First telescope

[Cohhul]

Hi,

I am living over in Vietnam where the sky is pretty polluted but I'm looking to buy my first telescope. Looking at the moon and it's craters will be the main use. A friend had a basic one whilst he was living here and it was also fun to zoom in at bright dots throughout different districts to see shop signs.

I heard that a Dobson is better for viewing the night sky but a refractive one could be better for my location.

The scopes that are over here are pretty limited but I was looking at the Meade LightBridge Mini 82 (Dobson) or the CELESTRON SCTW-80 (Refractive).

As a beginner I'm not sure which would be best for me to purchase. Thanks for your help in advance.

 

Cathal

[Zermelo]

Hi Cathal, and welcome to the forum.

If you are in a light polluted area, then it's lucky that your main target is the moon, which won't be badly affected.
How important is the terrestrial use (shop signs, etc.) to you? That may push your choices in certain directions.

Also, do you have a maximum spend in mind?

[Cohhul]

Thanks for your reply!

If moon gazing out of the Dobson allows me to see craters and the surface of the moon much more clearly then I am willing to sacrifice the terrestrial use. I would love to spend a lot but I am only a temporary resident here in Vietnam and transportation would be an issue if I spent big and I also have other career paths (Music Production) to waste my income on  I'm willing to spend around 200USD but as I said there aren't many outlets for purchasing here (We don't have Ebay or Amazon) just some Viet traders and these two seemed the best of what is available around my price range (Meade LightBridge Mini 82 (Dobson) or the CELESTRON SCTW-80 (Refractive)) from my short reading I am to the understanding the the bigger the diameter the more light becomes available to gaze further/more clearly.

I live in Ho Chi Minh city and it's heavily polluted here but we have the chance to see a lot of beautiful blood moons that I didn't see growing up in the UK. I need something potable to take on short trips out of the city here.

I appreciate your help and interest.

 

[Tiny Clanger]

9 minutes ago, Cohhul said:

Thanks for your reply!

If moon gazing out of the Dobson allows me to see craters and the surface of the moon much more clearly then I am willing to sacrifice the terrestrial use. I would love to spend a lot but I am only a temporary resident here in Vietnam and transportation would be an issue if I spent big and I also have other career paths (Music Production) to waste my income on  I'm willing to spend around 200USD but as I said there aren't many outlets for purchasing here (We don't have Ebay or Amazon) just some Viet traders and these two seemed the best of what is available around my price range (Meade LightBridge Mini 82 (Dobson) or the CELESTRON SCTW-80 (Refractive)) from my short reading I am to the understanding the the bigger the diameter the more light becomes available to gaze further/more clearly.

I live in Ho Chi Minh city and it's heavily polluted here but we have the chance to see a lot of beautiful blood moons that I didn't see growing up in the UK. I need something potable to take on short trips out of the city here.

I appreciate your help and interest.

 

I love my heritage150 dob, but I think from what you say a dobsonian would not be a good choice for you. It sounds as if you really want something very compact and portable, the advantages given by a newtonian telescope (dob.s are a subset of newtonians , having a specific type of simple base) are all to do with them having a big mirror, which means a big tube, which means a heavy strong support ...

A refractor or a maksutov will be more compact light and transportable. When I was thinking about buying a telescope to supplement my dobsonian I read this detailed account of a small 'scope which might be a good match for your requirements

http://www.waloszek.de/astro_sw_mak102_e.ph

It costs under £200 in the uk, for example https://www.firstlightoptics.com/maksutov/skywatcher-skymax-102-ota.html

There is also a smaller version for £130 https://www.firstlightoptics.com/all-telescopes/skywatcher-skymax-90-ota.html

That's 'OTA' i.e optical  tube alone , no support, but it looks from the other link as if a camera tripod (easy to buy and transport,relatively inexpensive ) may well be sufficient to hold it. A proper alt az mount ( cheapest about £100 ) would be better and allow fine adjustment though.

I have not researched into refractors, so can't comment on those, I'm sure someone else will .

Good  luck with your search, and eventual viewing

Heather

[Cosmic Geoff]

The Moon looks great through any telescope. What you buy will depend on what's available to you, and your personal preference.  Try to avoid very small Newtonians with short focal ratios and spherical mirrors, e.g. f4 as they will not perform well.  I do not recommend the Meade.  For looking at the Moon the type of mount is not that critical so long as it is not excessively wobbly.  If you are looking at scopes of 80mm aperture, a refractor may make more sense.

