Author Topic: Barlow and/or small eyepieces for Celestron Astromaster 130Eq  (Read 1046 times)

Jon Beckner

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Barlow and/or small eyepieces for Celestron Astromaster 130Eq
« on: December 23, 2017, 11:45:20 PM »
Hey I introduced myself but it's yet to gain much traction.  I was wondering about a Barlow Lense and perhaps 1 eyepiece around the 4-6 mm area.  There is way to many Barlow's to pick from.  Is 1 greater than another?  I have only take out my scope 3 times now.  Yesterday I brought it to a party and set it up on the deck.  Terrible idea as every step caused the image to shake.  I did get a couple of good moon viewpoints and when I moved to look for Jupiter the angle was really hard to get so I packed it up.
Celestron Astromaster 130Eq
Filters: Moon, Red, & Blue
Eyepieces: 20mm, 15mm, 10mm, & 9mm
Finder: StarPointer Finders Scope (useless?)



Jimmy Harbaugh

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Re: Barlow and/or small eyepieces for Celestron Astromaster 130Eq
« Reply #1 on: December 29, 2017, 05:02:55 PM »
Hello Mojo! If you posted your intro on the Intro thread, many will of course read it, but few will comment on any specific questions you may have asked in that thread, and instead direct you to post here in the Beginners forum. You will get more traction here.

To your question about eyepieces... yes, somewhere between 4-6mm would be a good next choice I think. I suggest the Astro-Tech 5mm Paradigm as this will give you a 1mm exit pupil. Technically, I think you could go down to even a 4mm, but you will, I think, be bumping up against your scopes limitations, seeing conditions are rarely good enough to go much more. With a good Barlow, you will double your eyepiece collection and give you the ability to experiment with magnifications until you find the most pleasant view. GSO barlows can be had at Agena-Astro for a modest sum.

If your scope is the one I think it is, a good red dot finder and maybe a 25mm eyepiece is probably all you need to find a lot of stuff. Consider a good atlas as well. S&T Pocket Atlas is a good one to begin with.

Hope this helps!

Clear skies!

CB

Coco Moten

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Re: Barlow and/or small eyepieces for Celestron Astromaster 130Eq
« Reply #2 on: December 30, 2017, 09:12:48 AM »
Welcome to CN. The "introduction" thread that you posted to is just there to say "hello". Normally, actual questions are asked in the main forum area.

Barlow lens? Sure, buy one. They are flexible accessories. Probably a 2x would be the best all-around bet. Most Barlow lenses within a price range will be similar in performance. Generally, regular length Barlow lenses will perform slightly better than "shorty" Barlow lenses at the lower end of the market.

Smaller eyepiece? Well, a rough rule of thumb is that if you double your telescope's diameter (in mm) then you'll get a rough maximum magnification for your instrument. Very high quality instruments may be able to exceed that, but typically, due to atmospheric turbulence, it's not a bad rule. Many less expensive instruments won't make that level, or at least, satisfaction at that magnification is user dependent. So, sure, theoretically, you could buy smaller eyepieces. Maybe something in the 6mm range. As eyepieces get shorter, so typically, does the comfort of using them. That's another advantage to the Barlow - you keep the comfort of the longer eyepiece.

Maybe you could buy yourself a Barlow and try out higher magnifications with the existing eyepieces and see where the image falls apart. You could then pick out shorter eyepieces at an appropriate length.

The finder on the telescope is really just meant to help you align the GoTo system. It is very simple, but should work OK for the intended purpose..

BTW: I changed your thread title so that it actually told people what you were asking about.

Good luck.

heelmiliso

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Re: Barlow and/or small eyepieces for Celestron Astromaster 130Eq
« Reply #3 on: December 30, 2017, 04:12:58 PM »
Hi.

What do you all think of the Orion High-Power 1.25" 2x 4-Element Barlow lens? And does anyone here use a Barlow lens with a 20mm, 24mm, 30/32mm eyepiece?

riaherrvodo

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Re: Barlow and/or small eyepieces for Celestron Astromaster 130Eq
« Reply #4 on: January 04, 2018, 09:56:43 AM »
Thanks I saw that and it makes way more sense.I'm really looking forward to Tuesday. As of right now they are forecasting a 7 for sky viewing. I'm going to have to suck it up and lose some work sleep I believe. I'm not very sure how many 7's I'll get being so close to Chicago. Wish that I had the Barlow in time.

Richard Washington

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Re: Barlow and/or small eyepieces for Celestron Astromaster 130Eq
« Reply #5 on: January 04, 2018, 02:25:48 PM »
Quote
Hey I introduced myself, but it has yet to gain much traction. I was wondering about a Barlow Lense and perhaps 1 more eyepiece around the 4-6 mm area. There's way to many Barlow's to choose from. Is 1 better than another? I've only take out my scope 3 times now. Yesterday I brought it to a party and set it up on the deck. Terrible idea as every step caused the image to shake. I did get a couple of good moon views and when I went to Search for Jupiter the angle was really hard to get so I packed it up.
Celestron Astromaster 130Eq
Filters: Moon, Red, & Blue
Eyepieces: 20mm, 15mm, 10mm, & 9mm
Finder: StarPointer Finders Scope (useless?)

Welcome.  The intro thread is for introductions so people are not likely to respond to questions there. This is the right way to ask for help.

Want to confirm this is your telescope.
http://www.celestron...130eq-telescope

As to barlows and eyepieces.  You need to state a budget. How much do you have to spend. An eyepiece can be $30 or it can be $300. Same for a barlow.

However based on the telescope you have I presume you want to stay to the lower end of the price range.

You have a 650 mm scope with a 130 mm aperture. So max mag you would want to shoot for is about 260X, twice your aperture in mm.

Today you have 20 mm ( 33X) 15 (43X ) 10 (65X) and 9 (72X)   So you have the low power range covered.

A 2X barlow would give you 66, 86, 130 and 144X - too much overlap in my opinion and not high enough mag.

A 3X barlow would give you 99, 129, 190 and 226X - no overlap and it gets you close to your max mag target.

While you might want to add eyepieces because you want to upgrade, if you are trying to expand your magnifications on a budget then I would recommend a 3X barlow.  Based on the 4 eyepieces you have you would get 8 magnifications with no overlaps and your range would be from 33X to 226X. I consider that a very good range for that scope.

I read pretty good reviews of the Antares 3X - $50
http://agenaastro.co...-lens-ub3s.html

If you are willing to take a chance on a low priced barlow, I have this one.
http://www.ebay.com/...T8AAOSwr~lYq4AK

I could recommend all kinds of eyepieces and such but it sounds like you are working on a tight budget so I would add the 3X barlow and nothing else at this time.  Note that Plossls, once you get below 10 mm FL have a pretty tight eye relief and can be uncomfortable to use. So if you go below 10 mm you will want something with at least 10 mm eye relief. But I don't think you need it right now.

flasattecof

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Re: Barlow and/or small eyepieces for Celestron Astromaster 130Eq
« Reply #6 on: January 08, 2018, 02:47:41 AM »
The Televue 3x Barlow is supposed to be one of the best. May not be much cheaper than your scope though. I agree if you get a 3x Barlow you don't need to get another eyepiece. Or you can get a 6mm eyepiece and a 2x Barlow.

Scott

Brandon Belknap

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Re: Barlow and/or small eyepieces for Celestron Astromaster 130Eq
« Reply #7 on: January 11, 2018, 09:46:16 AM »
Ed's advise is very good. A great 3x Barlow is the Orion TriMag. You could probably pick one up used for under $50.

Another good Barlow choice is the GSO shorty. This is a 2x barlow, with the added benefit of turning it into a 1.5x barlow by screwing off the lens, and attaching it directly to the filter threads on your eyepiece, giving you 1.5x magnification.
http://agenaastro.co...arlow-lens.html

But with your eyepieces and scope, the TriMag makes more sense. Check the eyepiece forum for additional recommendations.

laycacdownsell

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Re: Barlow and/or small eyepieces for Celestron Astromaster 130Eq
« Reply #8 on: January 11, 2018, 10:15:57 AM »
Given how shaky the mount is, high magnification viewing will be a challenge.

