Newbie Eye Piece Question

[JohnKA]

Hi

I have a quick question about extra eye pieces and Barlows.

I have just bought a Celestron Astromaster 90AZ, I know its an entry level bit of kit, but was wondering if its worth buying other eyepieces or a Barlow ?

The telescope came with 2 eye pieces, 10mm and a 20mm. Are these 'kit' eye pieces any good or would I have better results using others ? or with a Barlow ?

TIA

[iamjulian]

Standard advice seems to be, use them for a while. Get used to whether you prefer the wider view of the 20mm or the reach of the 10mm, then upgrade your eyepieces gradually based on this knowledge. Unless you are loaded, in which case buy lots of really expensive eyepeices right away. You could also go to a local astronomy group and ask to have a look through other people's scopes, to get an idea of how your own eyepieces stack up. Hope that helps.

[Andrew*]

Hello - welcome to SGL!

I understand that your 90AZ has a focal length of 1000mm (F/11), and the included eyepieces offer 50x and 100x. This is a good start, to be honest, but you would do well to get something a bit more wide field - a 32mm plossl, for example. This would offer 31x. That's good for finding objects and viewing larger objects.

Also, your telescope can theoretically handle 180x magnification - useful for planetary viewing. A 6mm would get close, at 167x. The problem with a 6mm plossl is the eye relief gets very small. A 6mm ortho would be better - these sometimes come up quite cheap second hand. Another alternative would be to get an 11mm or 12mm plossl and a 2x barlow. This would work quite well, because you could also use the barlow on your 32mm eyepiece to get, in effect, a 16mm eyepiece.

With eyepieces for these two focal lengths, you would make a valuable extention to your spread of magnifications and therefore objects you can view.

Andrew

[Ant]

The eyepeices that come witht he scope will be OK. But they are also entry level and there are much better out there even for a small(ish) outlay.

I found this link, it has some spec on your scope. AstroMaster 90AZ Telescope (item #21063) / Celestron.com - Telescope | Computerized Telescopes | Microscopes | Binoculars | SkyScout

This is a 90mm (3.5") scope and it's highest magnification is going to be about the x175 mark.

You eyepeices give x50 and x100. So I think that for the most part a barlow would be pointless as a x2 barlow would exceed the x175 for the 10mm and increase the x50 to x100 (which you already have).

When you are ready to invest some more money an eyepeice in the 6 or 7mm area will be a nice addition - and remember that the eyepeices that you buy can be used for your next scope as well..

HTH

Ant

[SteveP]

Hi John

Welcome to SGL

As you say, your scope is an entry level model and I predict that if you stick with this infuriating hobby, you will outgrow the scope in the not too distant future. That is an almost universal truism! Keep that in mind when you are buying any additional kit. At this stage, I'd get used to your scope and the EP's you already have. I suspect they won't be of the highest quality but will work well at this stage whilst you're learning about the scope and the heavens. Don't get sucked into buying stuff before you can make use of them. If however you do decide you want something a little more powerful, eg in the 5-6mm range or something which provides a wider field of view in say the 30-35mm range then you might consider buying 2nd hand

Good luck

Steve

[JohnKA]

Hi

I managed to pick up a Celestron Omni 32 mm Plossl but am after a 6-7mm. Have seen the Skywatcher SP eye pieces from the link above, are these a fair quality bit of kit or is it better to spend a few £'s more ?

Thanks

Also why is it when you buy a telescope, near enough every night has been cloudy ?

[Andrew*]

If you feel like spending more, I can guarantee you won't be disappointed with this eyepiece: TMB 6mm Planetary Premium Eyepiece | Astronomica

Lots of eye relief, better optics than the SW, larger FOV. Can't be beaten on price IMHO.

Andrew