Help me choose the best refracting telescope

[nae8ean]

What do you think about this one is this good for viewing Jupiter & Saturn and what is the Maximum & Minimum of magnification for this? 

anyone here has a Skymap picture so i could easily locate the planet or star   and does the planet change their position every day on the constellation of the star?

 

 

KSON KTA80072U Refracting Telescope

Model: KTA80072U

Objective Lens: 72mm aperture, 800mm focal length f/11.1, air-spaced Achromatic lens with broadband multi-coating.

Tube: Machined Aluminum tube, with Pearlised White finished

Mounting System: Alt-Az Yoke mount with declination micro-adjustment.

Focuser: 1.25" Metal focuser with Helical Rack & Pinion

Erecting Prism: Built-in 20mm 45° high definition Erecting Prism, dual functions for astronomical and terrestrial observing.

Eyepieces: 1.25" F20mm and F6mm

Barlow: 3x Barlow

Finder: Red Dot Finder with two-position brightness control.

Tripod: Quick setup KT4 metal tripod , with 630mm-1080mm height, accessory tray specially designed to enhance stability of the tripod.

Packaging Size: 99x41x18.5cm

[Schorhr]

Hello Nae8ean,

I work with kids and I have seen quite a few beginner telescopes.

These plastic fork mounts with "fine ajustment" threaded rod STINK.

The refractor is OK but not great.

On (german) ebay classifieds and ebay you see about four or five each day selling for 5-15€ (4-13gbp)- for a reason.

Why does it have to be a refractor? There ARE great refractors, no doubt, but they have a higher price.

A reflector telescope may have a few downsides but you get a much larger aperture for a lower price.

If I see it correctly, that telescope sells for 4000PHP = 65€ = 54gbp.

If I see it right you have a 50mm refractor already. This thing won't be much of an upgrade, really. Save your money :-)

A 80/900 refractor would be the smallest "Upgrade", though a 5" (130mm) newtonian would show you so much more and is even a bit cheaper usualy. As Dobsonian mount it is very rigid, too.

A 60-70mm telescope will show you

http://www.ringohr.de/tmp6//2013-05-05_Sketch2_76_jup.bjpg.jpg

http://www.ringohr.de/tmp6//2013-05-04_Saturn-h76p_3.jpg

A 100-130mm telescope will show you

http://www.ringohr.de/tmp6/jup20110831.jpg

http://www.ringohr.de/tmp6/saturn_small_130p_260x.jpg

And starts to show a few deep sky objects (that the ring nebula is actually a ring, starts showing outer star of star clusters, shapes of galaxies...)

As far as deepsky goes aperture is the main factor.

http://translate.google.com/translate?hl=&sl=de&tl=en&u=http%3A%2F%2Fwww.binoviewer.at%2Fbeobachtungspraxis%2Fteleskopvergleich_deepsky.htm

The maximum magnification of the refractor you posted is ~140x, but depending on the optics chromatic aberration will show and lower the contrast. The mount will make tracking and finding things difficult.

With a 100mm telescope its about 200, with a 130mm telescope it's theoretically 260... (rule of thumb: 2 x aperture diameter in mm)

As for learning the sky, check out Stellarium http://stellarium.org.

The visible constellations change from season to season, as do the position of the planets. Everything is moving in the solar system, so it's allways different ;-)

During sun set Venus is visible as brightest star. In binoculars or telescope you can see phases, it looks like a little moon shape.

Right now Jupiter is up starting at the evening, near gemini, and rises together with Orion nebula. Both are fun to view in even the smallest telescope.

Mars is up later, and in the morning Saturn.

These planets can be observed in amateur telescopes well and are so bright they are easily spotted with the naked eye.

[nae8ean]

thanks 

[Pete Presland]

another vote for stellarium!

have you thought about contacting these people http://www.philastrosociety.org/  they may know some local telescope suppliers.

i could recommend plenty of scopes but i would not be able to help you with whether they are available to you in the Philippines.

[nae8ean]

Thank bunnygod i already download stellarium but not compatible on my video card btw i got application on iOS and android that could help me find easily the planet or star or any comet or what ever it is. I downloaded sky map , star chart & comet watch there is more application that could help me identify what it is i don't want to buy on other country it could not arrived on my place like my other item i bought on ebay and my budget is not exceed to 5,000 pesos ($121.95) but here in philippines  i saw newtonian 4.5" reflecting telescope with cheap price and not exceed to my budget but i'm afraid to buy because i don't know how to maintenance the collision and dust and it so big to take it on some place i want compatible to carry outside my home :s 

[Schorhr]

Hello nae8ean,

for how much did you see the 4.5" reflector telscope, what mount does it come with?

4.5" is a decent starter size! :-) It's available for 74-150€ here depending on the mount.

Usually the mounts are to weak though.

You can how ever build a rockerbox for around €5.

http://ringohr.de/tmp6/76dob1b_1.jpg

Not pretty but a rockerbox does not shake as much as the cheap tripods and mount heads, especially for planetary observation at high magnification that's important.

COLLIMATION

About newton collimation: Don't worry. It's easy once you've done it with a tutorial. And at the aperture ratio at f/7.89 (if it's a 114mm with 900mm focal length) collimation is usualy not critical unless the mirror is way off ;-)

SIZE

A 72/800 is not small either,

for size comparison see http://translate.google.com/translate?sl=de&tl=en&js=n&prev=_t&hl=de&ie=UTF-8&u=http%3A%2F%2Ftaunus-astronomie.blogspot.com%2Fp%2Ferfahrungsberichte-teleskop-neu.html

or

refractor 70/900 on tripod http://www.zudensternen.de/Teleskop%20%20Saturn%2070%20900%20EQ-2.html

&

114/900 on dobsonian-rockerbox http://www.star-shine.ch/astro/teleskope/teleskope.html (bottom pictures)

Weight and size really doesn't differ much, though the rockerbox is set up quicker.

DUST...

...is an issue with all telescopes. But that's what dust covers & lids are for. Dust sits on lenses just as much as on lenses.

Dust covers just little actual surface area. Even if it looks dirty, it's usually best to NOT clean optics.

And IF, DON'T use a cleaning cloth, glass gleaner or air spray. And don't blow it off, saliva can cause all kinds of problems.

A small bellows/blower from a camera shop will work, or contact-less gleaning with just distilled water. But read one of the guides here on the forum when it's really unavoidable.

I can understand that you want to buy it locally :-)

Aren't there any telescope shops?

[nae8ean]

Thanks for the advice on the link u gave using refractor 70/900 they can see the saturn like on their sample pic not like the other said its dim and so small . On my country there is a telescope shop but they only sell kson and all i know kson is made in china and i don't know if their optic really high quality multi coated like they said on their webpage.