Given how bad the mirror was in my 130mm astromaster, I doubt the scope will be capable of giving quality high magnification views anyway. Mushy was the best it could do.

ceusesugua

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Re: Barlow and/or small eyepieces for Celestron Astromaster 130Eq
« Reply #9 on: January 12, 2018, 02:10:56 AM »
Quote
Quote
Hey I introduced myself, but it has yet to gain much traction. I was wondering about a Barlow Lense and perhaps 1 more eyepiece around the 4-6 mm area. There's way to many Barlow's to choose from. Is 1 better than another? I've only take out my scope 3 times now. Yesterday I brought it to a party and set it up on the deck. Terrible idea as every step caused the image to shake. I did get a couple of good moon views and when I went to Search for Jupiter the angle was really hard to get so I packed it up.
Celestron Astromaster 130Eq
Filters: Moon, Red, & Blue
Eyepieces: 20mm, 15mm, 10mm, & 9mm
Finder: StarPointer Finders Scope (useless?)
Welcome.   The intro thread is for introductions so people are not likely to respond to questions there.  This is the right way to ask for help.
Want to confirm this is your telescope.http://www.celestron...130eq-telescope
As to barlows and eyepieces.   You need to state a budget.  How much do you have to spend.  An eyepiece can be $30 or it can be $300.  Same for a barlow.
However based on the telescope you have I presume you want to stay to the lower end of the price range.
You have a 650 mm scope with a 130 mm aperture.  So max mag you would want to shoot for is about 260X, twice your aperture in mm.
Today you have 20 mm ( 33X) 15 (43X )  10 (65X) and 9 (72X)     So you have the low power range covered.
A 2X barlow would give you 66, 86, 130 and 144X  - too much overlap in my opinion and not high enough mag.
A 3X barlow would give you 99, 129, 190 and 226X - no overlap and it gets you close to your max mag target.
While you might want to add eyepieces because you want to upgrade, if you are trying to expand your magnifications on a budget then I would recommend a 3X barlow.    Based on the 4 eyepieces you have you would get 8 magnifications with no overlaps and your range would be from 33X to 226X.  I consider that a very good range for that scope.
I read pretty good reviews of the Antares 3X - $50http://agenaastro.co...-lens-ub3s.html
If you are willing to take a chance on a low priced barlow, I have this one. http://www.ebay.com/...T8AAOSwr~lYq4AK
I could recommend all kinds of eyepieces and such but it sounds like you are working on a tight budget so I would add the 3X barlow and nothing else at this time.   Note that Plossls, once you get below 10 mm FL have a pretty tight eye relief and can be uncomfortable to use.  So if you go below 10 mm you will want something with at least 10 mm eye relief.  But I don't think you need it right now.
Yes this is my scope and no I'm not on a tight budget lol. I've just wanted a scope my whole life but never took the time to research & buy one (it was an xmas present). Now that I have one I want to push it to it's limits and learn as much as I possibly can. That way if I choose to start buying 300 dollar eyepieces and a better scope they aren't sitting and collecting dust on a shelf. Thanks I'll buy the 3X's barlow. Perhaps, I can order same day on Amazon and have it here for tomorrow. *Fingers Crossed*
In theory it's like playing a guitar. My first one wasn't the worst, but only a step or two up. Then once I could jam a bit the more expensive ones were much more rewarding

micfullprovlo

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Re: Barlow and/or small eyepieces for Celestron Astromaster 130Eq
« Reply #10 on: January 12, 2018, 07:54:25 AM »
Once you get the barlow, enjoy learning your scope and the skies. There is plenty of time to spend money.This is all for future consideration

Low power wide view
Flexible midrange
High quality fill in where you feel the need to add or replace

I have three scopes listed below and my primary eyepieces are also listed.

Low Power Wide View - I have a low power wide view eyepiece for each of my scopes matched to the scope. At the low power end you might consider adding a 32 mm Plossl for 20X and 2.6 degree FOV. That is about as wide a view as you can get on that scope.  A great step up from your finder scope and great for star hopping. Some nights I drop in my low power and just scan the sky enjoying the patterns and the wonder of it all.
http://agenaastro.co...60_degrees.html
Zoom - My most used eyepiece is my Celestron 8-24 zoom. $60  One eyepiece covers a wide range of magnifications. in your scope it would provide 27X to 81 X without taking it out of the eyepiece holder.  Drop it in the 3X barlow and you get 81X to 245X.  Two devices and every magnification from 27 to 245X.  Not bad.  This is what I use in my ETX 80 most of the time.  I my Orion XT8i I use it with a 2X barlow for 50 to 300X.

If you are more of a premium product guy, and it sounds like you are, then the Baader Hyperion Mark IV is the zoom you want. Almost 5X the price but reputed to be better optics and wider FOV. Not earth shattering better but it costs a lot to gain improvements and some say this is the only eyepiece they use, having retired the others. About 20% wider FOV than the Celestron.  I just added a used Baader Hyperion 8-24 so it is not the current model.

Zoom Eyepieces
http://agenaastro.co...-eyepieces.html
Filling in with fixed FL mid to high power eyepieces.

For the midrange and high mag fixed FL let me make recommendations for the future. Use the eyepieces you have but as you feel the desire to either add one or replace one with something better I would highly recommend the Explore Scientific 68 degree AFOV and 82 degree AFOV lines. Wonderful eyepieces and about half the price of the high end stuff.http://agenaastro.co...scientific.html

I use my zoom more than any other eyepiece. Then I have been filling in at the high mag end with ES 82 8.8 and 6.7 and I have a Meade 4.5 HD60.  However, if I was buying today I would get the ES 82 4.7 rather than the Meade.Nothing you need today.  This is all for consideration for the future.

litgeschsappa

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Re: Barlow and/or small eyepieces for Celestron Astromaster 130Eq
« Reply #11 on: January 13, 2018, 10:48:54 PM »
I've used a 3x with great success with my 6" f/5. Yours is an 5" f/5, and therefore quite similar.

250x is at about the very highest limit of a 5" aperture, but only if the optics are well-figured and if the atmosphere will cooperate. There are in fact several factors and variables that conspire against us in the pursuit of the higher powers; collimation included.

If you look down into optical-tube, does the main mirror at the bottom have a center-spot, like this?
If so, then you can collimate the telescope to where you can get the best images at the higher and highest powers.

Realistically, you should be able to reach 150x, on most nights I would think. A 5" f/5 has a focal-length of 650mm...

650mm ÷ 150x = either a 4.3mm eyepiece, or a 12mm eyepiece combined with a 3x barlow for a simulated 4mm(163x).

The higher powers also require a more critical, precise, alignment of the mirrors and focusser within and of the telescope, and for best image quality when viewing an object.

At 150x, at least, you'll be able to get very good views of Jupiter and Saturn, along with deep-sky objects as well, like globular clusters.

This is an image I snapped of the globular cluster M13 with the 6" f/5...
I simply held a small camera up to the eyepiece and snapped the shot, on the fly; no short or long exposure as in imaging. Such is called afocal photography, and is much easier and quicker. I only take the shots to illustrate what may be seen during a live view through an eyepiece.


Jorge Herbert

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Re: Barlow and/or small eyepieces for Celestron Astromaster 130Eq
« Reply #12 on: January 20, 2018, 03:00:17 PM »
Quote
I've used a 3x with great success with my 6" f/5. Yours is an 5" f/5, and therefore quite similar.

250x is at about the very highest limit of a 5" aperture, but only if the optics are well-figured and if the atmosphere will cooperate. There are in fact several factors and variables that conspire against us in the pursuit of the higher powers; collimation included.

If you look down into optical-tube, does the main mirror at the bottom have a center-spot, like this?

primary center-spot.jpg

If so, then you can collimate the telescope to where you can get the best images at the higher and highest powers.

Realistically, you should be able to reach 150x, on most nights I would think. A 5" f/5 has a focal-length of 650mm...

650mm ÷ 150x = either a 4.3mm eyepiece, or a 12mm eyepiece combined with a 3x barlow for a simulated 4mm(163x).

The higher powers also require a more critical, precise, alignment of the mirrors and focusser within and of the telescope, and for best image quality when viewing an object.

At 150x, at least, you'll be able to get very good views of Jupiter and Saturn, along with deep-sky objects as well, like globular clusters.

This is an image I snapped of the globular cluster M13 with the 6" f/5...

M13 - 6 f5.jpg

I simply held a small camera up to the eyepiece and snapped the shot, on the fly; no short or long exposure as in imaging. Such is called afocal photography, and is much easier and quicker. I only take the shots to illustrate what may be seen during a live view through an eyepiece.

Hi, Alan.

Thanks for the picture.

In your previous post, you said that you held the camera up to the eyepiece and snapped the shot of M13. What ocular were you using at that time? Your Parks 25mm Kellner?

As for your 6" f/5 Newtonian reflector, are you fully satisfied with the diameter of the secondary mirror?

revekosque

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Re: Barlow and/or small eyepieces for Celestron Astromaster 130Eq
« Reply #13 on: January 20, 2018, 11:05:08 PM »
Quote
Once you get the barlow, enjoy learning your scope and the skies. There is plenty of time to spend money.This is all for future consideration

Low power wide view
Flexible midrange
High quality fill in where you feel the need to add or replace

I have three scopes listed below and my primary eyepieces are also listed.

