Karan05

How do you find GSO barlow.. i bought for my celestron 130eq but it makes my 20mm hazy when using... Is celestron Omni better than GSO ???

On 31/12/2018 at 00:25, Alan64 said:

Hello,

I'm afraid you won't get much use out of the 20mm.  The field-of-view will be quite narrow when compared to a 20mm Plossl.  Entry-level kits do not include the best of eyepieces and accessories, so you'll want to complement the experience with a Plossl or two, or three.  The included 10mm is most certainly usable, but it's not a Plossl, either.  Plossls are the barest minimum if you're wanting performance, and they're not expensive...

https://www.365astronomy.com/GSO-Super-Plossl-Eyepieces/

I would suggest a 32mm from that listing, and to help find your way around the sky.  That will serve as your lowest power(20x), for hunting, for observing the star-studded fields of the Milky Way, the Pleiades, and the galaxy in Andromeda. 

A 20mm Plossl will give you a power of 33x, and for closer look.  You can barlow the 20mm Plossl, for a simulated 10mm, with a 2x barlow...

https://www.365astronomy.com/GSO-2x-Barlow-2-Element-Achromatic-Barlow.html

...and for a power of 65x.  A 130mm aperture is capable of reaching even higher powers, however the manufacturer equipped that model with a spherical primary-mirror, instead of the accepted and expected parabolic.  A parabolic primary-mirror is the standard for f/5 Newtonians.  Why they chose to do that is somewhat unknown.  Therefore, it will be more difficult to reach, say, 150x, whilst at the same time enjoying sharp and pleasing views.   But you can certainly attempt 150x, and where the planets and other objects come into their own; for a closer look at the craters of the Moon, and for the splitting of double-stars.  The focal-length of a 130mm f/5 is rather short, at 650mm.  Let's see what it would take to reach 150x, when the time comes...

650mm ÷ 150x = roughly a 4mm eyepiece

In that event, you would need a 12mm Plossl and a 3x barlow, and for a simulated 4mm(163x)...

https://www.rothervalleyoptics.co.uk/antares-x3-achromat-fmc-barlow-lens-125.html

Or, if you already have a 2x barlow at the time, you can get either an 8mm or 9mm eyepiece.  With the 2x barlow and the 8mm, you would have a simulated 4mm(163x); with the 9mm, a simulated 4.5mm(144x).

Those are merely examples and suggestions.

Eyepieces are fully the other half of a telescope.  The two are one and inseparable.  You can't use one without the other, unless a camera takes the place of an eyepiece, as when imaging with a telescope.  The eyepieces and other accessories do not have to be acquired all at once, and they should be chosen carefully, as the eyes from individual to individual differ.  For example, if you wear prescription-eyeglasses, and find that you need to wear them at the eyepiece, then you may need eyepieces with longer eye-relief, and in order to see the full field-of-view.  Eye-relief is noted within the specs of the listings of most eyepieces; usually, 20mm of eye-relief is preferred by eyeglass-wearers.

Eyepieces, barlows and other accessories only have to be acquired once, as long as they're not lost or broken, and they can be used with any other telescope(s) that may be acquired in future.  I have over twelve telescopes, but only one of each focal-length of eyepiece, mostly.

You can motorise the RA-axis of the kit's mount, and with an economical 9V-battery(a lithium-type during the winter) motor-drive...

https://www.firstlightoptics.com/celestron-astromaster-series/motor-drive-celestron-astromaster-geq-93514.html

Such will allow you to track an object automatically, hands-free.  It will even cause an object to stand still there in the center of an eyepiece, and for as long as you'd like.

I just bought GSO ED 3x Barlow but it makes 20mm quite hazy when i see jupiter or saturn... Do u think theres a problem with Barlow.. or something else... ... 

8 hours ago, POANDY said:

I have recently bought a used Meade computerised telescope (Meade AR6 LXD55 6" f/8 Refractor ) and have the same issue.

I am using the "diagonal" thingy and the 26mm eye piece that came with the scope.

Jupiter fills the eyepiece, but it just looks like a perfectly round white dot.  I am fairly sure it's Jupiter as the computer moves the telescope into roughly (another separate thing I need to figure out) the right position in the sky.

I can focus the scope on trees and distant landmarks, no problem.  Nice and crisp and clear.

it's a new moon right now, so I can't try looking at it for a few days.

Thru 26mm i guess even moon cannot fill up the entire eyepiece...try adjusting the focus knob...

2 hours ago, Philip R said:

Hi @Karan05 and welcome to SGL. 

What are you viewing? - Using the 10mm e/p and a 3x Barlow is way to much magnification for your 'scope.

At the time of writing, Jupiter, Saturn & Mars are low down for northern latitudes, so getting a clear view of the planet surface/disc is not going to be easy.

Thanks @Philip R pleasure being here

Im viewing Jupiter and Saturn which is at gr8 position for me Living in India...

10mm ep with 3x barlow pulls up 195x mag which i thought is still lower than company claimed 307x max useful magnification... Correct me if im wrong plz..

1 hour ago, lenscap said:

Hi Karan,

The Celestron 20mm erecting eyepiece contains a set of prisms which rotate the view to allow terrestrial observing. This produces a very narrow apparent field of view (only about 30 degrees) and a rather dim image. Replacing it with an inexpensive generic Plossl will provide a much wider apparent field (about 52 degrees) and a noticeably brighter image.

A 32 mm Plossl would also be very useful since it would provide the largest field of view available with a 1.25" eyepiece; very handy for larger DSO's.

 

Very valid point....  I was actually wondering why my field of view is narrow with 20mm... Probably gonna buy a 25mm or 32 mm.. 

That will also help me bring it closer to a more useful magnification with 3x barlow....

Does anyone suggest to buy a 6mm or 8mm plossl... Instead of using a 10mm stock..

Hi i own Celestron 130EQ which comes with 20mm erect EP and 10mm EP.... i bought a GSO ED 3x Barlow... The focus is not very sharp while using Barlow... Is it the EP at fault ???? Is it worth upgrading to Kelner or a Plossl ???? 

Hi guys !

I bought celestron 130Eq a 15 days back and being viewing Jupiter and Saturn daily... Jupiter is much sharper with 20mm stock EP than 10mm stock....

But ever since i bought 3x GSO ED barlow terrestrial views are very sharp but none of astro views are sharp... .. are the stock EP worth replacing with Plossl ones... Or current windy weather playing spoil sport ????? TIA