Which 3rd telescope? i am confused.

[prabal276]

hello,

greeting from India.

i am going to buy a third telescope. there are two or three options available with me:-

1)  Celestron 31145 NexStar 130 SLT  or  celestron nexstar 4se

2} 8 inch/10 inch orion dobsonian telescope

i am preffering a automated telescope 1) as here the skies are light polluted and i have trouble locating objects with my telescope. not much time is left then(schoolwork).i want to see morecelestial objects

  

which according to your opinion is the best telescope for me(intermediate astronomer)

THANKS

[michael.h.f.wilkinson]

I see from your sig (difficult to read on my monitor in that colour) that you have a 60mm scope and a pair of binoculars. The NexStar 130 SLT will show more than the 4SE, although I have heard the 4SE has the slightly sturdier mount. I do not know if it is possible to escape the light pollution by travelling out of town, in which case a compact scope has the edge over an 8-10 dobson. In terms of the detail shown, the Dobson will win on all fronts. My own 8" scope is operated from my back garden, which is quite dark by suburban standards, but still suffers from light pollution. I was more-or-less resigned to looking at planets and the moon, but as I tried pushing the boundaries I found that many more DSOs can be found from my garden, and indeed most of my galaxy hunting has been done from my garden. My scope is also not automated, but equipped with a big finder I have been able to track down a lot of objects (800+). I have been to several star parties where I had found at least half a dozen objects by the time the goto scopes had finished setting up. Goto is a great tool, but for quick sessions, non-automated scopes (or binoculars) are better.

[prabal276]

thanks for your advice sir 

but i believe that i would be travelling out of city once in a while(3-4 months). for The non automated part your talk is true it is set up easily but my problem is that that i have problem finding dso's because the light pollution washes away the finder stars. if i start finding the finder stars it would be time consuming.). here in new delhi some 3-4 stars are visible so that would be enough for the automated one to align itself and then start whirring away.... finding objects. or i could take one of the orion intelloscope dobsons(they do not find the object but just guide you to it)

whats your opinion now???

[Qualia]

If you can afford it, have room for storing it and know that it won't become a bother to set up and give collimation a little tweak each night, I'd go for the biggest aperture newt-dob you can afford. The 10" sounds perfect

Nevertheless, regardless of aperture, your astronomical enemy is light pollution. By analogy, using a scope in horrid city skies is a bit like listening to music with a drill going on in the background. Sure, you'll hear the loud bits, but the fine melody and subtle cadences are going to be lost.  So, if it is possible, try to figure out where you could successfully view from to eliminate some of that slow glow. It could be your garden, or it may mean a trip out of town.

Nothing really beats dark skies, and my heart tells me it would be better to save your money and put it towards transport fees and take your 5" out to dark skies once or twice a month, rather than viewing from a city centre with a 10" every night.

Of course, the best would be reasonably dark skies and the 10" , so you might want to look into portable truss designs etc.

[Owmuchonomy]

Michael will answer I'm sure but I would just reiterate the issue with light pollution.  The main concern for me would be that even if you pointed the scope in the right place then the LP will be too much for a decent visual experience.  Certainly for the Dobsonian, it would not be able to take advantage of its better light gathering capability in such a situation.  There is no substitute for a darker sky I'm afraid.

[Charic]

thanks for your advice sir 

but i believe that i would be travelling out of city once in a while(3-4 months). for The non automated part your talk is true it is set up easily but my problem is that that i have problem finding dso's because the light pollution washes away the finder stars. if i start finding the finder stars it would be time consuming.). here in new delhi some 3-4 stars are visible so that would be enough for the automated one to align itself and then start whirring away.... finding objects. or i could take one of the orion intelloscope dobsons(they do not find the object but just guide you to it)

whats your opinion now???

If the light pollution is so bad, the telescope won't magically make everything appear in the night sky,  evem witj GoTo, although a telescope is designed to capture more light than eyes alone!

