Jump to content


Photo

30mm ES 82 or 20mm ES 100?

  • Please log in to reply
49 replies to this topic

#1 Scanning4Comets

Scanning4Comets

    Markus

  • *****
  • Posts: 13500
  • Joined: 26 Dec 2004

Posted 30 May 2013 - 04:15 AM

30mm ES 82 or 20mm ES 100?

Which do you think would be a better eyepiece for my lowest power EP? I also have an Antares 1.6x barlow.

Scope = 10" F/4.7 Reflector.

#2 Illinois

Illinois

    Vanguard

  • -----
  • Posts: 2111
  • Joined: 18 Dec 2006
  • Loc: near Dixon, Illinois USA

Posted 30 May 2013 - 07:26 AM

That's not easy! Both are good! You want lowest power then go for 30mm! I think that 20mm would be good for most useful at night!

#3 Phillip Creed

Phillip Creed

    Idiot Seeking Village

  • *****
  • Moderators
  • Posts: 2086
  • Joined: 25 Jul 2006
  • Loc: Canton, OH

Posted 30 May 2013 - 08:09 AM

Markus,

I have the 30ES-82, and I borrowed an Antares 1.6X barlow one night on my 8" f/4.9. There was significant vignetting; I basically had an "18ES-82" with a 60-65 deg AFOV; hardly worth it.

Your current line-up is pretty good for low power, unless you're looking to get a really big TFOV. If you're looking for just one EP to max out your FOV, I'd lean towards the 30ES-82. The 20ES-100 should have ~34mm field stop, vs. ~42.5mm (my own personal estimate) for the 30ES-82. Your 28ES-68 should have ~32mm field stop, and the change in TFOV between that and the 30ES-82 should compliment one another nicely.

The 20ES-100 and 14ES-100 have 14.5mm listed eye relief, but the usable eye relief--especially if you wear glasses--is less than that because they recess the eye lenses. Explore Scientific also recesses the eye lens of the 30ES-82, but the listed 21mm eye relief helps offset it. I've had a much easier time seeing the full FOV in the 30ES-82 with my glasses on than the 14ES-100.

Clear Skies,
Phil

#4 Achernar

Achernar

    Cosmos

  • *****
  • Posts: 9013
  • Joined: 25 Feb 2006
  • Loc: Mobile, Alabama, USA

Posted 30 May 2013 - 09:43 AM

Be aware both of these eyepieces are HUGE, the 30mm ES 82 degree is as big as a can of veggies and the other one is even bigger. You may need to use a counterweight to fix the possible balance issue either may create. Both are superb eyepieces, especially if you do not need to wear eyeglasses while observing.

Taras

#5 Damo636

Damo636

    Ranger 4

  • -----
  • Posts: 316
  • Joined: 16 Aug 2011
  • Loc: Co Fermanagh, Northern Ireland

Posted 30 May 2013 - 09:46 AM

Markus

If by lowest power you are aiming for max true fov, I would say go with the 30mm. I've owned this eyepiece and it's a superb for that purpose. That said, when I eventually acquired the 21 Ethos, I found I rarely reached for the 30mm and have since sold it (as well as a 31 Nagler!) Even though they both showed slightly more sky (1.6° vs 1.4°), they just couldn't match the quality of the view in the 21 Ethos. The 20 ES 100° is reported to be excellent, so I guess if it came down to a choice between the two, I would go with the 20mm every time.

#6 MRNUTTY

MRNUTTY

    Surveyor 1

  • *****
  • Posts: 1859
  • Joined: 22 Nov 2011
  • Loc: Mendon, MA

Posted 30 May 2013 - 12:33 PM

ES100/20, more mag!

#7 hfjacinto

hfjacinto

    I think he's got it!

  • *****
  • Posts: 11802
  • Joined: 12 Jan 2009
  • Loc: Land of clouds and LP

Posted 30 May 2013 - 12:47 PM

I used both and have the 31MM T5 and the 20MM ES and the ES is a better eyepiece and gets more use.

#8 Matt Wallin

Matt Wallin

    Explorer 1

  • *****
  • Posts: 81
  • Joined: 29 Jan 2012
  • Loc: Portland, OR

Posted 30 May 2013 - 01:04 PM

I have both these eyepieces, I find myself using the 20mm significantly more often, especially at my semi-dark site, it is a spectacular eyepiece with amazing contrast and correction. Some objects just need the max field though, so the 30mm gets some playing time too. Besides the exit pupil size, one reason I often go for the 20mm 100* is that the coma is objectionable to me at the edges of the field with the 30mm 82* in my 10" f/5 scope. Having recently used my 30mm 82* with a borrowed ParaCorr, I was really impressed with how much more I enjoyed the view through it. I can say that I will reach for the 30mm 82* much, much more often after the AstroTech Coma Corrector that I ordered (back ordered, I should say) arrives.

