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Hello everyone.

I'm now starting this hobby, and I'm thinking to buy a telescope.

I have a small budget, so I've narrowed my choices to this two:

celestron astromaster 130 eq

skywatcher explorer - 130/900 eq2

which one should i choose?

Thanks for the attention.

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As nightfisher has said, A dobsonian is a good choice. for a fair bit less you can get this

http://www.firstlightoptics.com/dobsonians/skywatcher-heritage-130p-flextube.html.

It has the same aperture as the one you have listed with a much sturdier mount,

alternatively for a bit more you could go for this:-

http://www.firstlightoptics.com/dobsonians/skywatcher-skyliner-150p-dobsonian.html

Good luck with your search

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About the mounted skywatcher heritage dobsonian, what is the maintenance that I have to do with it?

PS: what is the difference between a spherical mirror and a parabolic mirror?

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...

PS: what is the difference between a spherical mirror and a parabolic mirror?

It affects how well the light is focused to a small point - and thus how stars appear in your eyepiece. A parabolic mirror brings all the light to the same point, a spherical mirror tends to 'smear' the light into a blob so sharp focus cannot be attained without some sort of corrector. In fact some of the small scopes with spherical mirrors ARE fitted with such a corrector lens so performance is not as poor as you might expect. Parabolic mirrors are more difficult to make than spherical ones - hence they are more expensive to produce (and the cheapest scopes use the cheapest option).

ChrisH

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I think the Celestron astromaster 130 eq is a parabolic mirror whereas the Skywatcher explorer - 130/900 eq2 is a spherical mirror.

On that basis i suggest the Celestron.

I agree with ronin - avoid the Skywatcher explorer - 130/900 eq2 like the plague. It does have a spherical mirror and thereby has a "corrector" lens at the bottom of the draw tube. If you do go for the Skywatcher try the Explorer - 130P with a focal length of 650 is a better bet.

how about a skywatcher dobsonian, a good way to learn the night sky

As Nightfisher says what about a Dob. better bang for your buck.

Ian

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After all of your advises, I've decided to go for the dobsonian that auspom recommended. I've read more reviews about it, and, besides some manufacturer damages that some people complained about, it seems like an awesome scope to start with

Thank you all for the quickness of your answers, and when the telescope arrives I will tell you more about it.

Thank you very much once again:  alvster

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A Dob is a great way to start and more bang for your buck
I was tempted to go for a big Dob but as I'm more into Astro Photography I went down the EQ mount road
though I'd love to get a 12" Dob just for observing DSO's, while the 200 images others ;)

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I think the Celestron astromaster 130 eq is a parabolic mirror whereas the Skywatcher explorer - 130/900 eq2 is a spherical mirror.

On that basis i suggest the Celestron.

I agree with ronin - avoid the Skywatcher explorer - 130/900 eq2 like the plague. It does have a spherical mirror and thereby has a "corrector" lens at the bottom of the draw tube. If you do go for the Skywatcher try the Explorer - 130P with a focal length of 650 is a better bet.

These telescopes often cause confusion.

The short-tube Celestron 130EQ is fitted with a spherical mirror so works well at low-medium magnifications but struggles at high magnification. 

The f7 Skywatcher 130 (900mm focal length) also has a spherical mirror but at f7 a spherical mirror is perfectly adequate. 

Some believe the Skywatcher 130p's more complex parabolic mirror is made to a higher standard but that isn’t true. Where a telescope’s tube length is long enough to permit a spherical mirror there is little, if any, benefit to having a parabolic mirror. The 130p with it's short tube 'needs' a parabolic mirror (see ChrisLX200's earlier post) but the longer tube 130 doesn't. 

The Skyhawk 114 is the one to avoid (sorry Skywatcher) because it combines a short tube (for convenience) with a spherical mirror and uses a non-removable barlowing element in the focuser drawtube to achieve a focal length equivalent to f10. We don't stock the Skyhawk 114. 