Low Power Wide View - I have a low power wide view eyepiece for each of my scopes matched to the scope. At the low power end you might consider adding a 32 mm Plossl for 20X and 2.6 degree FOV. That is about as wide a view as you can get on that scope.  A great step up from your finder scope and great for star hopping. Some nights I drop in my low power and just scan the sky enjoying the patterns and the wonder of it all.
http://agenaastro.co...60_degrees.html
Zoom - My most used eyepiece is my Celestron 8-24 zoom. $60  One eyepiece covers a wide range of magnifications. in your scope it would provide 27X to 81 X without taking it out of the eyepiece holder.  Drop it in the 3X barlow and you get 81X to 245X.  Two devices and every magnification from 27 to 245X.  Not bad.  This is what I use in my ETX 80 most of the time.  I my Orion XT8i I use it with a 2X barlow for 50 to 300X.

If you are more of a premium product guy, and it sounds like you are, then the Baader Hyperion Mark IV is the zoom you want. Almost 5X the price but reputed to be better optics and wider FOV. Not earth shattering better but it costs a lot to gain improvements and some say this is the only eyepiece they use, having retired the others. About 20% wider FOV than the Celestron.  I just added a used Baader Hyperion 8-24 so it is not the current model.

Zoom Eyepieces
http://agenaastro.co...-eyepieces.html
Filling in with fixed FL mid to high power eyepieces.

For the midrange and high mag fixed FL let me make recommendations for the future. Use the eyepieces you have but as you feel the desire to either add one or replace one with something better I would highly recommend the Explore Scientific 68 degree AFOV and 82 degree AFOV lines. Wonderful eyepieces and about half the price of the high end stuff.http://agenaastro.co...scientific.html

I use my zoom more than any other eyepiece. Then I have been filling in at the high mag end with ES 82 8.8 and 6.7 and I have a Meade 4.5 HD60.  However, if I was buying today I would get the ES 82 4.7 rather than the Meade.Nothing you need today.  This is all for consideration for the future.

Hi, Ed.

It seems that you don't use your finderscopes much anymore. Did you telescopes come with a Red Dot finder or were they a replacement?

Richard Ross

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Re: Barlow and/or small eyepieces for Celestron Astromaster 130Eq
« Reply #14 on: January 23, 2018, 04:46:08 AM »
rogeriomagellan

Not sure how you drew the conclusion that I don't use finder scopes. I use the finders on all my scopes.

ETX 80 has red dot
ETX 125 has a 6X30 RACI
XT8i came with a 9X50 and I added a red dot on a dual finder shoe.

Perhaps this comment confused you about how I use my scopes.

Low Power Wide View - I have a low power wide view eyepiece for each of my scopes matched to the scope. At the low power end you might consider adding a 32 mm Plossl for 20X and 2.6 degree FOV. That is about as wide a view as you can get on that scope. A great step up from your finder scope and great for star hopping. Some nights I drop in my low power and just scan the sky enjoying the patterns and the wonder of it all.<a href="">http://agenaastro.co...60_degrees.html[/url]

What I mean is that you are looking at something naked eye - Red dot finder. This is a great next step from the finder. Or if you are using a 9X50, this is a great next step from the finder.If I am using computer assist then the finder is used during alignment.

If I am using the scopes manually the finders are used like those on any manual scope. But I can't always see the stars I need to see naked eye in the red dot finders. My skies are pretty badly light polluted.  Naked eye the best I can see in the best part of the sky is about mag 3.5. In other parts it is worse. Some parts of my sky are completely blank to the naked eye so using a red dot is not an option. I don't even turn the scope West except for the moon and Planets.

Even with the 9X50 on the XT8i the view is limited by aperture and magnification. I can see dimmer stars and more detail in a 2" 38 mm 70 degree in the XT8i at 31X then I can see at 9X in a 50 mm finder scope. So I can see more guide stars or can recognize patterns more easily with the low power lens.

Same is true with the 6X30 on the ETX 125. Limited aperture and limited mag can sometimes make it difficult to see the guide stars or the dimmer patterns I am looking for.

I use my scopes manually about 50% of the time so those finders are critical to the experience.

And, I like the low power wide view of these long FL eyepieces.  That may come from my start with binoculars. I still often have my 10X50s with me when I am observing. I will start a session with them and will often finish a session with them.

Hope that clarifies.