Anyone know anything about telescopes?

[Andre]

I'm looking at buying a good starter kit for exploring the night sky. It should be quite portable for trips to the Richtersveld and other places I visit, as well as being able to show the moons of Jupiter, rings of Saturn etc. in other words, a reasonable magnification. I don't necessarily need automatic tracking, but would be a nice to have. Have had a look at some of the sets at Cape Union Mart.... Can anyone offer advice here?

[core fly]

Check out www.telescopeshop.co.za
i am sure these are the right guys to ask as you will get the best possible info and offer the best starter kit.I have also thought about looking into this but i first want to buy myself a decent mountain bike

[FlyFanatic]

Hi Andre,

Jup, you get 2 types, reflector & refractor type telescopes.

Reflector type where you have a large mirror at the end of the tube reflecting the light back towards the eye piece & focusing it there.

Refractor type where you have all the light passing through a series of lenses with the eye piece at the end.

Here is a nice website which explains the differences: http://scopeviews.co.uk/Beginners%20...%20Article.htm

Started building a 6inch reflector a few years back, grinding & polishing my own mirror. Takes a hell of a lot of time, never finished it..

Nevertheless I have a cheapie (cape union mart type) refractor, has served me well, can see Jupitors moons, Saturns rings & the Moon craters very nicely on a clear evening. So if I where you, go with one of the Cape Union mart ones, you will have a lot of fun & then you can build on that!

Enjoy!

[Andre]

Ya thanks, this is good. I am told that aperture is more important than magnification, and with this in mind, a reflector type is probably better for an entry level setup. When it comes to higher end units, I understand the refractor type to be better. Also hearing that an aperture of less than 6 inches is not going to be any good for any viewing out side the solar system and into deep space. A basic deep space unit that can view the nebula and the galaxies, is going to have an aperture starting at 8 inches, and going to start at about R12K...hectic...
I have been looking at the Cape Union ones, and seem to be the right option for a cheapie, which is probably the way to go for now, although comparative sets are cheaper from the specialist people. For the basic Celesteron units Cape Union looks to be about 25% more expensive.

[FlyFanatic]

Ja for sure, the high end refractor units have the best optical quality as well, however you are going to fork out quite a bit for them.

Celestron is a big name in this business, even their entry level units should be good. Buy the entry level 6inch reflector and you will not have any regrets.

Then start building your own, forget about grinding the mirror, however you can buy the mirrors from overseas. The rest of the telescope is limited only by your imagination!

If you really fancy building one, give me a shout, I have A LOT of info on this.

[Andre]

Cool will do, thanks a lot for the help/

Ja for sure, the high end refractor units have the best optical quality as well, however you are going to fork out quite a bit for them.

Celestron is a big name in this business, even their entry level units should be good. Buy the entry level 6inch reflector and you will not have any regrets.

Then start building your own, forget about grinding the mirror, however you can buy the mirrors from overseas. The rest of the telescope is limited only by your imagination!

If you really fancy building one, give me a shout, I have A LOT of info on this.

[redhumpy]

as well as being able to show the moons of Jupiter, rings of Saturn etc. in other words, a reasonable magnification.

I take one down for the Uni to Matjiesfontein every year for our Space Geodesy workshop. You can see the "rings" just fine but the image is still just a white ball with a white ring. It's a basic telescope - telescope cost - about 120K.

Rather buy good binoculars for 7K and spend the rest on a good galaxy coffee table book. You will use the Swarovski's or Lynx more and it will give you more pleasure.

[Korrie]

I take one down for the Uni to Matjiesfontein every year for our Space Geodesy workshop. You can see the "rings" just fine but the image is still just a white ball with a white ring. It's a basic telescope - telescope cost - about 120K.

Rather buy good binoculars for 7K and spend the rest on a good galaxy coffee table book. You will use the Swarovski's or Lynx more and it will give you more pleasure.

I have heard your recommendation a couple of times.

[redhumpy]

This is a pic of our small telescope set up at Matjiesfontein. Wanted to treat the staff.This telescope actually has GPS and you can just gooi the coords and it will find say Jupiter for you.
STILL, at best you will see the craters on the moon nicely and the rest is still just a white dot with a ring around it.
matjies 1.jpg

Having an "intro" or "basic" telescope is not as WOW as many think it is. Buy the binoculars...

The one in the pic which I don't think is fantastic you can buy here:
http://store.meade.com/telescopes/lx...ld-tripod.html

[gus]

Hello all, a very overdue visit to the forums. I have a few telescopes and can maybe give you some advice here.

Binoculars and Spotting scopes.

The biggest question you need to ask is what you are looking to get out of the equipment. If you are simply looking to take something portable with you that can give you a great view of the local planets/clusters/moons then I would agree with looking into a good pair of binoculars or a spotting scope. They are very versatile, quick to setup and can be used for both terrestrial viewing and sky viewing. I would recommend trying to get one with a standard eyepiece as you can then get a moon filter for it, yes the moon is very bright when viewed directly at full moon and you can damage your eyes otherwise. The biggest complaint though that I have heard from people who get spotting scopes is that objects look dim, this is purely a result of the amount of light coming through a small aperture when viewed under high magnification. It cannot be avoided but is not a show stopper. You will be able to see the moons of Jupiter and make out some details on the planet, rings of Saturn will look good and there is plenty of interesting objects that will keep you busy with a good pair of binoculars or spotting scope. However deep sky objects are beyond the ability of such things.

