suggestions for scope

[keeplookingup]

hi guys. I am about to buy a scope and have been viewing the sky for years.

I have a 4.5" reflector but its back in the states and i live in China now. will settle down here.

I do not enjoy the reflector because it isn't comfortable when using it.

I think i like refractors style more. I will of course go to stores and see them to check out the feel.

im seeking suggestions on scopes that are not too big but will allow me to.

1. view planets

2. view some deep sky objects

3, begin my astro photograpy

my price range is about 700 to 1000 us dollars.

something that is portable(short tube) and can be used for a very long time.

which company is best?

thanks in advance.

[lw24]

hi guys. I am about to buy a scope and have been viewing the sky for years.

I have a 4.5" reflector but its back in the states and i live in China now. will settle down here.

I do not enjoy the reflector because it isn't comfortable when using it.

I think i like refractors style more. I will of course go to stores and see them to check out the feel.

im seeking suggestions on scopes that are not too big but will allow me to.

1. view planets

2. view some deep sky objects

3, begin my astro photograpy

my price range is about 700 to 1000 us dollars.

something that is portable(short tube) and can be used for a very long time.

which company is best?

thanks in advance.

Hi,

You've asked a few questions, which I'll try to answer, but it would help if you could answer the following questions:

Firstly, you mention you want to begin astro photography. Is this deep sky astro photography (very expensive) or planetary/moon photography (less expensive)?

You say you want to view planets and deep sky objects, but what would be your preference? Long tube refractors are better on planets, and short tube refractors are better for deep sky objects.

Anything from Skywatcher, Celestron, Tal, Vixen and Williams Optics is fine.

Clear Skies

[ronin]

Not sure of US prices but for astrophotography many use decent refractors, which means something in the 80mm ED class. 80mm triplet is better but as they are short focal length you would need a flattener/reducer to get rid of curvature. Flattener/reducers aren't cheap.

For starters I would suggest an 80mm ED refractor something in the range of f/7.5. Bigger F number but flatter field.

Next you need a solid EQ mount with a set of dual motors at least. The budget doesn't really allow for a goto mount of any size, but eventually goto allows for a guide camera to be fitted. Future upgrade?

80mm will not show you visually to wonders of the deepest depths of the universe. However a dark site is probably better then a larger aperture in poor skies. 80mm refractor is a good transportable size also.

Locate the astronomica site, think they have some offers at present.

[keeplookingup]

i would hope to be able to do both if possible?

i mean hope not to have to use two scopes for photographing different objects.

im so green to this stuff that i dont know anything yet

yes future upgrade is something i need to consider as well

for example

I would just like to get started with viewing stuff and then later get the camera going(don't understand CCD) and so on.

what i always thought(probably wrong) is that a small scope wouldn't reveal as much. but then again i have read that good small refractors do very well.

thanks guys

[brantuk]

How about one of these: First Light Optics - William Optics GT-81 Triplet Refractor

It's about the right budget, very nice for when you do get imaging, and ought to be fair for observing as well. I use a Meg 72 and it's fine for both (although there are better refractors for dual use but much more expensive)

[JamesF]

Lots of generalisations here, but it should give you an idea of why finding one scope to do everything may well be infeasible...

For visual planetary work you'd probably want plenty of magnification which typically means a long focal length scope. That generally puts you into the realms of SCTs, Maks and "slow" (long tube) refractors.

For visual DSOs magnification isn't *such* an issue and in fact high magnification may mean you end up "looking through" some DSOs because you can't get the entire object in the field of view. If you want to avoid reflectors then for wider fields of view you're really looking at "fast" (short tube) refractors. Unless such a refractor has been specifically designed to avoid the problem by using corrective lenses and/or different types of glass, fast refractors can give odd colour effects (colour aberration) that's particularly noticeable on the moon and planets, though some people don't have a problem with it.

For planetary imaging you need to get lots of data fast -- you can't hang around because the planets are spinning so you have to get everything you need before rotation causes the image to blur. That requirement seems to lead people towards using larger aperture SCTs and Maks to capture as much light as possible with as much magnification as possible.

