Jump to content

  •  

CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.

Photo

Which size eyepiece next?

  • Please log in to reply
14 replies to this topic

#1 Liam337

Liam337

    Lift Off

  • -----
  • topic starter
  • Posts: 3
  • Joined: 05 Mar 2020

Posted 23 February 2021 - 06:02 PM

I have had my telescope (114mm A, 900mm FL) now for a year, and I think it is time for a new eyepiece. I have a 25mm, 10mm, and a 2X Barlow. I was wondering what would be the next best size to get. Also I wanted to get a nice one so are there any good brands that you recommend.

Thanks! 


  • scotsman328i and aeajr like this

#2 SeattleScott

SeattleScott

    Voyager 1

  • *****
  • Posts: 10,729
  • Joined: 14 Oct 2011

Posted 23 February 2021 - 06:24 PM

Two considerations. Could go wider, with a 32 Plossl or 25 Xcel LX or similar to get about a 20% wider view at low power. But you also have a gap between 10mm and 5mm (10mm plus barlow). You could use a 7mm to fill that gap. A 7 Xcel LX would be one option.

Ok so yo said you want to try a nice eyepiece. How nice? Your Plossls run about $35-40. An Xcel LX is around $90 so I suggested that as a significant upgrade without being way more expensive. But a $200 APM 24 UFF would be an even better option than the 25 Xcel LX. A $300 Pentax 7XW would be even better at 7mm. You have a cheap scope so I am guessing you don’t want eyepieces that cost hundreds of dollars, hence I led with the Xcel LX. But maybe you are a go big or go home guy?

Scott

#3 f74265a

f74265a

    Viking 1

  • -----
  • Posts: 721
  • Joined: 19 Oct 2020

Posted 23 February 2021 - 06:36 PM

Budget is key
If you can tolerate the price, a tele vue 15 delite would give 60x and 120x with Barlow
That would slot in well I think with your other gear. And it would work on any upgraded scope you get in the future

#4 Starman1

Starman1

    Vendor (EyepiecesEtc.com)

  • *****
  • Vendors
  • Posts: 49,432
  • Joined: 23 Jun 2003
  • Loc: Los Angeles

Posted 23 February 2021 - 06:54 PM

I have had my telescope (114mm A, 900mm FL) now for a year, and I think it is time for a new eyepiece. I have a 25mm, 10mm, and a 2X Barlow. I was wondering what would be the next best size to get. Also I wanted to get a nice one so are there any good brands that you recommend.

Thanks! 

So you have 36x and 90x.

Well, you could definitely use at least 1 more eyepiece: 15mm (60x).

With Barlow you then have 120x (will be used often) and 180x (won't be used much if at all)

Now, of course, that is +/- on the 15mm focal length.  Anything in the 14-16mm range is fine (56-64x)

So, what stands out in that range?

Astrotech 15mm Paradigm eyepiece (from our sponsor Astronomics) 60°

BST 15mm Starguider ED 60°

For more $:

Meade UHD 15mm 65°

APM UltraFlat Field 15mm 65°

and more again:

Stellarvue 15mm 82°

All would be great in your scope.


  • scotsman328i likes this

#5 scotsman328i

scotsman328i

    Apollo

  • *****
  • Posts: 1,164
  • Joined: 03 Jan 2006
  • Loc: Charleston, South Carolina

Posted 23 February 2021 - 07:04 PM

I have had my telescope (114mm A, 900mm FL) now for a year, and I think it is time for a new eyepiece. I have a 25mm, 10mm, and a 2X Barlow. I was wondering what would be the next best size to get. Also I wanted to get a nice one so are there any good brands that you recommend.

Thanks! 

Liam, a lot falls on the budget you have and what you want to pay. You can get premium glass of $350 or more budget minded glass as Don (Starman1) recommended. He’s given you some great choices. 14mm-16mm would be your ticket as you do Barlow. The 17mm would be in the middle of the 25mm and 10mm you own now, but barlowed it is too close to the 10mm you already own as a 17mm would Barlow to 8.5mm. Don said it best, aim at getting a 15mm. That will give you a very usable 7.5mm when barlowed. Not too high powered, but high powered enough for the vast majority of the conditions you will view in. You will also find that 15mm is still a very comfortable eyepiece to use, plus barlowed it will give you a touch more eye relief also. Good Luck choosing and do keep us posted! waytogo.gif



#6 f74265a

f74265a

    Viking 1

  • -----
  • Posts: 721
  • Joined: 19 Oct 2020

Posted 23 February 2021 - 07:11 PM

That’s 3 out of 3 at 15mm.

#7 SeattleScott

SeattleScott

    Voyager 1

  • *****
  • Posts: 10,729
  • Joined: 14 Oct 2011

Posted 23 February 2021 - 07:27 PM

That’s 3 out of 3 at 15mm.

Hey I didn’t advocate for a 15! 😃

I figured the 25 barlowed was close enough so I went straight for 7mm. But a 15 or 14 with a barlow works too.

Scott
  • scotsman328i likes this

#8 alanajones

alanajones

    Lift Off

  • -----
  • Posts: 10
  • Joined: 30 Mar 2020

Posted 23 February 2021 - 07:29 PM

You might wish also to consider looking at it from some different perspectives as follows:

 

i) Its not just about the focal length, first work out the true fields of view of your current eyepieces and decide what field(s) of view might be next of interest to you.

 

ii) There will probably be plenty of objects smaller than your current eyepiece collection and plenty of single objects (or groups of objects) which would benefit from a wider field of view. Take a look through the main object catalogues and see if that helps which direction you want to go (wider or narrower view).

