Author Topic: Need advice on getting first eyepieces.  (Read 488 times)

Ligon Payton

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Need advice on getting first eyepieces.
« on: December 29, 2017, 01:00:57 AM »
Hello! I've had a Nexstar 130 SLT for a couple of months. I feel pretty comfortable with the basics of using my scope. After catching Jupiter recently, that really made me want to upgrade! I'm still pretty new and just plan on doing casual observing. Although I've done quite a bit of reading, I still feel somewhat overwhelmed with all the options. I live in Texas, just outside of Dallas. But I have a good spot away from light pollution. Currently I just have the eyepieces that came with the scope, 9mm and 25mm. My first purchase would likely be a 2x barlow and an eyepiece. What would be a good focal length to start with? Budget-wise I'm ready to spend around $100 on the barlow and $100 on the eyepiece. I'm looking at a Televue 2x barlow for $120.



notaslasof

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Re: Need advice on getting first eyepieces.
« Reply #1 on: December 29, 2017, 10:12:01 AM »
The televue barlow is well made, you'll like it.  With your 9, it'll give you 4.5 , so you should go for a big field, which would mean something longer than 25mm, like a 32mm, which with your barlow would hit between your 9 and 25 and give you a 16, you'll find that if you get a shorter focal length ep, like a 7 or 6, you'll rarely use it, and almost never with the barlow. You could go with a 12 or so, but with the 25 you're pretty much around there anyway with the barlow. A 30 or 32mm ep with the barlow would give you 4.5 (the 9mm barlowed), 9, 12.5 (the 25mm barlowed) , 15/16 (the 30/32 barlowed), 25, and 32, which would be a really good working range. I've got some pretty short focal length ep's, and they just don't get the use because of seeing.

Bryce Roberts

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Re: Need advice on getting first eyepieces.
« Reply #2 on: December 31, 2017, 06:49:29 AM »
The 130SLT can use 2" eyepieces, thus I'd recommend a 2" Barlow. Get the Astro-Tech or GSO 2", it'll be fine.

I'd recommend a 32mm Agena SWA and a 5mm Astro-Tech Paradigm. The Paradigm Barlowed is the highest power usable, and the SWA will give the widest field you can get. The SWA Barlowed will work for medium power.

Paul Kasilowski

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Re: Need advice on getting first eyepieces.
« Reply #3 on: January 04, 2018, 06:32:33 PM »
at 32mm F/L, it is fairly easy to construct a decent performing EP, so your options are wide (pun intended). The 130SLT comes with some pretty basic EPs, so eventually you will want to upgrade. Consider buying into a decent series, as down the road, IF you go further with the hoppy, you will appreciate them all the more. If you only do a modest increment now, with the intent of getter ever better EPs, then I would suggest you shop here on the classifieds, as many do the same thing.I hesitate to recommend any specifics, as your budget, plan, and physical requirements for back focus can vary widely. I like the Explore Scientific, Baader, and Meade 4000 and 5000 series. Televue are excellent, but i think beyond your current position (although the Plossls are a reasonable starting point.If you want to get into modest AP, the Baader Hyperions are easily adapted for eyepiece projection photography. Also, Baader has an excellent 8-24 clickstop zoom, that is probably better across all the positions than your current EPs. I have one, that I rely on for grab and go, with my smaller scopes, vs carrying all the EPs with me.Also, carefully consider one decent LPR filter, and a Moon Filter.

tmasnilypho

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Re: Need advice on getting first eyepieces.
« Reply #4 on: January 08, 2018, 08:29:43 AM »
What would be the advantage of going with 2" barlows/eyepieces over 1.25"?
How are the celestron luminos eyepieces? They're pretty well priced for a large FOV.

Woody Boelkens

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Re: Need advice on getting first eyepieces.
« Reply #5 on: January 09, 2018, 01:58:41 PM »
Quote
What would be the advantage of going with 2" barlows/eyepieces over 1.25"?
How are the celestron luminos eyepieces? They're pretty well priced for a large FOV.

2" allows for a wider field of view.

The 2" Luminos eyepieces have issues.

David Williams

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Re: Need advice on getting first eyepieces.
« Reply #6 on: January 11, 2018, 06:04:45 AM »
Whatever you try, buy used from well-rated sellers here on CN and flip the ones you don't like.

David Pee

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Re: Need advice on getting first eyepieces.
« Reply #7 on: January 11, 2018, 01:11:01 PM »
Quote
Whatever you try, buy used from well-rated sellers here on CN and flip the ones you don't like.

I agree!  I'm a newbie too but i bought a 8-24mm zoom eyepiece like the one celestron offers but it's by olivon. I got a good deal on it for 60 through the cn classifieds and it's a great eyepiece. 
Also i think a barlow to start will really expand your range.  I was maxed out on what i wanted to spend so i went with a really cheap vite 2x barlow from ebay for $16. I dont have much to compare it with but I'm pretty happy with the results. It's just something to consider if you don't want to spend too much upfront.

puzzweetscareg

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Re: Need advice on getting first eyepieces.
« Reply #8 on: January 11, 2018, 03:42:21 PM »
Quote
Quote
Whatever you try, buy used from well-rated sellers here on CN and flip the ones you don't like.

I agree! I'm a newbie too but i bought a 8-24mm zoom eyepiece like the one celestron offers but it's by olivon. I got a good deal on it for 60 through the cn classifieds and it's a great eyepiece.

Zhumell offers it for $40....

gimartutin

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Re: Need advice on getting first eyepieces.
« Reply #9 on: January 12, 2018, 01:24:57 AM »
Quote
The 130SLT can use 2" eyepieces, thus I'd recommend a 2" Barlow. Get the Astro-Tech or GSO 2", it'll be fine.


Good 2" eyepieces aren't cheap. I've never seen a need or use for a 2" Barlow with my gear. A 1.25" Barlow is handy though in short ratio designs like this.

The first question I have is whether or not the original poster is satisfied with the 9mm that came with the scopeand plans to build around it long term? If the answer is "yes" then there is less need on that end when combined with a 2x Barlow. If the answer is "no" then selecting a newmid power eyepiece that can be Barlowed to around 150 - 200x becomes more important. The problem here is that simple designs in the ~7mm range are very short eye relief so Plossl's drop out and other affordable recommendations are needed.

A 32mm Plossl will provide about 2.4 deg of field with the scope. It is going to be difficult to go much wider inexpensively and get decent edge of fieldcorrection in this small f/5. So with the budget in mind I would probably limit to a 32 Plossl on the low end for the time being.

dogswargersdurch

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Re: Need advice on getting first eyepieces.
« Reply #10 on: January 12, 2018, 02:16:26 AM »
Quote
Hello! I've had a Nexstar 130 SLT for a couple of months. I feel pretty comfortable with the basics of using my scope. After catching Jupiter recently, that really made me want to upgrade! I'm still pretty new and just plan on doing casual observing. Although I've done quite a bit of reading, I still feel somewhat overwhelmed with all the options. I live in Texas, just outside of Dallas. But I have a good spot away from light pollution. Currently I just have the eyepieces that came with the scope, 9mm and 25mm. My first purchase would likely be a 2x barlow and an eyepiece. What would be a good focal length to start with? Budget-wise I'm ready to spend around $100 on the barlow and $100 on the eyepiece. I'm looking at a Televue 2x barlow for $120.

I presume this is your scope:
http://www.celestron...rized-telescope

Aperture (mm) 130 mm (5.12 in)
Focal Length 650 mm (26 in)
Focal Ratio 5
Focal Length of Eyepiece 1 (mm) 25 mm (0.98 in)
Magnification of Eyepiece 1 26 x
Focal Length of Eyepiece 2 (mm) 9 mm (0.35 in)
Magnification of Eyepiece 2 72 x

I have a large selection of eyepieces but my most used eyepiece is the Celestron 8-24 zoom.  In your scope that would give you 27X through 81X.
http://agenaastro.co...m-eyepiece.html
Match that with a 3X barlow and you would have all magnifications from 27X through 243X.  I think the meade or the Antares would be good choices but you can't go wrong with the Tele Vue
http://agenaastro.co...lt/?q=3X barlow

For as little as $100 you have every magnification between 27 and 243X.  Over time you can fill in with single focal length eyepieces. You can see the ones I have. But some nights all I use is the zoom and a barlow in my 80 mm refractor, my 127 mm Mak or my 8" Dobsonian.

trodnenwisen

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Re: Need advice on getting first eyepieces.
« Reply #11 on: January 12, 2018, 08:06:09 AM »
Heya,

I find that it's easy to go overboard with eyepieces and end up only using one or two. I like medium power overall best. But I enjoy sweeping with really low power first. And when I'm wanting to really look at something, I don't care to fill the FOV with it, because the high power isn't always going to work out depending on how the seeing is and how well your mount can handle the focal length & high power magnification steady. For example, I used a 5mm eyepiece the other day on my 1,000mm refractor on a manual Alt-Az mount. It took a while for that thing to settle after I focused it, and at that magnification, the FOV being so tight, by the time it settled, it was time to move the scope (manual slow mo control) to get the object back in view. But then I had to wait for it to settle again. Realized real quick, there are limits and your mount has a lot to do with it with eyepieces and magnifications. The moment I went back down to a 15mm eyepiece and dropped magnification, the scope was settling much faster in the same situation, at least to perception, and I was able to view more often and faster. Point being, the higher the magnification goes, the more stress will be placed on the mount keeping the scope steady.

