with a 3mm eyepiece results in a better image and it's less of a hassle getting into focus.

Also you will see every dust particle on the glass when using a barlow.

On a larger telescope with 1200mm focal length a 10mm eyepiece and 3x barlow will be magnifying too high, at least on common seeing/sky conditions, even though a 8" could provide 400x.

I see so probably best to stick to a 2x for now then, I'll get one ordered

How do you go about cleaning the dust off before use?? (sorry for all the questions haha)

[Schorhr]

Regarding optics, as little cleaning as possible is usual better ;-)

Finger prints can damage optical coatings though, so those should be cleaned. You will find different aproaches if you search the forum, most important is to prevent water from getting into the eyepiece, but never dry clean as micro fibre clothes and such can rub dust and other particles over the surface causing tiny scratches.

destilled water, isopropyle alcohol and such are usualy recommended.

If it's only dust, get one of those camera dust blowers.

avoid other cheap dust blowers that can cointain powder or oil residue. Same compressed air cans.

Regarding eyepieces and magnifications, there is a bit of technical background that explains what to choose.

Eyepiece-focal length devided by telescope-aperture ratio will give you the "exit pupil", the diameter of light exiting the eyepiece.

Your iris will open about 7mm in complete darkness and depending on your eye, age and so on.

Under "urban skies" 5-6mm is more realistic. If an eyepiece has an exit pupil of 8mm, the light is 'wasted', meaning you will see less details then possible.

Under a exit pupil of 1mm many have issues with floaters, residue in your eye fluid. Also under 1mm exit pupil you won't see much more details, even though the image gets larger.

Under 0.5-0.6mm the image gets dark and lacks of contrast, 0.5mm is usually only suitable for double stars and very bright objects such as moon and planets, under dark skies for bright deep sky objects perhaps.

Ideal for deep sky observation is a 2-4mm exit pupil, but it really depends on the object. Some smaller ones may require high magnification, but if the exit pupil is too small, the image will be dim and details too faint to see.

The other rule of thumb is that the aperture diameter in millimeters times two is your maximum magnification, and usual that's what shops and manufactors state as maximum magnification in their product description.

On a 8" - 200mm telescope this would be 400x, but in reality, for these large apertures, 200 to 250x is the limit on good conditions. So don't buy an eyepiece to get 400x, for those rare clear nights a barlow will do.

As overview you want to go as low as possible to get a good overview, it will make it easier to locate objects. And this is where it gets a bit difficult, as the 1.25" eyepiece tubes / focusers limit the diameter / amount of light.

So that's what 2" eyepieces are for, but larger lenses mean higher cost ;-)

A 30-32mm Plössl with 50-52 degree of aparent field of view is about the maximum on 1.25", a 40mm Plössl seems like a good idea but it only has a 40 degree afov, so it shows the same real field, just with a narrow field of view - and a larger exit pupil!

A 35mm erfle or something like that should be one of your next purchases, keep your eyes peeled for some used offers ;-)