#9 Scanning4Comets

Scanning4Comets

    Markus

  • *****
  • Posts: 13500
  • Joined: 26 Dec 2004

Posted 30 May 2013 - 04:06 PM

Thanks for the replies!

So far, it looks like the 20mm ES is reigning the best!

Will keep you all posted and write up a report if I get it.

Cheers,

#10 Starman81

Starman81

    Surveyor 1

  • *****
  • Moderators
  • Posts: 1919
  • Joined: 06 Mar 2008
  • Loc: Metro Detroit, MI, USA

Posted 30 May 2013 - 04:17 PM

Mark, I have not heard your comments on the ES68 28mm in your scope, other than you are 'looking for better edge correction'...

#11 beatlejuice

beatlejuice

    Surveyor 1

  • *****
  • Posts: 1553
  • Joined: 05 Apr 2011
  • Loc: Hamilton, ON,Canada

Posted 30 May 2013 - 05:55 PM

I'm not sure Mark:
30mm gives 2.05FOV and 3.30 square degrees. 20mm gives 1.67FOV and 2.19 square degrees.

M32,M31 and M110 just fit in same FOV of 30(a beautiful sight). There are quite a few other situations where that 2.05FOV is advantageous.
But there are also numerous objects that will benefit from the darker background and where the smaller FOV will not be a hindrance. Large open clusters come to mind, but it depends on how you like your objects to be framed in the eyepiece as well. More sky or less sky.

Nevertheless I am rooting for the 20 so I can try it out :grin:

Eric

#12 bherv

bherv

    Surveyor 1

  • *****
  • Posts: 1609
  • Joined: 10 Mar 2006
  • Loc: WMass

Posted 30 May 2013 - 07:41 PM

I have both in my collection, but if I had to pick one I would go with the 20. You will get more use out of it.
Barry

#13 Scanning4Comets

Scanning4Comets

    Markus

  • *****
  • Posts: 13500
  • Joined: 26 Dec 2004

Posted 30 May 2013 - 08:05 PM

Mark, I have not heard your comments on the ES68 28mm in your scope, other than you are 'looking for better edge correction'...


Hi Syed,

Heaps of coma shows in the 28mm ES, which does come from the mirror. In trying Eric's 30mm Meade UWA, I could hardly see any coma at all, and the same goes for the 20mm ES 100 which I have tried a few times. Eye relief is very comfortable in the 28mm ES and it also barlowed nice in the 2" ES focal extender which I do not own. I prefer the views and edge correction I get from the 30mm Meade 5000 UWA & also the 20mm ES 100 over the 28mm ES 68 in my scope.

I'm not sure Mark:
30mm gives 2.05FOV and 3.30 square degrees. 20mm gives 1.67FOV and 2.19 square degrees.

M32,M31 and M110 just fit in same FOV of 30(a beautiful sight). There are quite a few other situations where that 2.05FOV is advantageous.
But there are also numerous objects that will benefit from the darker background and where the smaller FOV will not be a hindrance. Large open clusters come to mind, but it depends on how you like your objects to be framed in the eyepiece as well. More sky or less sky.

Nevertheless I am rooting for the 20 so I can try it out

Eric


Hi Eric,

You are correct in both instances as the 30mm ES will be excellent for framing certain targets and have a wider FOV! The 20mm ES 100 will have higher contrast from more power and less FOV! Very hard to decide which one, but I am leaning more towards the 20mm ES and I might be getting a 14mm ES 100 to add to my collection as well, which means the sale of my 10mm Pentax XW.

I have both in my collection, but if I had to pick one I would go with the 20. You will get more use out of it.
Barry


I am leaning MORE towards the 20mm ES for higher contrast and a darker background and I can still use it as a finder EP as well! The pic I have added shows what I see in the 28m ES in my scope. I do NOT see this in the 20mm ES 100 or 30mm Meade 5000 UWA!

Cheers,

Attached Files



#14 beatlejuice

beatlejuice

    Surveyor 1

  • *****
  • Posts: 1553
  • Joined: 05 Apr 2011
  • Loc: Hamilton, ON,Canada

Posted 30 May 2013 - 10:40 PM

The pic I have added shows what I see in the 28m ES in my scope. I do NOT see this in the 20mm ES 100 or 30mm Meade 5000 UWA!



I think there may be an undiscovered comet in there somewhere :roflmao:

Eric

#15 Starman81

Starman81

    Surveyor 1

  • *****
  • Moderators
  • Posts: 1919
  • Joined: 06 Mar 2008
  • Loc: Metro Detroit, MI, USA

Posted 30 May 2013 - 10:59 PM

In the end, it's your call, but I put my vote in for the ES100 20... If getting the ES100 14 means parting with the XW 10, I say resist. You already know you love the XW 10, make sure you love the ES100 series before you leap, so the best way is to acquire and use the ES100 20 for a good long time to make that judgement.

#16 Scanning4Comets

Scanning4Comets

    Markus

  • *****
  • Posts: 13500
  • Joined: 26 Dec 2004

Posted 30 May 2013 - 11:16 PM

In the end, it's your call, but I put my vote in for the ES100 20... If getting the ES100 14 means parting with the XW 10, I say resist. You already know you love the XW 10, make sure you love the ES100 series before you leap, so the best way is to acquire and use the ES100 20 for a good long time to make that judgement.


I have already tried the 20mm & 14mm ES and I liked both...A LOT, and would use the 14mm ES 100 to frame more targets than I would with the 10mm XW.

I think there may be an undiscovered comet in there somewhere, :roflmao:

Eric


SEVERAL actually, LOL !!!

Cheers,

#17 Scanning4Comets

Scanning4Comets

    Markus

  • *****
  • Posts: 13500
  • Joined: 26 Dec 2004

Posted 30 May 2013 - 11:58 PM

However, even though I have big thoughts about getting the 20mm ES 100, I would also like the 30mm ES 82!

I am still not positive on a decision between the 30mm ES 82 and the 20mm ES 100....I still have both bouncing back & forth in my head LOL.

#18 stratocaster

stratocaster

    Messenger

  • *****
  • Posts: 420
  • Joined: 27 Oct 2011

Posted 31 May 2013 - 01:17 AM

I have both and intend to keep both. For those of us who own the 30mm we likely purchased it because it provides the widest tfov available in the ES line. That doesn't change with the 20mm 100.

Now, I did sell my ES 24 82 because of the ES 20 100. But I'm not going to let go of the 30mm because when I want to look at those large DSOs I want the largest tfov I can get. So I don't view these two eyepieces as either/or at all.

#19 Scanning4Comets

Scanning4Comets

    Markus

  • *****
  • Posts: 13500
  • Joined: 26 Dec 2004

Posted 31 May 2013 - 01:25 AM

Good points Stratocaster!

#20 Messyone

Messyone

    Viking 1

  • -----
  • Posts: 531
  • Joined: 02 May 2012
  • Loc: Down Under

Posted 31 May 2013 - 03:54 AM

For what it's worth I sold 7 ES 82* and 68* eyepieces to fund three ES 100* eyepieces, 9, 14 and 20mm. Never regretted it one bit. As most of my observing is done in my LP backyard it was an easy decision. The exit pupil's did it for me! The 100's are great next to my four XW's, and at a dark site ....wow is all I can say.
Join the 100 degree revolution :lol: and if you can, get the ES 30 82* too.
Now if there is a cloud busting eyepiece out there......

#21 ibase

ibase

    Vendor Affiliate

  • *****
  • Vendors
  • Posts: 4492
  • Joined: 20 Mar 2008
  • Loc: Manila, Philippines 121*E 14*N

Posted 31 May 2013 - 04:40 AM

Mark, so you're slowly pushing toward the 100° conversion plan, yes the 100ES20mm would be a great start! It's about as large as the 100ES14mm shown below, massive! :)

Posted Image
ES100 14mm

Best,

#22 star drop

star drop

    contra contrail

  • *****
  • Moderators
  • Posts: 70238
  • Joined: 02 Feb 2008
  • Loc: Snow Plop, WNY

Posted 31 May 2013 - 08:59 AM

If the 30mm Explore Scientific 82° eyepiece is as good as the 30mm Meade UWA then I would say get it and also the 20mm Explore Scientific 100°. In my case I spend more time with the 30mm than the 20mm due to local seeing conditions. With a Paracorr in place in my telescope the 30mm yields 121x magnification, the 20mm 181x, the 14mm 259x and the 9mm 403x. All of the eyepieces provide a dark background since I now observe in a rural area (green zone).

#23 John Huntley

John Huntley

    Viking 1

  • *****
  • Posts: 925
  • Joined: 16 Jul 2006
  • Loc: South West England

Posted 31 May 2013 - 02:52 PM

I have an ES 20mm 100 and a Nagler 31mm. Becuase I have some light pollution to contend with the ES 20 / 100 spends more time in use than the big Nagler does because the background sky looks darker with it.

I'm keeping the big Nagler (which I owned before I got the ES 20 / 100) though because it's sometimes great to have that widest possible field, eg: framing both sides of the Veil Nebula when used with my Vixen ED102SS.

#24 Scanning4Comets

Scanning4Comets

    Markus

  • *****
  • Posts: 13500
  • Joined: 26 Dec 2004

Posted 31 May 2013 - 04:26 PM

Well,

I took the plunge! I am getting the 20mm ES 100 after all !!!

Next will be the 14mm ES 100! :yay:

#25 Damo636

Damo636

    Ranger 4

  • -----
  • Posts: 316
  • Joined: 16 Aug 2011
  • Loc: Co Fermanagh, Northern Ireland

Posted 31 May 2013 - 04:49 PM

Congrats Markus, good decision :band:
Just a thought, but won't the 20mm 100* leave the 22 LVW all but redundant? My thinking is this, sell the Vixen along with the 28mm ES and replace with the 30mm 82*! What a combo those two would make :shocked:






Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics