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#1 pete123

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Posted 16 October 2018 - 02:47 AM

Celestron nexstar 8 gps xlt

Hi im just starting out and need to buy some eyepieces , ive been looking at the celestron x-cel as they have a good writeup and a decent price , my question is should buy a 24mm and a 2x barlow lens or will i get better results buying a 24mm and a 12mm and carry on buying single lenses .
Thanks
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#2 Jond105

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Posted 16 October 2018 - 03:14 AM

As much as this is more of a personal preference question, you could easily buy the 24 and use the a Barlow and be happy, as opposed to buying the 24 and 12. I for the longest time was against Barlows, but as of late I've been using them in my ST80 and I generally 3x Barlow my ES14 82* in my dob for planetary observing

#3 pete123

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Posted 16 October 2018 - 03:19 AM

Thanks for the reply jon , its planets i mainly want to look at for now , and with no experience of lenses do you think i should get a 24mm for wide angle of the moon and a 2x or 3 times barlow for further out planets

#4 Jond105

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Posted 16 October 2018 - 03:36 AM

What's your focal length?

#5 sg6

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Posted 16 October 2018 - 03:37 AM

You will get both answers and in similar proportions, so likely best to make your own decision.

 

I prefer individual eyepieces, but in my early days eyepieces were not great and barlows were worse. So adding in the poor end of a coke bottle was best avoided. Things have improved, and improved a lot.

 

Also I do not want to started handling eyepieces and barlows and all the permutations involved.

 

A barlow will not double the range available to you. If you bought the X-Cel LX 7mm then a barlow creates a 3.5 and that is often too short. Lets say the 7mm and 5mm are not really suited to barlowing. If you have the 25 then drop to 12.5 and could still need something around the 18mm range. So there is in a way only a band in which a barlow may make sense.

 

I use Paradigms, similar to X-Cels, and at the end I worked out that a barlow added nothing to the simple focal lengths available and to purchase a barlow was in effect the same cost as an eyepiece purchase.

 

I prefer less glass in the system. It is easy to forget that the barlow was not designed for your scope, also the barlow and any eyepiece are not designed specifically for each other.. All 3 work reasonably well as a series but no more then reasonably.



#6 pete123

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Posted 16 October 2018 - 03:44 AM

I like that
Thanks for taking the time , i think ill buy 2 eye pieces ,maybe keep my eye out for a cheap seconhand barlow later on just to play with , so i have a nexstar 8 gps what first 2 lenses would you recomend for viewing planets , i would realy like to get a half decent view of saturn if thats possible where iam lol, and some nice viewing of the moon

#7 pete123

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Posted 16 October 2018 - 03:44 AM

I like that
Thanks for taking the time , i think ill buy 2 eye pieces ,maybe keep my eye out for a cheap seconhand barlow later on just to play with , so i have a nexstar 8 gps what first 2 lenses would you recomend for viewing planets , i would realy like to get a half decent view of saturn if thats possible where iam lol, and some nice viewing of the moon

#8 Jond105

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Posted 16 October 2018 - 03:44 AM

sg6 brought up the good point. I purchased the set of Meade HD60, same as Xcel. Their parfocal with little focus adjustment. Where as sticking a barlow in there will require a good rack in on the focuser. I purchased the Xcel 2x and 3x Barlows to use in the ST80 for reasons of tight doubles and that being a fast scope. Other than that I use it only for 1 eyepiece in my dob

#9 Jond105

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Posted 16 October 2018 - 03:45 AM

No one knows where you are



#10 pete123

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Posted 16 October 2018 - 03:46 AM

Lol iknow that but thats a light pollution joke more than anything

#11 pete123

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Posted 16 October 2018 - 03:47 AM

Im in essex in th uk

#12 Ed D

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Posted 16 October 2018 - 03:54 AM

I have a 6" Mak with similar working focal length as your 8" SCT.  For visual I rarely use my 7.5mm eyepiece, usually preferring 9mm or 12mm.  For the widest field of view at low magnification you may want to consider a 24mm 68* FOV eyepiece, if your scope visual back is 1.25", even if it's not the same line as the other eyepieces you are considering.

 

For really high mags on the moon you may still want a good quality 2x Barlow.

 

Ed D


Edited by Ed D, 16 October 2018 - 03:56 AM.

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#13 pete123

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Posted 16 October 2018 - 03:59 AM

Thanks Ed
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#14 aeajr

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Posted 16 October 2018 - 04:38 AM

You asked a simple question about using a barlow.   What follows is about setting an eyepiece strategy for your ongoing purchases.  If this is not of interest, just skip it. 

 

========================================
I am going to outline my eyepiece strategy.  After accumulating over 20 eyepieces I have focused in on this approach.   I have used this for my Orion XT8 8”/203 mm Dob, 1200 mm FL, as the example.  But the same strategy applies to my 80 mm F5 refractor and my 127 mm F15 Mak.    If your FL is different you can redo the calculations for your scope. 

 

STRATEGY SUMMARY

  • One or two low power wide view eyepieces
  • One or two midrange eyepieces
  • Two to four high power eyepieces that include a plan for the top target magnification for that scope
  • Or, Zoom plus Barlow to cover mid range and high power
  • Planning to use a barlow can save you money

Selecting an Eyepiece - Orion telescope
This is a very general discussion of eyepieces and why there are a variety of designs
https://www.youtube....h?v=m7u9Q5hV7yc

 

Useful Formula -

Highest target top magnification =  aperture in mm X 2   So, for my 8" Dob, 203 mm aperture that would be 406X under exceptional good conditions.  For my 80 mm this would be 160X. For my 127 mm this would be 254X.   This is not a limit it is just a target to establish a range of magnifications.  

 

Power or Magnification = Focal Length Scope / Focal Length eyepiece

 

True Field of view  = Apparent Field of View eyepiece (AFOV) / magnification of eyepiece (This is a simplified formula that will provide a very close approximation under most circumstances)

 

Lowest power – often a spec provided by your telescope maker. But it can be whatever you like.   I would recommend something with an exit pupil of no more than 7 mm.  Exit Pupil = Focal length of eyepiece / Focal ratio of scope. If your scope only takes 1.25” eyepieces, your lowest power widest view would be a 32 mm Plossl (50 degree AFOV) to define your lowest power.  If you have a 2” focuser you can likely go lower and wider.

 

Now divide the mag range into three parts.  Using my Orion XT8i as the example, Orion recommends lowest useful as 29X, highest useful as 300X and highest theoretical as 406X.  So I will work out the eyepiece range somewhere between 29X and 300X    For this scope, that beaks down to up to under 100X for low power.    100X to 200X for medium power.  Over 200X as high power.

 

Here is a sample range, for illustration purposes based on a 1200 mm FL.   Remember the formula is:  Power or Magnification = Focal Length Scope / Focal Length eyepiece

 

 

  31X = 38 mm

  60X = 20 mm

 

100X = 12 mm

120X = 10 mm
150X = 8 mm

171X = 7 mm

200X = 6 mm   (can be achieved with a 12 mm and 2X barlow)

 

The above magnifications work almost every night at my site, under my observing conditions.  The magnifications below work when the atmospheric conditions are very good.  See the reference section for information on “seeing”.

 

240X = 5 mm   (can be achieved with 10 mm + 2X barlow)

266X = 4.5 mm
300X = 4 mm   (can be achieved with 8 mm + 2X barlow)
Over 300X – I usually barlow one of my other eyepieces as I can rarely use this much mag

 

You don’t have to have all of these magnifications, but the more you have the better you can match to your target and conditions. Note that the mm gaps get smaller as the power goes up. 

 

Here is how I have addressed this range for my Orion XT8i.  I use many of the same eyepieces in my other two scopes. 

 

Low power

 

38 mm 2” - I have the Agena Astro SWA, same as the Orion Q70 series. I use the 38 mm 70 degree AFOV in my XT8i.  Happy with it but it does show edge distortion in my F5.9 scope.  I consider it acceptable for the price but some would not.  https://agenaastro.c.../agena_swa.html

 

20 mm 2” - I also have the Meade 20 mn 82 degree as my second 2” low power wide view that performs well for me in my F5.9 scope.
https://www.astronom...pieces_c75.aspx

 

 

 

For my Single FL 1.25” eyepieces  I have the Meade and ES 82s.   Like them very much

 

Meade 82 degree
https://www.astronom...pieces_c75.aspx

 

Explore Scientific 68 degree and 82 degree line.  I have two of the 82 degree and really like them.  Many reports compare these favorably with the premium eyepieces.
https://agenaastro.c...scientific.html

 

 

 

TIGHT BUDGET? – Get a zoom and a barlow     An 8-24 mm zoom eyepiece plus a barlow somewhere between 2X and 3X will give most people the full typical mag range of their scope $100.   For your scope, if you get the zoom I would not get a barlow unless you need to push higher than the zoom will go. 