Instead of having a bunch of eyepieces, I'd do:

32mm (1.25" or 2" doesn't matter) with wide AFOV (68 degree or more is great) for a wide sweeper.
24~8mm 1.25" zoom (these are just super handy and convenient and inexpensive and replace having a handful of plossls).
5mm or 6mm high power, looking at a dual ED or an Ortho, for planets and binaries (when seeing is good).
2x barlow (get a cheap one, you may not use it as often as you think with eyepieces unless you're trying to split a double or look at a planet and seeing is really good).

Seeing is a big limiter at higher power.
Your mount is a big limiter at higher power.

Very best,

Jeremy Kelley

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Re: Need advice on getting first eyepieces.
« Reply #12 on: January 12, 2018, 05:37:23 PM »
Keep in mind the OP is thinking about ~$100 on Barlow and $100 on an eyepiece to start. That is not a lot of room to test combinations. It boils down to more like two eyepieces or one eyepiece and one good 2x Barlow as the OP is considering. It is possible that the right combination could yield a 3rd component (e.g. another eyepiece.) There is a largedifference between what I would try with the gear to maximize its potential, and what the OP has and the budget foraugmenting it. ~$200 is kind of tight. (On the other hand, decades ago I started out trying to fit in OEM eyepieces and a Barlow witha budget and limited additional eyepieces...and I eventually replaced all but the quality Barlow. There is the short term at work vs. what the OP might use long term. Unfortunately, this is highly subjective and until you try some higher end/wider field eyepieces, you don't know what you prefer.)

I would be inclined to use an inexpensive 32 Plossl for the low end, and a good 2x Barlow combined with a decent eye relief 7mm for the high end (60 deg apparent field perhaps?) using the Barlow to max it out when seeing allowed. But the combination of all threeis likely somewhat over the OP's budget unless used and/or accepting some lowerend combinations.

pmethinxlamna

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Re: Need advice on getting first eyepieces.
« Reply #13 on: January 12, 2018, 06:14:52 PM »
First off 2" eyepieces are heavy, might max out the drive system on your scope, I went to a brick and mortar store and had the chance to see what someone had recommended I purchase for max field of view, the eyepiece was huge and very heavy. Don't do it!
Your best bet is as aeajr suggested, get an 8 to 24 zoom, Celestron, Meade, ect, under a hundred, and X3 barlow or ES focal extender, brings you in at less than your max budget and it's an excellent starting point.
Max field of view isn't the only thing to consider, it's nice but in larger scopes that can collect the light.

Edit: Also the variable contrasting filter is a great first filter, take some time and learn how to use these tools.

Todd Topcic

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Re: Need advice on getting first eyepieces.
« Reply #14 on: January 13, 2018, 03:43:39 AM »
"My first purchase would likely be a 2x barlow..."

This Antares 2x barlow is a great buy for the price...

http://agenaastro.co...ead-ub2stl.html

...unless you're simply wanting to spend twice the amount. I have the Antares 2x, without the twist-lock feature; the model immediately preceding. I have the Antares 3x, too, and both are excellent...
You don't need a 2" barlow. The only eyepieces that are usually barlowed are of the 1.25" format, and for the higher and highest of magnifications.

I'd recommend said 2x barlow, and this eyepiece, with both powers, 72x and 144x, to cover the higher powers...

http://agenaastro.co...epiece-9mm.html

Or, skip a barlow entirely and go with these planetary eyepieces...

http://agenaastro.co...netary/bst.html

Those eyepieces have barlowing elements built in to them.

Those combinations and variations only scratch at the surface, for there are just so many choices so as to boggle the mind.

I'd also check your telescope for collimation. Collimation, or alignment of the two mirrors with the focusser, is critical for the higher powers, and for best image quality...

http://agenaastro.co...t-eyepiece.html

Collimation instructions...

http://www.schlatter...y/collimate.htm
http://www.forumskyl...Collimation.pdf

You can alternately choose a laser collimator, but any laser unit chosen must be checked for alignment before using it to collimate the telescope itself...

https://www.youtube....h?v=bE09_X43UUQ

Always heed the warnings on the label...

http://www.astromart...99/784790-2.jpg

I, personally, do not recommend laser collimators for those just starting out, nor for households with children present.