Starting scope advice Celestron Astromaster or Skywatcher?

[CumbrianRed]

Hey, I'm looking for some help on second hand scopes. I've got a terrestrial for bird watching but we've moved to a dark sky zone and I'd love to be able to look at the moon and anything else we can see. Astronomy was always my favourite part of physics and I'd love to get the kids into star gazing too.

I've been looking for good second hand scopes. I seem to keep coming across very small apertures or Astromaster 114s, 127s and 130s, and Skywatcher 150ps and 200ps.

The Astromasters seem to get poor reviews, but are smaller and easy to pack away. The dobsonian seems pretty impractical, but I imagine can see a lot more?

For about the same price would you get an Astromaster 130eq with extra eye pieces or the Skywatcher 200p without any eye pieces or lenses? Keeping in mind I don't really understand what I need to get me started.

Also, is there anything I need to be wary of second-hand are the 130eq or 200p likely to have problems I could/should check for?

Thanks very much for your help!

 

[Ricochet]

2 hours ago, CumbrianRed said:

about the same price would you get an Astromaster 130eq with extra eye pieces or the Skywatcher 200p without any eye pieces or lenses? Keeping in mind I don't really understand what I need to get me started.

Assuming that you have enough in your budget to buy some eyepieces, the 200p dobsonian. It is not a close call at all between the two lines of scopes. The eq mounts bundled with the astomasters mean that despite being smaller they aren’t really any less bulky. Optically, the 200p wins on both aperture and the quality of the mirror(s).

To get started you will need to buy a selection of eyepieces because you can’t use a telescope without an eyepiece. The 200p comes with two focuser extension tubes, one for 1.25” eyepieces and one for 2” eyepieces, so make sure that both are included with the scope that you buy. The finder scope is also a requirement to be able to find anything so check that is included. 

With regards to the condition of the scope have a look at the condition of the mirrors. Check that they aren’t smashed or scratched and that the reflective coating appears to be in good condition. Check that the focuser moves in and out smoothly over its whole range. The base units are made from chipboard like flat pack furniture so check for any obvious damage and that the movement is smooth in both axes.

Additionally, the standard 6/8/10” dobs are too low to observe whilst standing so you will have to also budget for some sort of height adjustable chair. 

The size of these scopes does mean that they are not suitable for carrying up and down stairs, over long distances or on public transport. 

[Mandy D]

@CumbrianRed You should expect to be paying about £200 for a 200P and it should come with two eyepieces and the 1.25" and 2" extensions for the focuser at that price. Nobody keeps those eypieces when they sell these things as they are low end, although acceptable, especially the 25 mm, the 10 mm not so much. As @Ricochet has said the mirrors are excellent. If you are going to store the telescope assembled with the tube upright on the base, the 150P, 200P and 250PX all take up exactly the same floor space of 520 mm diameter. The only real difference in terms of handling is the weight of the OTA (tube) - 150P: 5.3 kg; 200P: 8 .5 kg; 250PX: 12.7 kg. The bases all weigh about 11.5 kg each. So, if you can manage the base, you can probably manage any of the OTAs. I struggle more carrying the base than I do carrying the 250PX OTA, because of it's awkward shape.

Another bonus with these telescopes is that they will all focus with most DSLRs, so you can do basic astro-photography (Moon, bright planets, etc) without buying expensive astro-cameras. I completely agree that you want to make sure the finderscope is included, as it is really not a bad piece of kit and is useful to have. I almost never use mine, though.

Unless you are going to get serious about astro imaging, the Dobsonian mount is very practical and extremely easy to use; much more so than an equatorial mount which will require polar aligning each time you set up.

As Ricochet says, check that everything works smoothly and is in good condition. However, dust on the mirrors is not something to worry about and even small scratches will not degrade the performance noticeably. I have a big (3 - 4  mm) black blob on my primary mirror and it makes no difference to performance. Don't worry too much if you cannot see anything through the eyepiece when you check it, as the mirrors could be hugely out of alignment, but that is very easy to correct. My 200P was bought secondhand and was so far out of collimation (alignment) that I could see nothing through it. 5 minutes with a Cheshire collimator (cheap) and it was working very well, although not perfect.

[CumbrianRed]

Thank you both, that was really helpful. I now have a Skywatcher Classic 200p. I've not had time to test it yet or check all the different eyepieces.

 

[CumbrianRed]

Thank you both, that was really helpful. I now have a Skywatcher Classic 200p. I've not had time to test it yet or check all the different 

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Okay, so I've got a collection of lenses and accessories. A very basic question, what are these best used for and are there any important lenses I'm missing?

 

[Naughty Neal]

Typically supplied Kellner ep's and planetary ep's are low quality and better ep's are usually needed to upgrade for better/sharper seeing/views. But first see how you get on with what you have.

6mm is a planetary high power  lens , 15mm a medium power lense more for general sky work. Typically one needs a low power lens 24mm - 40mm or more for wider sky views,   then   a medium 10 - 15mm or so for  a higher mag on sky objects. 

A high power ep 3mm - 5 or 6mm for close up planetary work mainly the moon. 

 

Most users will have a selection of differing ep's of sizes and brands depending on the target.

At the high power  end one may need 3 or 4 ep's in the 3 - 8mm range or a nice similar range zoom lense , the latter would be inplace of six seperate ep's.

Medium ep's  are a transition ep for viewing objects seen in the wider sky , though typically will be used on planets when high power ep's are too much. The range for medium ep's can be 9mm - 18mm or so, above 18mm  one starts getting into low power ep's for general wider sky views.

 

One also needs to decide  on the format of ep's to buy , does one want to keep to 1.25" ep's or opt for both 1.25 & 2 " ep's. Some have barrel fittings that will suit both but then cost is more for the better ep's.  That said one can get some good ep's that give good results without breaking the bank in the £50 - £100 range.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Edited December 13, 2023 by Naughty Neal

[Naughty Neal]

The Barlows will increase magnificaiton of lower power lenses to higher power but in doing so the view may become less clearer.

For examaple using a 30mm ep,   1.5 x would give you a 20mm ep.

2x  a 15mm ep & 3x a 10mm ep so infect 4 differing magnifications for your 200p. How ever with the current ep's and barlows the views may be poor.

The 6mm ep will give 200x mag , the 15mm 80 x mag and the super 25 48x mag.

 

For magnification one divided the scope focal length /fl with the eyepiece diameter ,  your scope fl is 1200mm/super 25mm = 48x.

Likewise 1200 /6mm = 200x.

The 200x may or may not be the most power one can use in your location at certain times due to atmospheric conditions, at times when the conditions don't allow for good viewing one will have to use a lower power ep to improve the clarity/visibility to try and get through the murk. This is why most users will have a larger selection of ep's /magnifications for the seeing conditions and the subjects they are looking at.

Edited December 13, 2023 by Naughty Neal