 

 

THE ZOOM EYEPIECE INSTEAD OF SINGLE FOCAL LENGTH EYEPIECES – This is my favorite eyepiece. 

 

The zoom is single eyepiece that effectively replaces a range of eyepieces.  Works like the zoom lens on a camera.   For example an 8 mm to 24 mm zoom would overlap 4 eyepieces above and provide every magnification between them.  If I include a 2X barlow for use with the zoom it will provide every magnification from 50X to 300X without gaps, my primary planning range.

 

The zoom sounds great, but there is a trade-off.  The field of view of the zoom runs from a narrower AFOV at the 24 mm range to a wider FOV at the 8 mm range.  So, like any approach, the zoom is a compromise.  I find that compromise quite acceptable when weighed against the benefits listed below, I prefer the zoom. 

 

I use the Baader Hyperion Zoom.  8-24 mm as my only eyepiece in the midrange and I barlow it to extend it to the high range for the XT8.  But as I have a low power wide view 20 mm eyepiece I tend to use the zoom mostly in the 18 mm to 8 mm range for the midrange.  

 

Lower cost zoom – Celestron 8-24 – This was my first zoom.  Works well at the price and a good way to test your interest in zooms. $66

Higher priced Zoom – Baader Hyperion 8-24 mm – My main eyepiece in my Orion XT8i – $290
https://agenaastro.c...lanetarium.html

 

  • I never expected the zoom eyepiece to become my primary eyepiece, but it has.
  • With a zoom, the eyepiece seems to disappear as you just move in and out at will, no swapping, no thinking about eyepiece changes
  • The Celestron 8-24 zoom is good and comparable to my Plossl eyepieces
  • The Baader Hyperion is great and comparable to my Explore Scientific eyepieces
  • Watching doubles split as I rotate the barrel is wonderful
  • One filter serves over a wide range of magnifications, no screwing and unscrewing to try other eyepieces
  • Moving smoothly between small changes in magnification helps when seeing is not the best
  • I am always working at the optimum magnification for this target.
  • Sharing the view with others is easier, especially in my manual tracking Dob - I hand it over at low mag so it stays in the view longer.  They zoom back in to whatever magnification works best for them.
  • My eyepiece case has been greatly simplified
  • Kids love the zoom

When I observe, 90% of the time, in all of my scopes, I use one or two low power, then the zoom for the midrange.  Then I barlow the zoom for the high range if I need it, and that is all I use.  I have single FL eyepieces in my kit, but they are rarely used.

 

 

REFERENCE RESOURCES

 

Barlow Lens - A barlow is an intermediate optical device that goes between the eyepiece and the objective lens or primary mirror.   It effectively gives each eyepiece two magnifications, one with and one without the barlow. A 2X barlow is used in the example below.  For visual use, barlows ranging from 1.5X to 3X are common.   So, if you have 3 eyepieces properly spaced and add a barlow, you now have 6 magnifications.   You can read more about barlows at this link:  http://www.telescope...rlows/99807.uts

 

 

What is SEEING and why it can be bad.  How it will limit how high you can go.

This is not a problem with your telescope or your eyepiece.

http://www.skyandtel...ing-the-seeing/
http://www.damianpeach.com/seeing1.htm
http://www.damianpea...m/pickering.htm

 

Lower Cost Single FL eyepieces – for your Medium to high power magnifications.

AT Paradigm line 60 degree AFOV.   I don’t have these but I read so many good reports about them, especially in scopes of F5 or higher focal ratios.   The Agena Astro Dual ED are the same eyepieces under a different label.

https://www.astronom...pieces_c52.aspx

https://www.cloudyni...s/?hl=+paradigm

 

Zoom eyepiece review – Includes the Celestron zoom –

This is an older review and the tech specs may not match the current Celestron zoom, but I find the comments nicely reflect the performance of the Celestron zoom I own –

http://www.chuckhawk...m_eyepieces.htm

 

Baader Hyperion Mark IV Zoom review   - The current model  -

https://astronomycon...ox-january-2018

 

A very good discussion, by Al Nagler, about eyepieces and magnification for those who want to go a little deeper.
http://www.televue.c...page.asp?id=102

 

Eyepiece Designs -  This is the one I turn to when I am trying to understand or explain the differences between the various designs.  There are many different designs, Many are named
for their original designer, such as Huyghens, Ramsden, Kellner, Plossl, Konig, Erfle, Branden and Nagler.
http://www.chuckhawk...ece_designs.htm

 

Discussion about Paradigm eyepieces
https://www.cloudyni...s/#entry8229760
https://www.cloudyni...s/?hl=+paradigm

Meade 82 vs. ES 82

https://www.cloudyni...e-82-eyepieces/


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#15 pete123

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Posted 16 October 2018 - 05:03 AM

Thanks Aeajr
Theres a lot to look through there i will take my time with that , but thanks for taking the time to do that
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#16 Mike W.