For more on these telescopes please see this discussion

HTH, 

Steve :smiley:

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I can vouch for  dobsonians as they are easy to use and ,with a little maintenance, can see lots of detail for a relatively cheap price. I can also tell you that Sky-Watchers in particular are very good quality (though I haven't used any other brands to compare... :icon_confused:). I find the collimation of my dob no problem at all now that I'm used to it so it's nothing to be worried about. Enjoy your scope! :) 

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Regarding the Skywatcher Heritage 130p, does half open tube effect it's performance in any way? Also, how are users happy with it's eye piece holder since - it looks like a hassle to use.

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It's focuser is a bit sloppy but works (some use ptfe tape, I find it okey as it is).

The tube can be covered by a cardboard tube to block stray light, the tube then slides into the tube of the heritage so it does not influence the mechanism but greatly improves contrast under light polluted skies.

It is a very nice telescope for the low price, for planets a 4" or 5" Mak is a better choice (or a 6" dob even), but regarding deepsky and a good allrounder entry level scope the h130p is tough to beat :-)

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just checking in.

I still haven't bought the telescope, but i will have to buy it from amazon, because, unfortunately,  FLO doesn't ship items to Portugal.

I will probably buy it this weekend, so it will get here next week!

can't wait to try it.

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Don't buy the overpriced sets ;-)

Most sets contain stuff you will rarely use, or low qualiy accessories, or eyepieces with short eye relief, or so similar focal lengths they are kind of redundant. Also cheap zoom eyepieces have several disadvantages.

I would suggest you invest 10-30€ later in an aditional, Good eyepiece, then you are all set. There is nothing wrong with starting with the kit eyepieces only, but for planets and small DSO you will need a bit mor magnification. The mirror quality of the heritage varies, so 260x magnification (w 2.5mm eyepiece) usualy does not work well, requires excelent seeing condtions and collimation. Something around 130-150x is usable regularly.

By the way: Consider buying at teleskop-express.de, they have a Europe price math guarantee, and are a telescope shop with a very good reputation overall.

First buy for a heritage 130p with 650mm focal length:

An Eyepiece for higher magnification, as the low magnification (25mm )kit eyepiece is ok for starters.

Do not buy the Budget Barlows, they reduce the contrast. If you must, the 13 euro seben achromatic barlow works just as well as more expensive ones (20-30 eruro), they look similar and probably come from the same factory in china.

A better ed/APOchromatic barlow will cost as much as two decent starter eyepieces (40-80 + euro). Other eyepieces will outperform the kit eyepiece Plus barlow.

My suggestion

1. High magnification

A) http://m.ebay.de/itm/wide-angle-eyepiece-1-25inches-66-degree-F-6mm-/140717462903

6mm Ultra wide angle 66 degree apparent field of view. 24€ shipped from China (tax may apply, check regulations), 32€ from the UK, 34-40€ from Germany. Including shipping.

One of the best budget eyepieces out there.

On 650mm focal length it will give you 100x magnification, due to the wide angle view, the whole moon will fit into the field of view. VERY nice.

With a 35mm film can you can extend the eyepiece tube in order to reach almost 200x, so for a few cents you have an temporary upgrade and you are able to test how good your telescope is before buying more eyepieces. The modification can be removed or added within a few seconds. Depending on the Film can tube length the heritage may needs to not be extended fully (just a centimeter) in order to reach focus with this modification.

B.) 4-5mm HR Planetary, BST Explorer, TS NED, 40-60€.

Smaller field of view, but very high contrast, sharp image, even at f/5, a little easier to view.

C

Ultra low budget. 9€ 6.5mm Seben/Orbinar plössl. Plössl under 10mm suffer of Short eye relief. The 4mm has such an short eye relief I never use it, it's uncomfortable to use.

I strongly suggest A).

