Telescope Buying Help

[pulsar91]

Hey, Im looking for a telescope for planetary and deep sky viewing which is approximately 8-12 inches. what I want to know is that once I buy a telescope on a Dobsonian mount can I switch it later to an equitorial mount (for photography etc)?

And also let me know which Dobsonian reflector is the best and is cheap. Zhumell Z10, Orion XT8, SkyWatcher, Meade LightBridge

these are the ones I've researched on, if there are any other please let me know. Im open to suggestions.

Also can I attach the t adapter to a dobsonian?

Thnks

[Carbon Brush]

Are you in the UK or elsewhere?

I would avoid a 'department store' buy. Get a scope from a proper atronomy retailer.

Have you looked at 'Skywatcher' scopes?

Have you actually had hold and lift of any of the scopes?

There is huge difference in handling 8" and 12" scopes.

Tell us a litte more and the help will come flooding in.

[valleyman]

Yes you can mount a Dob onto a EQ mount later, you will need to buy some rings ana a dovetail and a solid mount. Nothing less than a HEQ5 goto for a 200 Dob

SKYWATCHER 200 IS THE CHOICE OF MOST DOB OWNERS AS A STARTER

[x6gas]

Hi Pulsar, and welcome to SGL.

You will find that, generally speaking, certain types of scope are better for visually observing deep sky objects, and another type is better for viewing planets.

Because planets are relatively small in the sky it is best to have a scope with a long "focal length" which is the parameter that, along with the focal length of the eyepiece that you are using, determines magnification. Planets, though, are also relatively bright as so you can get away with telescopes that have a slow "focal ratio". This is why Schmidt–Cassegrain telescopes (SCTs) are a popular choice.

However, deep sky objects require a lot of light gathering power because DSOs are so dim, so you need both a lot of aperture but also fast optics (which means a focal ratio of 5 or lower). Because many DSOs are actually really large in the sky, relatively short focal lengths are good too. So large reflectors are a popular choice here, and Dobsonians you get the most aperture for your money. These scopes are heavy and difficult to handle / transport when you get to large apertures, though, so as said above see one in the flesh before buying!

For DSO imaging, the game changes again! Most agree that the most important thing is to have a capable mount rather that the telescope. Small, light reflectors are often the scope of choice here because they are less demanding of the mount, have shortish focal lengths that are good for the large DSOs, and the small apertures can be compensated for by taking longer exposures.

To answer your question, you can mount the telescope tube of a Dobsonian on an equitorial mount by buying the appropriate tube rings and mounting bar BUT for a large tube (8" or more) you will need a pretty capable (and therefore expensive) mount for DSO imaging. Some people get fantastic results using Dobsonians for planetary imaging though - check out the planetary imaging forum on SGL to find out how they do it!

[pulsar91]

Are you in the UK or elsewhere?

I would avoid a 'department store' buy. Get a scope from a proper atronomy retailer.

Have you looked at 'Skywatcher' scopes?

Have you actually had hold and lift of any of the scopes?

There is huge difference in handling 8" and 12" scopes.

Tell us a litte more and the help will come flooding in.

First of all, Im in Pakistan so i'll have to import everything from US or UK. There are people over here at the Lahore Astronomical Society who have done so.

Yes, ive had some experience with a 4" Bousch and Lomb Newtonian Professional Series. The company doesnt make telescopes anymore and its old. It's mount is all broken up and is missing some things which makes it very difficult for me to operate it. Plus Im in city area and a at clear night I can easily locate a couple of constellations. I've havnt done any research of SkyWatcher, I thought Meade and Celestron were better especially in the optics? Let me know if Im wrong, I'll redo my research.

i Pulsar, and welcome to SGL.

You will find that, generally speaking, certain types of scope are better for visually observing deep sky objects, and another type is better for viewing planets.

Because planets are relatively small in the sky it is best to have a scope with a long "focal length" which is the parameter that, along with the focal length of the eyepiece that you are using, determines magnification. Planets, though, are also relatively bright as so you can get away with telescopes that have a slow "focal ratio". This is why Schmidt–Cassegrain telescopes (SCTs) are a popular choice.

Thats really awesome advice! Would it be possible to connect a DSLR on a Dobsonian mount through the T adpater? My best bet yet (I think) is that I can buy a 10" or 12" Dobsonian Relfector and then later mount it on EQ5. I dont actually want to do hardcore astrophotography but sometimes when I really get in to the mood. Plus I've seen although Dobsonian are easy to move in the sky, their not very solid. By which I mean, if I accidently hit it, it would move the object in the sky.

and i just looked at the Sky Watcher Dobsonians here. (This is the same website guys in Paksitan get their equipment from). The Sky Watcher Dobsonian doesnt have the full outer tube on it. Wouldnt the primary mirror get moisture on it

given that Lahore, Pakistan has a humid atmosphere? And light pollution would become more of a problem with such a telescope?

[John]

Hi and welcome to the forum.

On the optics, Meade are made by GSO in Taiwan who also make the Zhumell scopes and Skywatcher / Celestron are both made by the Chinese company Synta, which owns both brands now. The optical performance of all these is pretty much the same.

Do lots of research and ask lots of questions before you make a decision - where you are beased I guess you need to get it right first time really

[faulksy]

as said realy a sct will cover all your needs as they are considerd a all rounder and portable, but you will need a good mount for astro pics

[JamesM]

Just a quick note regarding your original three choices. The first two being of the solid tube variety can be mounted equatorially as they both are made of a single tube and so can facilitate mounting rings being attached. The Meade is a truss dobsonian and therefore there is not a suitable position to mount the rings. You can have a look at

his video to see how it might be possible to adapt the Meade to an equatorial mount but the mount itself needs to be mounted very low to the ground.

James