Advice needed please.

SteM

Hi folks,

My girlfriend has a pair or highpowered binoculars that she loves using on clear nights. She's been talking about getting a telescope recently and I noticed that QVC are doing one at the moment. Would some of you folks who know a bit about these things be able to look at the spec & price below and tell me what you think please?

Thanks,
Stephen.

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Celestron Powerseeker 675x 900mm x 114mm Reflector Telescope

Today's Special Value £129.60
UK Postage & Packaging £7.45

Explore the mysteries of the night sky with this Newtonian reflector telescope. With magnification of up to 675x and an optimum magnification of 225x, it allows clear observation of the moon, planets and stars. An equatorial mount compensates for the Earth's rotation, enabling you to track stars and planets. The telescope has a 114mm (4.5") aperture, a 900mm focal length and a 5mm by 24mm finderscope. It comes with three eyepieces (4mm, 12mm, 20mm), a 3x Barlow lens and a CD-ROM with a database of 10,000 celestial objects to help you locate stars.

amen

anything that promise 675x magniciation is probally a waste of
time.

The size of the lenses is more important than magnification
Bigger lenese mores light better image

The description below reads like a Tasco especially the lense descriptions

a good place to check out is

http://www.telescope.com/jump.jsp?itemID=0&itemType=HOME_PAGE

if you need more info post back

SteM

Yeah, from reading other threads here everyone mentions that the bigger the lens the better.

Thanks for the advice, I really don't have a clue what I'm looking for here

albertw

Well its about £20 cheaper than most UK shops stock it for.

The 4.5" mirror is a little small, it will gather about 2.5 times more light than 10x50 binoculars. (someone will correct my calculation if Im wrong!). So if you use an eyepiece that gives more than 25X magnification you will get a less bright image than with the binoculars. So it may not gather enough light to make use of high magnification. Presonally I'd advise going to at least a 6" mirror, that will gather nearly twice as much light as this 4.5", and will allow you to use higher magnification.

A 6" scope will probably cost at least twice as much as this one though. So consider a dobsonian mount. These are cheaper, and more portable, and since you wont be doing photography or adding motors to it then its the better choice. (ok you will be able to do webcam astronomy).

The accessories are a bit hard to judge. However my 2X barlow cost over 200 stg, so the quality of their 3x probably wont be brilliant, and is very unlikley to be of use with this scope, perhaps only for lunar observing.

Just read `amen`s reply. Yea the 675X is rubbish, thats with the 4mm and 3X barlow, a combination that I cant imagine working in any scope really. the 225X is the optimum (50 times the diameter of the mirror in inches), and that only holds under ideal seeing conditions. It does read tasco like, and I see david hinds is advertising tasco again. Will someone in Celestron learn something about brand names stop diluting their good reputation please?!

Personally, I'd advise saving up for a 6" dobsonian. Despite this, I know someone who has a helios reflector of similar spec to this and finds it great. It will afterall pick out the cloud bands on jupiter, rings on saturn and polar cap onmars that you wont get with binoculars.

Have a look through telescope FAQ's online and you should get an idea of what to look for, and what to avoid.

hth,
~Al
--
Irish Light Pollution Awareness Campaign
www.irishastronomy.org/ilpac

SteM

Guys, thanks very much for the advice. Looks like I'm going to have to put in a bit of serious studying before I make a purchase!

Capt'n Midnight

114mm - this SOUNDS like the size of the mirror - it's smaller than a CDROM. - Beware Tasco (and others) make the body of the scope wider than the mirrors - if you wern't cynical you'd say standisation keeps costs down.

There used to be a rule of thumb about how much magnification you could get per inch (or cm) of mirror or lens size - it's to do with how much the light gets diluted before it gets into your eye I think.

halenger

I'm sure it's been said already but basically the larger the apperture the more light it lets in. More light = good thing.

Tasco etc are all machine made lenses. Some scopes along the lines of Tasco (possibly them) have been known to use Plastic in their eyepieces! This of course is terrible.

Scopes like any of the big names Celestron, Meade, etc etc etc, all have hand finished mirrors/lenses and this is exactly what you need for astronomy.