I don't know about the Celestron as this exact model is not available in the west.  It looks like a rather basic model.

A small Maksutov would also prove practical.   If terrestial use is a consideration, look at the class of telescopes called "spotting scopes" as they could fill both roles.  You can also use an astro scope on terrestrial targets so long as you don't mind the image being upside down or laterally flipped.

Edited December 4, 2020 by Cosmic Geoff

[Zermelo]

3 hours ago, Cohhul said:

Thanks for your reply!

If moon gazing out of the Dobson allows me to see craters and the surface of the moon much more clearly then I am willing to sacrifice the terrestrial use. I would love to spend a lot but I am only a temporary resident here in Vietnam and transportation would be an issue if I spent big and I also have other career paths (Music Production) to waste my income on  I'm willing to spend around 200USD but as I said there aren't many outlets for purchasing here (We don't have Ebay or Amazon) just some Viet traders and these two seemed the best of what is available around my price range (Meade LightBridge Mini 82 (Dobson) or the CELESTRON SCTW-80 (Refractive)) from my short reading I am to the understanding the the bigger the diameter the more light becomes available to gaze further/more clearly.

I live in Ho Chi Minh city and it's heavily polluted here but we have the chance to see a lot of beautiful blood moons that I didn't see growing up in the UK. I need something potable to take on short trips out of the city here.

I appreciate your help and interest.

 

OK, so we are living in strange times. In previous years you might get several people making various suggestions and giving their reasons, then you could make your choice, and then look around for the best price. But Covid has turned that around, because of the lack of stock. Once you have a reasonable idea about your needs, see what's actually out there that might fit - which you have done. And your location is also going to be a factor, as I doubt there are many here who know the local market any better than you do already. So I'm afraid I'm going to make some general comments rather than specific recommendations. More experienced commentators may be less cautious than me.

So, your suggestion the Celestron SCTW-80 is an F/5, 80mm achromat refractor. 80mm is a reasonable aperture for a starter scope. It's certainly portable, meeting your need, and the bundling of a smartphone holder and backpack suggests that it's aimed specifically at that niche. The tripod is possibly a little flimsy from the photo, though the telescope tube is light and short so it may be OK. I don't have any experience with that model, others may have opinions. You may find that it's not so steady at the highest magnifications (by the way, ignore the claim of a maximum mag of 189x, I'd say 120 under ideal conditions).
Something else you should be aware of is the likelihood of chromatic aberration (coloured fringes on the images you see). This is an effect in all refractors to some extent, though it's more obvious in simpler 2-element designs like this one. The fact that it's a "fast" (short) refractor will increase the effect. On some targets you may not notice the fringes, but they are most obvious on the brightest objects - and your main subject is to be the moon. If it's really bad, it will start to affect the detail you can see. So if you go for a refractor you might want to consider a "slower" model, perhaps F/8 or even F/10 (if the spec doesn't say, you can work out the focal ratio by dividing the focal length by the diameter of the objective lens). The down side is that it won't be quite as portable; you could compromise by looking for a decent 70mm instead, which would improve your focal ratio and portability, and perhaps not lose much in terms of light grasp, if the moon is the main target.

As the others mentioned, a Mak (Maksutov-Cassegrain) device would be very compact, and have a long focal ratio that would give you higher magnifications without much of the distortion of a short refractor. However I think you will struggle to find much that is reasonable under USD200. Possibly this one if you can find it? The Dobsonian reflectors are generally the best value, though it's true that they will be less portable than the Maks or refractors. But you can get some that collapse to a smaller size.

If you feel confident enough, you should consider buying something second hand, for two reasons: you will get a more capable item for your budget, and the current supplier shortages won't be such an issue. 

 

 

 

[KP82]

I agree with the others a small 4 - 5" mak is probably your best option.

That Celestron refractor looks very much like the Skywatcher Startravel 80. It's ok for widefield sweeping of the night sky and terrestrial viewing, but will struggle with high power lunar and planetary views due to strong CA.

[pregulla]

I wouldn't recommend either of these 2. 82mm Lightbridge has very fast shperical mirror - which mean it has not so great optical qualitry and very large central obstruction (secondary mirror covering large part of the aperture). CELESTRON SCTW-80 is very short achromatic refractor, it will show a lot of chromatic aberration at higher powers. The Moon will probably be bearable, but the planets will be colorful disks. It also seems to come on photo tripod - winch will make it very shaky and frustrating to use for anything other than lowest powers.