2. Mid range magnicication, 2-3mm exit pupil, ideal for deep sky

After a while you will realize the 10mm is not that good. Solution:

A) A 10-12mm plössl eyepiece for 12€,

B.) or a 12-14mm Erfle 22€ with 70 degree apparent field of view,

C) or a 9/15mm 66deg UWA for 32€.

D) HR-Planetary/BST

Again, D is the best, but the Erfle is a great deal. I have the 12mm. The 66deg UWA are a tad better and have more eye relief, but at f/5, the HR Planetary or BST Explorer wins.

3. Overview eyepiece

The 25mm kit eyepiece is not too bad,

A) but a 30-32mm plössl (16-30€) shows more field. The cheap one lacks an eye cup, can be made of pipe isolation

B.) Under light polluted skies, a 20mm 66deg UWA will show at least as much as the 25mm kit eyepiece, but a darker background, due to the smaller exit pupil.

C) A 24mm wide angle will be the best eyepiece solution but the most expensive one too.

40mm plössl have a small appartent field od view due to the fact the barrel/field stop of a 1,25mm eyepiece limits the size, so it won't show more then a 32mm, plus at f/5, 40mm would provide a too large exit pupil for most human eyes and average sky conditions.

4. Collimation tool to check/adjust the mirror

A) film can or focuser lid with hole - a few cents

B.) Collimation cap, Teleskop-express, 3€ or so

C) Cheshire-sighttube, starting at 20-25€

d) collimation laser, the cheap ones aren't good, really good ones cost 80€.

The heritage has a short tube, the laser is not necessary as you can look through and reach the collimation screws at the same time.

Go with A or B, C if you want.

4. Dimmed Red light

A) red LED bike rear light, under 2€ from eBay international. Solder or stick a resistor between battery and connector, or paint the plastic with permanent marker.

B.) head band lamp with white and red LED, from 3€

c) astro lamp, 10-60€

5.Paper Maps to find deepsky objects (as cellphone displays are never truly black even in night mode, enough glow to ruin your eye's adaption to the darkness)

6. Moon filter

A) Live with the high brightness

B.) sun glasses

D) Cheap green filter from eBay

E) adjustable neutral density / polarisation filter

All work.

So my best-budget eyepiece recommendation for the telescope:

24-32€ 6mm66deg plus film can

22€ 12mm erfle

16€ 30mm plossl, a few euros shipping from seben.de

So this setup costs barely more then the set from amazon, but suits the telescope much better.

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You probably won't need new eyepieces straight away so the best thing is to wait until you have had the scope for a while and see what you need. However, that said a Barlow Lens is usually a good thing to get if your Telescope doesn't come with one.   

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Sorry, but it's not a good idea. I have a 2x and a 3x barlow that are similar to those in such sets. Other then their chromatic abberations, the 10mm eyepiece is pretty low quality. It works, but the details on the planets are much less prominent then with another eyepiece.

And for 24-32€ / 20-27£, you can get a mucj better eyepiece instead of mixing a mediocre barlow with the less mediocre eyepiece, without investing a lot of money :-)

The 10mm with 2x barlow equals 5mm, the 6mm with the very simple to do modification will give you a bit more, ideal for mars, double stars and some nebulae.

The cheap 3x barlow I got (Meade/Bresser) ad even more color fringe.

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The 10mm at 650mm focal length equals 65x magnification (650 devided by 10).

For planets that's a bit low, but you will see that Saturn has rings, and cloud bands on Jupiter if the conditions allow it.

With 6mm you will have 100x, that still is at the low side.

BuT:

You can change the effective focal length of the eyepiece.

It has a glass element in the bottom similar to a barlow (this is also a reason why Barlows sometimes do not work well with some eyepieces, while working with others).

By changing the distance of this glass element to the top part, you can reach 3-4mm (up to 200x)

See pictures at http://stargazerslounge.com/topic/217446-choosing-the-first-telescope-heritage-130-or-virtuoso/

(scroll way down)

A better solution would be a 4 or 5mm HR Planetary or BST explorer, but these cost up to twice as much.

But the 6mm is great for the price.

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