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Posted 16 October 2018 - 07:58 AM

ajajr has complied most of the answers to questions you're going to start having, I'd suggest the you save his post for reference as the questions come up and to read as much of it as you can.

 

He uses 1200mm as his focal length for the recommended eyepiece focal length, your scope has a focal length of just over 2000mm

so for your scope 9mm focal length eyepieces are going to provide 225X and 11mm will provide 184X

Most of the time 200X is going to be about max magnification, 10mm will be perfect 99% of the time.

 

I purchased a set of the X-Cel LX's for a scope a while back, for the price they have very good optic's. $45 used is the average price on this side of the pond.


Edited by Mike W., 16 October 2018 - 08:06 AM.

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#17 epee

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Posted 16 October 2018 - 08:13 AM

I would also recommend that you look carefully at the eye relief of the various eyepieces you are considering. If you wear eyeglasses, and choose to observe with those eyeglasses on (necessary if you are astigmatic), then you will want eyepieces with at least 16mm of eye relief and 20mm is better. There are many wonderful eyepieces but, if you have to wear them as a monocle and then have an astigmatic view, you've wasted your money.


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#18 AJK 547

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Posted 16 October 2018 - 09:08 AM

Totally agree with aeajr as the zoom (Baader 8-24 MkIV) is my primary eyepiece for 90% of my viewing. I will use the TV32P as my 'finder' EP when needed, then use the Baader zoom to the quickly determine my 'seeing' conditions. If the planetary views hold up at 8mm (187X) then I'll determine if I want to use the Baader Barlow (2.25X) or separate EP's for detailed enjoyment.

I've recently done some inside daytime lens chart testing on all my EP's and found that the Baader zoom works extremely well as a 'package' with very little image degradation across the entire range.

Edited by AJK 547, 16 October 2018 - 09:13 AM.

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#19 aeajr

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Posted 16 October 2018 - 09:23 AM

pete123

 

Tips:


COUNTRY/REGION/STATE:  A good thing to do, if you have not, is to go into
your profile and enter your country and/or your city so people who are
trying to help you will know approximately where you are in the world.  Top
right of the screen you will see your screen name with a little down arrow.
Go to My Settings.  This is where you can make a number of changes.


SIGNATURE:   Also, I recommend you create a signature (my settings)
where you can list your telescope your eyepieces or whatever you wish.  My
signature is at the bottom of this post.  A signature helps people help you
because they know what you have.  We get a lot of requests from people
saying, "I am new, what eyepieces should I get?"   Now we play 20 questions
to find out what telescope they have, what eyepieces they already own, etc..


BUDGET: When asking about things to buy it is good to provide a budget.   An
eyepiece can be $30 or it can be $300.  If we don't know your budget we
don't know how to advise you.  In fact, consider rephrasing your question
to, "I have $200 to spend on eyepieces.  I have the following telescope and
eyepieces.   What would you suggest?"   Give it a try.


LINKS: If you are asking a question about a specific product I suggest you
provide a link to that product so we know exactly what you are talking
about.  For example, Orion sells the Starseeker IV 150.   Well, it turns out
there are two different telescopes that could be described by that name.
One is a 150 mm Newtonian reflector and the other is a 150 mm
Maksutov-Cassegrain.   Or someone says they just got a 4” Celestron GoTo
scope and wants to know what eyepieces to get.   Well, Celestron makes a
number of 4” GoTo scopes.   If there is no link then people will answer
based on the one they think you are asking about rather than the one you
want to know about.


If you are not in the USA, a link is even more important.   Offer a link to
a web site in your country that sells telescope equipment so we can try to
understand what things cost and what equipment is available in your country.


Part of what makes Cloudy Nights so great is that people are very happy to
help one another.  These tips just make it easier for us to help each other
or to understand what is being discussed in the thread.  I hope you find
these tips helpful.