[prabal276]

sometimes the skies are clear enough to reveal 40s or 50s of stars here plus i would be travelling out of the city once or twice in a while. well the 5'' would be much more portable. 

if you leave the light pollution, which of the telescopes would you prefer? (portability should also be considered).any one of you have the celestron nexstar 130slt would the views be nice?

[LukeSkywatcher]

I dont know why i find myself agreeing with Michael almost 100% of the time when he comments (well i do really). 

A Go-To scope will not overcome light pollution in itself. In fact, no scope will overcome light pollution without the aid of a light pollution filter or travelling to a location with no light pollution. An 8-10 inch Dob scope would be the best option because it is the cheapest way to get the biggest aperture (light gathering) scope. 

A happy medium, which will give you both big aperture and Go-To is the Celestron 8SE. Its easy to transport to a dark sky location or you can add a light pollution filter to is and you really are good to go.

It really all depends on the level of light pollution, which i am guessing in any big city in India is pretty bad.

[trazor]

I see from your sig (difficult to read on my monitor in that colour)

Just highlight it, as though you were going to copy.

[JRWASTRO]

Greetings Prabal276,

Cannot help but agree with the thrust of the arguments thus far. A 10" dob is a very nice instrument.  I have a Skywatcher collapsible 10" dob as a grab and go scope. The main thing is that this is a large instrument and quite heavy and when dismantled for transportation takes up quite a bit of room.  When I use it as a portable instrument I carry quite a bit of ancillary gear like batteries (large enough to last the viewing session) collimator, eyepieces, filters, star atlas, viewing plan (perhaps a laptop) cables, gps unit, spirit level, compass (suitably corrected magnetic one) and just in case,  gaffer tape (fixes anything) suitable tools spare car keys (round my neck!!) , drinks, some food , insect repellent etc. etc.  etc.   So you will need suitable packaging/boxes.

Jeremy

[nicoscy]

Unless you are willing to travel to a dark site, given your skies you will not get the results you want. You can do lunar, solar, planetary and double star work from home.

Therefore you need to decide on priorities, i.e. travel to dark site to see DSO or watch from your back yard?

If it will be the back yard, then the biggest aperture you can manage for DSO and that again will be a very limited viewing unless you focus on unar, solar, planetary and double star work

[prabal276]

well,according to all of you i need to get the biggest aperture dobson i can. right?

can i go for the orion 8i/10i intelloscope dobsonian which would complete both the matters.

is it prefferable????

[nicoscy]

If you will use the scope exclusively from your back yard which is as you say severely light polluted and no trips are planned to dark sites, then yes, biggest dobsonian you can get if you want to have any success with the DSO that it is possible to see from your location.

Word of warning: Despite the large aperture, under severe pollution your choices for DSO are pretty limited to most M objects and a few NGC and that's it. Nothing beats dark skies. But don't buy blindly based on what we recommend here. Any other amateur astronomers or astronomy clubs close by in India? Nothing beats a hands-on experience to make up your mind.

[prabal276]

i will surely travel to sites outside town but i only want to see the messier catalog and solar system perhaps one or two ngc's

[nicoscy]

Then get the large Dob. But you will get bored after exploring the small range of DSO available from a light polluted area. Then you will want to travel with a smaller scope (or equally large) to a dark site, so choose accordingly.

[michael.h.f.wilkinson]

Adding a UHC filter to your arsenal will improve views of planetary nebulae (there are quite a few) and other emission nebulae. A big dob will also show a lot of detail on planets, and Jupiter's ever variable cloud patterns and the dance of the moons can keep you happy for a long time. Besides the Messiers there are quite a few bright NGCs, many of which have made it to the Caldwell catalogue, Some really bright  NGCs didn't make it even there (NGC2903 is a case in point, beautiful galaxy in Leo). You might consider a truss-tube Dobsonian, which can be folded into a reasonably compact form, both for storage, and possible transport to dark sites

[prabal276]

any more uggetion? guy , my keyboard ha decieved me many key are not orking