Good discussion around using scopes. http://www.cloudynights.com/ubbthrea...Number/3990427


Telescope Concepts
Magnification is purely a product of the eyepiece placed into the telescope. What you want is to get the most light into the telescope as possible hence larger aperture, as you increase magnification you reduce the amount of light available.

Magnification = [Telescope Focal Length]/[Eyepiece Focal Length]

Some cool calculators on such things.
http://www.astro.shoregalaxy.com/index_010.htm

Eyepieces
All telescope eyepieces come in two sizes, 1.25" and 2".
If you buy a Telescope that is 2" compatible it can be reduced to handle 1.25" eyepieces but obviously the reverse is not possible.
Attaching DSLR cameras directly to telescopes requires a 2" eyepiece holder.

Telescopes

Below are the three main types of telescopes found today with some pros and cons of each, I personally own a 10" and 8" reflector so may be a bit biased to those. All three of these have models ranges from simple $100 buys to $1000 fully automated systems. There are also varying sub-types of these mentioned below with more specific applications.

A. Reflector (Big mirror at back type, open tube)
http://upload.wikimedia.org/wikipedi..._telescope.svg

Pros :
Price for the mirror size.
Easy to understand and operate.
Fantastic range of operation, planets, moons, nebula, galaxies all within the ability of a 8"+ scope.
Accessories aplenty from filters to attaching DSLR's directly.
Dobsonian reflectors are great starting scopes.

Cons :
Gotta keep the tube nice and clean. And don't get me started on cleaning the primary mirror.
Bulky, the tube length is a direct result of the focal point and results in long tubes for the mirror size. (10" tube mirror has a focal point of 1.2m so makes for a very long tube)
More susceptible to warping if not looked after.
Cannot be used for terrestrial viewing. (Well it sort-of can but objects can not be focused at close distance)


B. Refractor (Lens at front and lens at back)
http://upload.wikimedia.org/wikipedi...x-Kepschem.png

Pros :
Easy to maintain and setup.
Sealed unit so cleaning inside is not required.
Can be used for terrestrial viewing.
Good beginner scope.

Cons :
Price per inch is alot higher than reflectors. Lenses cost more than mirrors.
Great for viewing close sky objects but lack the light absorption to really be able to view DSO's unless you can afford a large aperture.


C. Schmidt Cassegrain (Corrective lens in front, mirror at back , 2nd mirror in front)
http://upload.wikimedia.org/wikipedi...-Telescope.svg

Pros :
The Rolls Royce of the home telescope.
Amazing optical quality.
All the benefit of a large mirror reflector without the tube length. The corrective lens creates a artificial focal point shorter than the tube length.
Sealed unit reduces maintenance.
Accessories galore.
Eyepiece at the back is easier to use than the eyepiece on the side as in reflectors.

Cons :
Most expensive of the options.
Heavy unit.
Stay clear of cheap designs as they are known to have left people disappointed.


Conclusion.
Cheap telescopes are well cheap for a reason. Yes some people will be satisfied with the optics and may get many years of fun out of them but I have found tons of these in yard sales and on bid or buy as people have buyers remorse. I'm not saying spend R10000 on your 1st scope but rather look at the well know brands that have proven optics.

Brands : Meade, Celestron, Orion(not to bad), Takahashi, Tasco(Bushnell, some good models but lots of junk) however in saying those they have all been know to make cheap junk at stages so do your research. Forums ftw.

Little did people know that we have our very own Telescope and Astronomy Expo every year. You have just missed this years but can be a great way to see and talk to people that really know what they are doing. http://www.scopex.co.za/

I have never regretted the telescopes that I bought and have had years of wonders as a result. Here are some snaps of the one scope and some objects I have photographed. Sorry for the quality as I don't have the originals with me.

http://i.imgur.com/G4NQAU6.jpg
http://i.imgur.com/2Rm9LL3.jpg
http://i.imgur.com/p9ohKJp.jpg
http://i.imgur.com/IfKJ3OB.jpg
http://i.imgur.com/9Y6pPFv.jpg
http://i.imgur.com/GJ1GtC0.jpg
http://i.imgur.com/ouzqjqN.jpg
http://i.imgur.com/nTklQwX.jpg
http://i.imgur.com/edR4iCS.jpg (Yes you can just put take a snap with a boxcam through the eyepiece)
http://i.imgur.com/E5GPGRy.jpg
http://i.imgur.com/0CFHt05.jpg (Comet Lunin)

The single biggest piece of advise I can give comes from the website below. The best telescope is the one that gets used.

http://www.deepastronomy.com/best-telescope.html

If you have any more specific questions just ask.

Regards,
Gus