Glad you decided to join us in the sky.   smile.gif


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#20 pete123

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Posted 16 October 2018 - 09:30 AM

Thats a very good point i will do that
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#21 aeajr

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Posted 16 October 2018 - 09:33 AM

Let me be clear.  I have nothing against using individual eyepieces to create your eyepiece magnification range. I have a full set myself.   I believe this is the way the majority of people like to work.   

 

My discussion about zoom eyepieces is to bring forward an alternative eyepiece approach that many do not know is available, an approach that works well for me. 

 

And some use zoom eyepieces in addition to single focal length eyepieces.


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#22 jallbery

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Posted 16 October 2018 - 09:35 AM

Celestron nexstar 8 gps xlt

Hi im just starting out and need to buy some eyepieces , ive been looking at the celestron x-cel as they have a good writeup and a decent price , my question is should buy a 24mm and a 2x barlow lens or will i get better results buying a 24mm and a 12mm and carry on buying single lenses .
Thanks

Barlows do some good things and some not so good things.  

 

On the plus side-- first and foremost-- Barlows allow you to get double use (or perhaps even more) out of many of your eyepieces.  In addition, Barlows cause the eyepiece they are used to see a slower focal ratio than what the eyepiece would receive without the barlow.  On a fast telescope (say F/5 or faster) a 2X (or more) barlow can considerably reduce the amount of astigmatism at the field edges.  Finally, most of the tradition eyepiece designs (Plossls, Kellners, Abbe Orthoscopics, Erfles, Koenigs, etc.) are scaled designs.  This means that as the eyepiece focal length gets shorter, the amount of eye relief is reduced proportionally.  Plossls offer an excellent price/performance ratio,. but in focal lengths less than 10mm, many people find the eye relief too short for comfortable viewing.   A 2X barlow with a 15mm plossl delivers the same field as a 7.5mm plossl, but you keep the larger eye lens and eye relief of the longer eyepiece.  In fact, the barlow will actually extend the eyerelief of the original eyepiece slightly.

 

Now for the not-so-good points.   First of all, no lens is perfect: a barlow adds additional glass which means some transmission loss and possible reduction of contrast (although in well-made Barlows the amount of image deterioration should be minimal and may very well be imperceptible).   Also, as I mentioned in discussing the pros of Barlow use, a Barlow extends eye relief slightly.  This happens because the Barlow relocates the exit pupil, and for longer focal length eyepieces, this can mean pushing the eyepiece beyond its designed capability, which can lead to vignetting and the introduction of additional aberrations.  So Barlows tend to work best with shorter focal length eyepieces.   Finally, Barlows (particularly the physically longer ones) can make for awkward eyepiece positioning.   One of the nice things about an alt-az-mounted SCT is that it provides a relatively consistent eyepiece height and a Barlow can interfere with this.

 

So what does all this mean for you?

 

You have a F/10 SCT.  It's very friendly to eyepieces.   The X-Cel eyepieces you are considering are not a scaled design-- they basically already have a barlow built in.  So the only reason to want a Barlow is to get double duty out of your eyepieces.  The 25mm X-Cel is long enough it may have vignetting issues, so I'd opt for two eyepieces.

 

If budget is a concern, I'd skip the 25mm X-Cel and get a 32mm Plossl.  It has a bit wider of a true field (even if the apparent field of view is less than that of the X-Cel) and at $40-ish USD, they are a bargain.   I don't have the X-Cels, but I have full set of the very similar HD60s.   I seldom use the 25mm, preferring either a 35mm Ultima, 32mm Plossl. or 24mm ES-68.   And while the shorter HD60s have a considerable advantage in viewing comfort over similar focal length plossls, there is no such advantage on the long end.

 

On a C8 for planetary, 12mm is about where I start.   The 12mm HD60 is very good, and I would expect the X-Cel equivalent to perform similarly (I've heard it claimed that the optical design is the same).   On good nights, you'll want something shorter for planets on a C8.  If you get a barlow like the GSO shorty that has a barlow element that unscrews and can be attached directly to the eyepiece, you can get three different magnifications out of the 12mm.  With just the barlow element, you'll turn the 12mm into a virtual 8mm (it should give you roughly a 1.5X magnification boost).   With the full barlow, you'll get roughly a 2X boost, turning the 12mm into a virtual 6mm.   It is extremely rare that the atmosphere is steady enough for that, but it is nice to have on those rare occasions, and can be useful for splitting tight double stars.   


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#23 pete123

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Posted 16 October 2018 - 10:07 AM

Thankyou that was an excellent explination and begginer friendly , that was exactly what i was after thanks


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#24 pete123

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Posted 16 October 2018 - 11:09 AM

Barlows do some good things and some not so good things.  

 

On the plus side-- first and foremost-- Barlows allow you to get double use (or perhaps even more) out of many of your eyepieces.  In addition, Barlows cause the eyepiece they are used to see a slower focal ratio than what the eyepiece would receive without the barlow.  On a fast telescope (say F/5 or faster) a 2X (or more) barlow can considerably reduce the amount of astigmatism at the field edges.  Finally, most of the tradition eyepiece designs (Plossls, Kellners, Abbe Orthoscopics, Erfles, Koenigs, etc.) are scaled designs.  This means that as the eyepiece focal length gets shorter, the amount of eye relief is reduced proportionally.  Plossls offer an excellent price/performance ratio,. but in focal lengths less than 10mm, many people find the eye relief too short for comfortable viewing.   A 2X barlow with a 15mm plossl delivers the same field as a 7.5mm plossl, but you keep the larger eye lens and eye relief of the longer eyepiece.  In fact, the barlow will actually extend the eyerelief of the original eyepiece slightly.

 

Now for the not-so-good points.   First of all, no lens is perfect: a barlow adds additional glass which means some transmission loss and possible reduction of contrast (although in well-made Barlows the amount of image deterioration should be minimal and may very well be imperceptible).   Also, as I mentioned in discussing the pros of Barlow use, a Barlow extends eye relief slightly.  This happens because the Barlow relocates the exit pupil, and for longer focal length eyepieces, this can mean pushing the eyepiece beyond its designed capability, which can lead to vignetting and the introduction of additional aberrations.  So Barlows tend to work best with shorter focal length eyepieces.   Finally, Barlows (particularly the physically longer ones) can make for awkward eyepiece positioning.   One of the nice things about an alt-az-mounted SCT is that it provides a relatively consistent eyepiece height and a Barlow can interfere with this.

 

So what does all this mean for you?

 

You have a F/10 SCT.  It's very friendly to eyepieces.   The X-Cel eyepieces you are considering are not a scaled design-- they basically already have a barlow built in.  So the only reason to want a Barlow is to get double duty out of your eyepieces.  The 25mm X-Cel is long enough it may have vignetting issues, so I'd opt for two eyepieces.

 

If budget is a concern, I'd skip the 25mm X-Cel and get a 32mm Plossl.  It has a bit wider of a true field (even if the apparent field of view is less than that of the X-Cel) and at $40-ish USD, they are a bargain.   I don't have the X-Cels, but I have full set of the very similar HD60s.   I seldom use the 25mm, preferring either a 35mm Ultima, 32mm Plossl. or 24mm ES-68.   And while the shorter HD60s have a considerable advantage in viewing comfort over similar focal length plossls, there is no such advantage on the long end.

 

On a C8 for planetary, 12mm is about where I start.   The 12mm HD60 is very good, and I would expect the X-Cel equivalent to perform similarly (I've heard it claimed that the optical design is the same).   On good nights, you'll want something shorter for planets on a C8.  If you get a barlow like the GSO shorty that has a barlow element that unscrews and can be attached directly to the eyepiece, you can get three different magnifications out of the 12mm.  With just the barlow element, you'll turn the 12mm into a virtual 8mm (it should give you roughly a 1.5X magnification boost).   With the full barlow, you'll get roughly a 2X boost, turning the 12mm into a virtual 6mm.   It is extremely rare that the atmosphere is steady enough for that, but it is nice to have on those rare occasions, and can be useful for splitting tight double stars.   

I have 1 lens at the moment which is a celestron e-lux 25mm plossl 1.25  , so u rcomend getting a 12mm x-cell and a 2x barlow lens , and at a later date i could get a 30mm x-cel ,  i was reading smewhere that once you get to 30mm and above you should buy 2" eye pieces , i can accomodate 2" eyepiece as i have a baader 2 " click lock with a 1.25 reducer.


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#25 aeajr

aeajr

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Posted 16 October 2018 - 11:31 AM

Just want to fill in the blanks here.

 

You say you have a Celestron nexstar 8 gps xlt.   I don't see that listed as one of Celestron's scopes.   There are 2 families of NexStar scopes that have an 8" OTA, both of which I believe, have a GPS option. 

 

On this page you can select the NexStar  scopes that Celestron offers.  Which one do you have?

https://www.celestro...ons/telescopes#

 

 

And BTW, your eyepieces don't have to be Celestron.  You can use any brand as long as they fit  your 2"/1.25" inch set-up.  


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