AstroMaster LT 60AZ - Eyepieces for Solar System Bodies

[Naten]

I'm not sure if this is in the right forum, sorry if it's not.

I have an AstroMaster LT 60AZ, which I've already used to observe a couple of the brighter deep-sky objects (from light polluted suburb skies!). It's a good scope, even though it's only $110 on Celestron's site, and for a 60mm refractor it's given me a lot of good views. The best are probably of the planets and the Moon. Using just the 20mm and 10mm eyepieces it comes with, it's served me well. They give 35x and 70x magnification, respectively.

According to Celestron's specs of the scope, it has a highest useful magnification of 142x. 

Would it be practical to buy an eyepiece with a higher magnification? If so, any eyepiece that you can recommend to me? Thanks.

[Ben the Ignorant]

Hi.

I have a very good, optimized 80mm/600mm achromat that can't be used over 150x for planets (but accepts 255x for doubles because they don't have the fine detail and subtle contrast of planets), so I doubt your 60mm could really use 142x, 120x seems more reasonable. With a 700mm focal length, you'd need a 6mm eyepiece like this one:

http://www.teleskop-express.de/shop/product_info.php/info/p149_Super-Ploessl---6mm-Brennweite---1-25----FMC-Verguetung.html

I had a 60mm/800mm for a while, that I bought used just to restore it, then I gave it away. I think I used 128x (not sure) but the image didn't benefit much over 96x (if memory is correct). Chromatic aberration was very low, even when aiming at super-white mercury-vapor lamps, but a 60mm achro hits the roof at 100x or 120x. I would buy only one extra eyepiece for it, investing more would be justified only for a larger scope.

I have observed in scopes between 40mm and 400mm, and binoculars between 21mm and 80mm; personally 70mm is the smallest scope that I find satisfying, and 80mm is the smallest I would spend big on. 

[Naten]

2 minutes ago, Ben the Ignorant said:

Hi.

I have a very good, optimized 80mm/600mm achromat that can't be used over 150x for planets (but accepts 255x for doubles because they don't have the fine detail and subtle contrast of planets), so I doubt your 60mm could really use 142x, 120x seems more reasonable. With a 700mm focal length, you'd need a 6mm eyepiece like this one:

http://www.teleskop-express.de/shop/product_info.php/info/p149_Super-Ploessl---6mm-Brennweite---1-25----FMC-Verguetung.html

I had a 60mm/800mm for a while, that I bought used just to restore it, then I gave it away. I think I used 128x (not sure) but the image didn't benefit much over 96x (if memory is correct). Chromatic aberration was very low, even when aiming at super-white mercury-vapor lamps, but a 60mm achro hits the roof at 100x or 120x. I would buy only one extra eyepiece for it, investing more would be justified only for a larger scope.

I have observed in scopes between 40mm and 400mm, and binoculars between 21mm and 80mm; personally 70mm is the smallest scope that I find satisfying, and 80mm is the smallest I would spend big on. 

This may be a stupid question, but would the eyepiece be useful for other scopes? Do a lot of scopes have a 1.25" barrel diameter?

[Ben the Ignorant]

Eyepiece barrels are standardized: either 1.25" or 2". And any eyepiece from any brand works on any scope from any brand provided it's either 1.25" or 2".

All scopes have a 1.25" focuser, or a larger focuser with a 1.25" reducer. That eyepiece would work with any scope, except the obsolete and not practical 0.96" format.

[Putaendo Patrick]

You can certainly increase the magnification with another eyepiece. Generally I roughly calculate the maximum magnification of a telescope by doubling the aperture in millimeters, so x120 in your case. Even so, I would probably go a bit less - perhaps x100.

A 7mm eyepeice will give x100 while a 5mm eyepiece will give x140. There's an enormous variety to choose and a wide range of prices. A Plossl design would work well, but it does have limited eye relief, you might consider something like this: http://agenaastro.com/meade-series-4000-6-4mm-super-plossl-eyepiece.html

If you're hooked on astronomy and thinking of upgrading your telescope, then a slightly more expensive EP might be a good investment. For example: http://agenaastro.com/agena-1-25-dual-ed-eyepiece-5mm.html

Remember though that magnification of a specific EP depends on the focal length of a telescope and this may differ. To get the magnification, divide the focal length of the scope by the focal length of the eyepiece.

 

[John]

I started out with a 60mm refractor. It was of decent optical quality and I had enough good views of well known objects to get me hooked on the hobby of astronomy. I found there was no point in using a magnification of more than 120x with my scope though. Often the sharpest views of solar system targets such as Jupiter and Saturn came at around 80x-100x. I used to use 120x to split tight double stars and to observe the lunar surface when the conditions were good.

With your scope I would think that a useful additional eyepiece would be something with a 7mm focal length which would give you 100x magnification or possibly a 6mm for 116x. As long as they are 1.25" fitting eyepieces these will be useful if you move on to other scopes.

[spaceboy]

Despite having several other larger scopes to choose from at the time a celestron 60slt was probably my most used scope and one I still have today. Far better finder that the tat they throw on the astromaster so I could at least find what I was looking for. I would advise you get yourself a nice red dot finder then consider higher magnification eyepieces.