 

iii) My personal preference is to double or halve the true field of view for every new piece of equipment I buy. It might be worth considering your preference on what size steps you want to take so you see enough benefit from your (possibly costly) outlay.

 

iv) If I want narrower fields of view and have top quality eyepieces I tend to buy different top-quality barlows to go with them rather than investing in new expensive eyepieces, but as was said above it depends a lot on what budget range you are in to start with.

 

Hope this helps



#9 f74265a

f74265a

    Viking 1

  • -----
  • Posts: 721
  • Joined: 19 Oct 2020

Posted 23 February 2021 - 07:33 PM

Hey I didn’t advocate for a 15! 😃

I figured the 25 barlowed was close enough so I went straight for 7mm. But a 15 or 14 with a barlow works too.

Scott


You’re right
I can’t count tonight
  • SeattleScott likes this

#10 sportsmed

sportsmed

    Ranger 4

  • *****
  • Posts: 332
  • Joined: 01 Aug 2012
  • Loc: Hot Springs, AR

Posted 23 February 2021 - 07:45 PM

Yea I would go with something between 15-18mm with a barlow thats also a 7.5mm to 9mm which you could use. Not sure your budget though or how wide you want your FOV? So many options in those focal lengths but until we know what budget etc you are at not sure what to suggest. But if the two eyepieces you have came with the scope then most eyepieces will be an upgrade.



#11 Ohmless

Ohmless

    Viking 1

  • *****
  • Posts: 527
  • Joined: 05 Jun 2017
  • Loc: Houghton Lake, Michigan USA

Posted 23 February 2021 - 09:55 PM

If the 9mm is a plossl, then i would look to not use it due to very short eye relief.  If I was in your shoes, I'd use the 25mm with a 18mm paradigm and the 12mm paradigm.  both of them are solid eyepieces and relatively inexpensive at 60 bucks.

 

25mm would be the low power finder that is good at large objects at 32x.  I wouldn't barlow this eyepiece for simplicity.

the 18mm would give over a 1 degree field of view at 50x(good for medium size deep sky objects.)

the 12mm would provide 75x for a bit higher magnification and would be your maximum magnification eyepiece for planets when barlowed.

 

Another option if budget is strict would be to get the 15mm paradigm(I love mine) or 15mm celestron omni plossl with a 9mm Svbony 68 degree eyepiece off ebay.  The Svbony is one of the least expensive eyepieces in the game.

 

if budget allows and if you don't have one already, I would also get a celestron collimation eyepiece or a laser collimation tool.  Both are cheap.



#12 Dave Mitsky

Dave Mitsky

    ISS

  • *****
  • Moderators
  • Posts: 95,551
  • Joined: 08 Apr 2002
  • Loc: PA, USA, Planet Earth

Posted 24 February 2021 - 01:31 AM

My vote would go to the already mentioned 15mm Astro-Tech Paradigm Dual ED eyepiece.

 

https://www.astronom...gm-dual-ed.html

 

https://www.cloudyni...y_discount.html



#13 Starman1

Starman1

    Vendor (EyepiecesEtc.com)

  • *****
  • Vendors
  • Posts: 49,432
  • Joined: 23 Jun 2003
  • Loc: Los Angeles

Posted 24 February 2021 - 02:03 AM

If the goal is to have each higher power yield a true field of half the size, and all your eyepieces have the same apparent field,

then divide each eyepiece focal length by 1.414 to get the next shorter focal length.

I.e. 30mm, 21mm, 15mm, 10.6mm, 7.5mm

That makes a 30/21/15 set and a 2X Barlow a good combination.

Of course, if your eyepieces all have different apparent fields, then that idea flies out the window.

But the math works out if all eyepieces are the same type.



#14 aeajr

aeajr

    Voyager 1

  • *****
  • Posts: 14,890
  • Joined: 26 Jun 2015
  • Loc: Long Island, New York, USA

Posted 24 February 2021 - 04:44 PM

I have had my telescope (114mm A, 900mm FL) now for a year, and I think it is time for a new eyepiece. I have a 25mm, 10mm, and a 2X Barlow. I was wondering what would be the next best size to get. Also I wanted to get a nice one so are there any good brands that you recommend.
Thanks!

What scope do you have? 114 mm A, 900 FL doesn't tell me much.

Can you provide a link?

Refractor, reflector? Appears to be F 7.9 so not likely an SCT or Mak.


Different types of Telescopes
https://telescopicwa...-of-telescopes/



Can it take 2" eyepieces? 1.25" eyepieces? Or does it use .965" eyepieces?


I presume the eyepieces you have are the ones that came with the scope. Do you know what type they are? Typically they would be:


  • Ramsden
  • Huygens
  • Kellners
  • Modified Achromats
  • Plossls
Knowing what you have would help us understand your expectations. A Plossl would be an upgrade from zany of the others, for example.


What is your budget? "nice eyepieces" can run $300 or more, each.


What would you want from this new eyepiece?
  • Higher power?
  • Wider field of view?
  • better eye relief?
  • How about a zoom eyepiece? (my favorite)
Understanding Telescope Eyepieces- There are recommendations, based on budget,
but the meat of the article is about understanding the considerations and specifications
to know when selecting eyepieces.
https://telescopicwa...cope-eyepieces/


Understanding and using a Barlow Lens
https://telescopicwa...ens-and-how-to/


Need more information. Read the articles first and you will be in a better position to answer the questions and give us some guidance so we can help you.

Edited by aeajr, 24 February 2021 - 06:17 PM.


#15 f74265a

f74265a

    Viking 1

  • -----
  • Posts: 721
  • Joined: 19 Oct 2020

Posted 24 February 2021 - 05:19 PM

I’ll bet it is a reflector.


CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.


Recent Topics






Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics