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I have a Celestron inspire 90 AZ telescope and I want to upgrade so that I can get a clearer view of the planets and some deep sky watching. I have been looking at the Celestron Astromaster 130 eq or the Skywatcher explorer 150P. I have no experience of reflecting telescopes or equatorial mounts and am a little concerned that they may be a little difficult to use. I am also wondering if either of these scopes are a good step up from my Celestron 90AZ as there seems to be so much to choose from.

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I'm in a similar boat to you, relative newcomer, Sky-Watcher 900mm/70mm refractor on an EQ1 mount. You can actually achieve quite a lot even with a basis but good setup (I've posted a few pics recently).

EQ mounts need a bit of time and patience just to get your head around how they work, but they're really not that hard - I picked it up quickly as a complete novice just by reading the manual plus a couple of web pages.

I recommend you read this article - it's long but worthwhile.

I'm also looking at a Sky-Watcher 130 or 150 Newtonian (the article above suggests you may want to avoid Celestron as they use a spherical mirror rather than parabolic).

What I'm picking up from the folks here is the issue with these bigger scopes is you need a substantial mount to keep it steady - and it's this that pushes up the cost dramatically.

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5 minutes ago, imakebeer said:

I recommend you read this article - it's long but worthwhile.

^^ That is a truly good guide for anyone relatively new to the 'points of light and hazy mist gazing club'!

If constricted via a budget maybe go for an 8- 10", nothing smaller, f5-7 Newtonian optical tube assembly (USED), then make your own Dobsonian mount, should not cost more than 15-20 quid, plenty of articles over the web on DIY.

Maybe at a later date consider an equatorial mount, actually they are NOT hard to make....

Avoid anything with a 'spherical surfaced mirror', no other comments from me regarding that particular issue as previously I sent the natives into a frenzy daring to suggest that a scope with a spherical mirror is junk....

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There are lots of similar posts on the forum so its worth browsing or searching and reading up on suggestions etc they cover.  The problem is that you will never find a scope that covers all the bases.   To resolve more detail in the planets you need aperture and focal length, this is why a lot of the images that grace the covers of magazines that have been taken by armatures have used 12" or 14" F20 Cassagrain or Mac's.   When it comes to faint deep sky objects the opposite is true.  A large aperture but fast scope with a short focal ratio of F5 or less.

Out of the two you list I would opt for the Explorer 150.  If you are considering connecting a camera at a later stage then the PDS version would be a better bet.  Place this on an EQ3 or better still an EQ5 and you'll have a rig that will cover for any future ventures into astrophotography should you later wish to go down the road.  The EQ5 will have a greater load carrying capacity, and provide a slightly more stable platform for the scope.

EQ mounts are not that daunting.  They are basically an Alt/Az mount tilted to match the latitude from where you are observing.  Granted the eyepiece can get into some funny positions when using a Newtonian reflector, but there are ways to overcome that without upsetting the balance of the scope.

Anyway, that's my 2p worth.... 

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3 minutes ago, malc-c said:

When it comes to faint deep sky objects the opposite is true.  A large aperture but fast scope with a short focal ratio of F5 or less.

Is it fair to say that if you went for such a scope, F5, you could add a Barlow to increase focal length for planetary work?

Or is it not as simple as that / is this rookie missing something?

(Which is not to say that a dedicated longer focal length scope wouldn't be more optimum for planetary)

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1 minute ago, imakebeer said:

Is it fair to say that if you went for such a scope, F5, you could add a Barlow to increase focal length for planetary work?

Or is it not as simple as that / is this rookie missing something?

(Which is not to say that a dedicated longer focal length scope wouldn't be more optimum for planetary)

Yes you can use barlow lenses to give effectively double or triple the focal length.  I've stacked two 2x barlows with my 200P and taken an image of Jupiter.  The result was OKish, but the resulting 200mm F20 combination the image was quite dark and needed stretching a lot in post processing.  Part of the problem is that every time the light from the target passes through glass it degredates the image a little.  So in order to compensate that you really need high quality barlow lenses which are not cheap because they use better quality optically graded glass that gives less chromatic aberration.   

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A true Cassegrain is a 'sorta' all round scope with an f4 Newt and f16 Cass focus. Not sure if anyone makes them these days. If they are commercially manufactured they won't be cheap (if they are PROPERLY made).

🙂 I better not suggest you make your own Cassegrain as I got into deep trouble with some of the 'natives' for even suggesting making your own Newt mirror 😞 

PS I would not actually encourage anyone who has not made less than a dozen Newt mirrors to even contemplate making a Cass

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1 hour ago, SthBohemia said:

I sent the natives into a frenzy

 

23 minutes ago, SthBohemia said:

I got into deep trouble with some of the 'natives'

Perhaps if you were less insulting and negative you could avoid such situations.

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I haven't read the entire article, but I'd have no worries about buying a F10 Newtonian and expecting it to work perfectly, which it will providing there's no turned edge, zones, and has a perfectly flat secondary. Parabolizing an F10 mirror offers no meaningful advantage other than to significantly increase the cost of production. 

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17 minutes ago, mikeDnight said:

Parabolizing an F10 mirror offers no meaningful advantage other than to significantly increase the cost of production. 

Half true, it increases production costs significantly, especially as reading the faint shadows cast when testing f10-f12 newt mirrors is an absolute PAIN 😞 

An f10 newt left spherical at f10 can be considered as 1/4 wave to 1/2 wave accurate. Guess it all depends on how accurate you desire the mirror to be. 🙂 a Questar or a SW??

Ammendment.. Theoretically a newt mirror left spherical can be considered as a whole wavelength out 😞

 

Edited by SthBohemia
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6 hours ago, SthBohemia said:

🙂 I better not suggest you make your own Cassegrain as I got into deep trouble with some of the 'natives' for even suggesting making your own Newt mirror 😞

It’s about being appropriate to the thread subject as much as anything. A new starter asking about the choice between two scopes is highly unlikely to start off by making their own dob including grinding mirrors. With decent kit available at reasonable prices now, there is no need as there might have been in the sixties. 

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My comments regarding, 'make your own', are, I suppose, aimed at anyone who wishes to have an instrument of known quality. I doubt if many of the commercially available mirrors have anything even approaching the optical quality of those I hand polish. When final stages of figuring entail 30 seconds of polishing, a cooldown (pyrex) of 15 -20 minutes, testing, then back to figuring repeatedly- until all zones of the mirror decide to behave... Imagine the cost of finished scopes if that procedure was followed by the 'popular' manufacturers 😞 

Finished mirrors and scopes were available during the 60's, there were 2 suppliers within Oz alone, let alone the suppliers within USA- Cave, Coulter, Edmunds etc. maybe just a generation of 10 gap? Different attitudes? Maybe we old fools were somewhat more self reliant than the kids of today....

 

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13 hours ago, SthBohemia said:

My comments regarding, 'make your own', are, I suppose, aimed at anyone who wishes to have an instrument of known quality. I doubt if many of the commercially available mirrors have anything even approaching the optical quality of those I hand polish. When final stages of figuring entail 30 seconds of polishing, a cooldown (pyrex) of 15 -20 minutes, testing, then back to figuring repeatedly- until all zones of the mirror decide to behave... Imagine the cost of finished scopes if that procedure was followed by the 'popular' manufacturers 😞 

Finished mirrors and scopes were available during the 60's, there were 2 suppliers within Oz alone, let alone the suppliers within USA- Cave, Coulter, Edmunds etc. maybe just a generation of 10 gap? Different attitudes? Maybe we old fools were somewhat more self reliant than the kids of today....

 

I have no doubt that you and many other amateur mirror makers are capable of spending the time and effort to produce very high quality results. All power to your elbow.

Your comments however reinforce the fact that a new starter in the hobby is highly unlikely to have the time, tools or skills to be able to build a scope from scratch. You seem unaware of the fact that modern mass produced scopes are of a very good and constant quality, and are affordable. I’m sure finished mirrors were available back in the 60s, but at considerable expense so it does not bear comparison.

You say you don’t insult people, but your implication is that people today have a poor or lazy attitude. Actually people with limited time due to family, work or other commitments just choose to save time by spending money on a good finished scope so they can actually get out there and enjoy astronomy.

A reminder. We are now in 2022.

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Can we get this thread back on track.  The OP asked for opinions on two scopes which they wanted to use for  viewing both planetary and deep sky objects.  They have since opted for the SW Explorer 150P, which I'm sure will suit their needs until such a time where they may want to invest more time, energy or money and upgrade to something else.  At that time they may have the inclination to try the DIY route and build their own scope (bearing in mind that DIY is not just about grinding a mirror).

We are spoilt for choice these days, with several manufactures offering a multitude of telescopes at various price points to cater for both the casual beginner, through to serious amateur.  Often this can make choosing a suitable model difficult as there is so much to choose from.  Regardless of the model chosen, modern manufacturing techniques mean that the optics are finished to a degree that enables the scope to perform within its expectations.   I think that most of us lack the ability to visually detect if a mirror is finished to 1/10th wave or 1/4th wave, and will be happy with a commercial scope so long as the scope produces a decent crisp image. 

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6 minutes ago, malc-c said:

Can we get this thread back on track.  The OP asked for opinions on two scopes which they wanted to use for  viewing both planetary and deep sky objects.  They have since opted for the SW Explorer 150P, which I'm sure will suit their needs until such a time where they may want to invest more time, energy or money and upgrade to something else.  At that time they may have the inclination to try the DIY route and build their own scope (bearing in mind that DIY is not just about grinding a mirror).

We are spoilt for choice these days, with several manufactures offering a multitude of telescopes at various price points to cater for both the casual beginner, through to serious amateur.  Often this can make choosing a suitable model difficult as there is so much to choose from.  Regardless of the model chosen, modern manufacturing techniques mean that the optics are finished to a degree that enables the scope to perform within its expectations.   I think that most of us lack the ability to visually detect if a mirror is finished to 1/10th wave or 1/4th wave, and will be happy with a commercial scope so long as the scope produces a decent crisp image. 

Thanks Malc, but no time to read it, just found a bucket of sand so off to melt it down into glass. Now if only I could remember where I left my notes on how to make Aluminium...... 🤣

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1 minute ago, scotty38 said:

Thanks Malc, but no time to read it, just found a bucket of sand so off to melt it down into glass. Now if only I could remember where I left my notes on how to make Aluminium...... 🤣

😂  🤔

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I agree  on that you have told;  in the 60s in Italy (for exemple) an acromat 60/700  costed  as a clerk salary,  it was most advantageus  constructing it. Today the prices are much lower, so it better buying it; if one has the hobby of optical-mechanics it is different because constructing of telescope will give him a lot of gratification but he doesn't spend less.

Edited by Gonariu
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  • 1 month later...

Got my new Skywatcher 150 P and I'm really happy with it. Got some good views of Jupiter and its 4 main moons last night so I'm delighted with my choice. I know the eyepieces that come with it are reasonably good but could someone recommend decent quality eyepieces and maybe a good quality Barlow lens.

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1 hour ago, Mdennis said:

Got my new Skywatcher 150 P and I'm really happy with it. Got some good views of Jupiter and its 4 main moons last night so I'm delighted with my choice. I know the eyepieces that come with it are reasonably good but could someone recommend decent quality eyepieces and maybe a good quality Barlow lens.

I have the RVO 2" Barlow. It is fairly lightweight and comes with a reducer to 1.25" for not a lot of money. It seems to have a good reputation in here and it works well in my 200P and RC6, although I prefer my Explore Scientific focal extender, but that is nearly four times the price.

https://www.rothervalleyoptics.co.uk/rvo-x2-ed-barlow-lens-2-with-adaptor.html

For eyepieces, I like the Baader Hyperion, but everyone has their own opinion on this topic, so I'll leave it at that.

Edited by Mandy D
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2 hours ago, Mdennis said:

Got my new Skywatcher 150 P and I'm really happy with it. Got some good views of Jupiter and its 4 main moons last night so I'm delighted with my choice. I know the eyepieces that come with it are reasonably good but could someone recommend decent quality eyepieces and maybe a good quality Barlow lens.

Good choice, it's a pretty capable scope. I have the Heritage version, same mirrors. How much do you want to spend? Usual recommendation is BST Starguiders, around £55 apiece. Your scope is fairly "fast", so the best BSTs are likely 15/12/8/5mm although  you can get away with fewer, say 12 & 8mm plus Barlow (there's a 2x in the same BST range). The 5mm will also work well but the 8mm + Barlow would probably be just as useful.

I'd suggest a 32mm Plössl as a lowest-power, not expensive and it'll work just fine, Barlow it for an effectively-16mm. EDIT: might give too much eye-reliew Barlowing a 32mm Plössl, try it though.

If your budget is more generous, look at OVL's Nirvana range. Much wider and also good value step-ups, I have a 16mm and it works well so I'd expect the others would too. EDIT2: 16 & 10mm and a 2x Barlow would give useful choices in Nirvanas.

Edited by wulfrun
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Congratulations on the new scope @Mdennis the planets are a great place to start 👍 it all went a bit south for a minute there but don't let that put you off, it's usually really friendly in here, other forums may vary

I'd certainly look at a 32mm plossl to start with, wide field and will give good results 

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If you can afford it I would target a 24mm 68° eyepiece for your lowest power/finder as this will give a darker background sky than a 32mm Plossl whilst showing approximately the same true field (5mm exit pupil vs 7mm). This will have the most effect if your skies suffer from any light pollution. Depending on your budget the options suitable for an f5 telescope are the Ultra Flat Field (UFF), of which I believe the Stellalyra is the current cheapest branding, the Explore Scientific 68°, or the Televue Panoptic. 

Alternatively, in a dark sky location a 7mm exit pupil might be ok in which case the 30mm UFF might be a better low power option if it is within your budget and your 150p has a 2" focuser.

As suggested above, the 12/8/5mm Starguiders work well at f5 and can be had relatively cheaply, but do not have enough eye relief if you need to wear glasses while observing due to astigmatism. An idea of your budget would be useful as other suitable eyepieces would be the Nirvanas, Explore Scientific 68/82/92°, UFFs, Vixen SLV, Baader Morpheus, Pentax XW, Televue (all ranges) and there is a significant cost difference between the cheapest and most expensive options.

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22 minutes ago, Ricochet said:

 

As suggested above, the 12/8/5mm Starguiders work well at f5 and can be had relatively cheaply, but do not have enough eye relief if you need to wear glasses while observing due to astigmatism. An idea of your budget would be useful as other suitable eyepieces would be the Nirvanas, Explore Scientific 68/82/92°, UFFs, Vixen SLV, Baader Morpheus, Pentax XW, Televue (all ranges) and there is a significant cost difference between the cheapest and most expensive options.

I have the 12mm & 5mm Starguiders and often wear glasses when observing. I’m very short sighted and have some astigmatism, although to be honest I don’t really notice it when not wearing glasses. My daughter always prefers to observe wearing glasses, so any issues and I soon know!

We both find that the 12 & 5mm Starguiders have adequate eye relief. And You can effectively get more by removing the large rubber eyecup (easy on these) which I find a little annoying when wearing glasses anyway - the rubber is a bit too solid for my liking with a spectacle level pressed against them. 

Edited by PeterStudz
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24 minutes ago, PeterStudz said:

the rubber is a bit too solid for my liking with a spectacle level pressed against them. 

Yes, this is why I said the eye relief is not really enough. I found that they pressed my glasses into my face which was not comfortable. For people with slightly less deep set eyes perhaps the eye relief is adequate.

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