If you want to spend minimum amount of money possible I would recommend 70mm F/10 achromat. It will have very little chromatic aberration and will perform much  better than the two you have suggested. If you can stretch you budget a little more I would highly recommend getting something like SkyWatcher Heritage 130p or other 130mm table top dob.

Edited December 5, 2020 by pregulla

[Cohhul]

Thanks so much for everyones feedback.

I am planning to make a purchase on Monday. Based upon what people have said I have whittled it down to these few here...

Calstron 80EQ Deluxe 290USD

Calstron C90 Mak 280USD

Meade Polaris D80F900 EQ 300USD

SkyWatcher 90 EQ2 300USD

 

Would anyone care to share their opinion about these? Once again thanks for the help here. I didn't expect forums to be so helpful

 

[Tiny Clanger]

19 minutes ago, Cohhul said:

Thanks so much for everyones feedback.

I am planning to make a purchase on Monday. Based upon what people have said I have whittled it down to these few here...

Calstron 80EQ Deluxe 290USD

Calstron C90 Mak 280USD

Meade Polaris D80F900 EQ 300USD

SkyWatcher 90 EQ2 300USD

 

Would anyone care to share their opinion about these? Once again thanks for the help here. I didn't expect forums to be so helpful

 

Some of those names can apply to more than one telescope, as the 80 or 90 is the diameter of the optics . best give a full name or a link to get accurate responses, for instance I looked up 'Calstron 80EQ Deluxe' and got results for Celestron PowerSeeker 80 and Celestron AstroMaster 80 , two different telescopes entirely. You don't want advice based on the wrong product !

[Cohhul]

Ahh right maybe if I post links you can see further.

The Celestron 80EQ Deluxe refractive telescope is an upgrade to  the Celestron PowerSeeker 80EQ Refractive Telescope  - 

https://shopthienvan.net/kinh-thien-van-khuc-xa-celestron-80eq-deluxe-id274.html

Celestron C90 Mak Spotting Scope

https://shopthienvan.net/kinh-thien-van-celestron-c90-mak-spotting-scope-id235.html

Meade Polaris

https://thegioithienvan.com/san-pham/kinh-thien-van-meade-polaris-d80f900-eq/

Skywatcher 90EQ-2

https://thegioithienvan.com/san-pham/skywatcher-90eq2/

 

[Cohhul]

I think I will go for the Celestron C90 Mak just because of the size and it still looks to have great quality. I've been reading that the finder scope and 45 degree angle isn't ideal.

Are there any upgrades that you would recommend?

Thanks again

[Cosmic Geoff]

The Celestron, Skywatcher  and Meade refractors would probably suit you, being 'classic' long focal ratio achromatic refractors.  The mounts are likely to be wobbly, but there is not much you can do about that with your budget. And you will need to know how to set up an equatorial mount to get the best out of it.

I would issue a cautionary note about the C90 spotting scope.  This is designed to be a low-power terrestial scope, and though it can be turned on the night sky, you should confirm that the eyepiece can be swapped with higher power 1.25" (31.7mm) barrel size eyepieces.  The 45 deg erecting prism may not be the best for high power astronomical use and I suspect you cannot swap it out.  In short, a Maksutov supplied for astronomical use with a 90 degree digonal would be better.  And is a mount and tripod included in the deal?

Edited December 6, 2020 by Cosmic Geoff

[Cohhul]

 What started out as a cheap deal is turning to be expensive haha. The size and portability of it now are becoming the main reasons to buy. 

I am thinking of getting the C90 scope. A Barlow x2 lens, 90 degree diagonal and a 10mm eye piece. Do you think those 3 add ons are worth investing in and is the 10mm the best eye piece to buy? (it comes with a 32mm)

I will need to buy a Tripod too which seems costly. Buying a Benro T880EX was suggested (although not ideal it could do the job)

Thoughts on the above?

[Cosmic Geoff]

36 minutes ago, Cohhul said:

I am thinking of getting the C90 scope. A Barlow x2 lens, 90 degree diagonal and a 10mm eye piece. Do you think those 3 add ons are worth investing in and is the 10mm the best eye piece to buy? (it comes with a 32mm)

You don't know if the diagonal can be exchanged. Probably not.