For DSO imaging you're often after a wide field (short focal length) scope and you need a lot of time to capture the data to create your image because there's so little light coming from such a distant object, so you need a mount that will track the object very well over long periods of time (typically hours), but aperture isn't so important because you can always just give it more time. Adequate mounts are not cheap, and you may well still want additional kit for guiding.

You also have to remember that your eye isn't a camera and doesn't work the same way, so what's good for visual won't necessarily be good for imaging.

If you're dead set on a refractor then I think brantuk's suggestion is a fair compromise. You should get ok views of the planets without colour aberration (though at relatively low magnification), you should be able to see a fair range of DSOs (though many of them will be little more than faint fuzzy blobs) and it should well work for DSO imaging later on. There's always a risk that you might end up wishing you'd bought something slightly different and planned to add a second scope for planetary work later on, but such is the nature of compromises...

James

[ollypenrice]

For visual observing you need aperture. The focal length of the telescope really doesn't matter because you control the magnification via the eyepiece. (I'm disagreeing with James, above, here. What you need for planetary observing is a long effective focal length, ie scope and EP combined.)

For planetary imaging you need aperture and long telescope focal length.

For deep sky imaging you need whatever focal length will frame your target nicely, a fast focal ratio (F8 absolute minimum) and a flat field.

The scope that can do all this does not exist at any price, it is as simple as that.

So Brantuck's suggestion of the new WO GT81 is one way to compromise. Two members have posted DS images with this (it does need a flattener) and they look brilliant. You would get great widefield views, great DS images, but less performance on the planets, considerably less for imaging them.

To go for the other side of the compromise this is an excellent scope;

First Light Optics - Skywatcher Evostar 100ED DS-Pro Outfit

It will do better on the planets visually and in imaging, better on some DSO's visually and less well on others, but even with reducer it will be slow going as a DS imaging tool.

Olly

[JamesF]

For visual observing you need aperture. The focal length of the telescope really doesn't matter because you control the magnification via the eyepiece. (I'm disagreeing with James, above, here. What you need for planetary observing is a long effective focal length, ie scope and EP combined.)

I knew if I attempted to simplify things too much I'd get corrected somewhere Olly is of course correct.

I think it's probably fair to say that it would not be correct to get the impression that you could just get any short focal length refractor and use eyepieces/barlows/etc. to increase the focal length to get good magnification for planetary viewing though. There are other factors that come into play.

James

[ronin]

Considering that you are in China look around for suppliers of the Long Perng range or the United Optics ranges.

WO (Taiwan) is another option as well.

I would suspect that (a) FLO will not ship to China, ( could well be import problems.

[keeplookingup]

well i have much to learn.

i don't know which is better now for my needs. a reflector or refractor. i keep reading different stories and confused now haha

[Capricorn]

Well since you say:

I do not enjoy the reflector because it isn't comfortable when using it.

I think i like refractors style more. I will of course go to stores and see them to check out the feel.

im seeking suggestions on scopes that are not too big but will allow me to.

1. view planets

2. view some deep sky objects

3, begin my astro photograpy

That would sort of bias you towards refractors. They match the numbered criteria you state pretty accurately.

If size is a problem I would have said an ED or triplet refractor of 90mm possibly 100mm. Not too big but would match what you ask for. Bigger ones would possibly be too much for the astrophotography side, and simply carrying around.

Depends on the light pollution, but if dark then a small scope will show an awful lot.

I have the WO Megrez 90 and that fits what you have say very well, problem is that I understand they are being discontinued.

[keeplookingup]

I need a book on telescopes so i can understand the vocabularies you guys are using haha

cool, more to learn

i have to consider all things

what i want to see

do i want to image or visual

portable

budget

i will take into consideration all the great advice you guys have given me and read up on everything more so I can at least know what you mean on focal lengths etc etc.

i just got word from my sister that she maybe will give me the 4.5" reflector she no longer uses. IF i can lug it back to China with me from the states.

if so, then i have time to use this scope and get more familiar with things and research more before i drop my hard earned RMB on some scope.

thanks guy

i love this forum