Which 10mm eyepiece? Unless you specify one, we can't comment. We don't know what is available in your country. But 10mm would be a useful focal length of eyepiece.

A Barlow lens should be useful.

[Tiny Clanger]

I endorse everything Cosmic Geoff said above .

Be absolutely certain that you can change the 45 degree prism on the C90 and that it can take standard eyepieces , much better to try and track down the model intended for astro use rather than waste money trying to make the spotter scope what it isn't.

The mak is not big or heavy, so any decently made photo tripod which is tall enough should be fine . Benro used to be top of the range and expensive decades ago, I've no idea if they still are, I seem to recall the original specialist company and brand name name got sold . Don't bother with exotic lightweight tripods unless you are hiking up mountains, a heavy cheap basic model will be fine. Try to find something with minimal plastic and thick metal tubes , the heavier and chunkier it is, the more stable a platform it will be. If you can get it to around head height without extending the central column much (which will add wobbles) even better.

[Cohhul]

This is the 10mm eyepiece I was looking at - https://www.lazada.vn/products/thi-kinh-10mm-truong-rong-62-celestron-aspheric-i818190389-s2235870230.html?exlaz=d_1:mm_150050845_51350205_2010350205::12:1497503216!59440595164!!!pla-293946777986!c!293946777986!2235870230!128141203&gclid=CjwKCAiAn7L-BRBbEiwAl9UtkBk9tGwR4U65FmZsF3ghTCdOCkkKm8ZMO93Eue6DLxTZBGUA73FUOxoCoagQAvD_BwE

I have been reading forums of users with the C90 and they have said that they have upgraded to a 90 diagonal so it is possible.

Thanks for the info about the tripod. The C90 is 2.3kgs so I will find a tripod that supports it.

I was wondering if any other mm eyepiece would be worth investing in? I don't know much about what they do. I just saw someone saying a 10mm with a barlow could be too much and a 25mm could be better?

Spec for eyepiece translated - 

Brand: Celestron, Aspheric series
Focal length: 10mm
Standard: 1.25 inch (~ 31.7mm)
Field of view (FOV): 62 degrees
Laminated glass: Plossl
Coating: multi-layer (fully coated)
Weight: 50g
Eye cushion rubber: Yes
Highlights: large focal length, wide suitable for observing nebulae, star clusters, ... With anti-slip lock groove when mounted on telescopes, natural rubber night eye for comfortable viewing comfortable for a long time

 

[Cosmic Geoff]

I have no idea how that 10mm eyepiece compares with others. Ideally you want several eyepieces to give a range of magnifications depending on what you want to look at, the seeing conditions and how much you want to get in the field of view. In the UK one would look at the Celestron Omni for lower powers and more complex eyepieces for higher powers. The choice is immense. 

It does appear that the diagonal can be swapped out.

[Second Time Around]

You don't have to restrict yourself just to the craters on the moon even though you live in the city.  I don't know how bad your pollution is but I expect through a telescope you'll be able to see bright planets such as Venus, Mars, Jupiter and Saturn.  You may be able to see some objects such as star clusters and the Orion Nebula.

However, the problem is likely to be finding objects that you can't see with the naked eye.  This 80mm refractor on an altazimuth mount and tripod (costing 5.500.000 ₫  from your local store) may be the answer: https://thegioithienvan.com/san-pham/kinh-thien-van-khuc-xa-starsense-explorer-lt-80az/

Starsense Explorer works in conjunction with almost any modern smartphone.  The phone takes a photo that will show many more stars than are visible with the naked eye.  It then compares the position of these stars with it's database to work out where your scope is pointing.  You then enter the object you want to see and the technology shows on a map on the screen which way to move the scope.  Once found a green circle is lit up.

I've just bought two of my grandkids the smaller 70mm version for Xmas.  This is available only in Europe.  The reason I chose it is that they live in central London, that is pretty light polluted although possibly not as bad as where you are.

This new Starsense Explorer technology is a real game changer in such circumstances.  In fact, I was so impressed I bought the same scope for myself!  Although I live in the country I've adapted the Starsense Explorer so that I can transfer it to any of my scopes.

P.S. You can also use this scope down on the ground as it comes with a 90 degree star diagonal that gives an erect image.

[Tiny Clanger]

Get the scope , use it a bit, see if the included eyepiece is enough for your needs before buying extras.