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ES100 20mm & 25mm v TV Ethos 21mm & Nagler 31mm respectively

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#1 25585

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Posted 20 February 2019 - 08:00 AM

How do the ES100 20 & 25 compare with Tele Vue's 21mm Ethos and 31mm Nagler respectively ?

 

For TFOV the 20 & 21 are close, but a world away in price.

 

The 25 100 and 35 Nr.T5 have close TFOV, and are closer in price, both heavy, unlike the other pair.

,

 

Attached Thumbnails

  • astronomy_tools_fov (35).png

Edited by 25585, 20 February 2019 - 08:02 AM.


#2 Jeff Struve

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Posted 20 February 2019 - 08:08 AM

Well.... I compared head to head the 100° 20mm ES and the TV 21mm Ethos... I owned them both for a while... I liked the TV a slightly bit better. The ES had a bit better contrast, but the TV seemed better color corrected and was much clearer to the edge. I ended up selling the ES...

 

I do own the 21mm Ethos and the 31mm Nagler. I must admit that I don't use the 31 much as I prefer larger FoV... but the 31 is kinda of an industry standard/legacy... this says it better than I:

 

https://www.cloudyni...ini-comparison/

 

 

 

Jeff


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#3 Tank

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Posted 20 February 2019 - 12:58 PM

Only one i haven't tried is the 25mm 100

 

31T5 i can see how one may not need and would prefer the 21 Ethos over it but would be dependent on the scope in use

 

-scopes giving less than approx. +/- 2 degree FOV i think the 31T5 shines

-scope that give more FOV i feel that the 31T5 is not really necessary and the 21 Ethos would be my first choice

 

21 Ethos vs 20 ES 100

-Ethos wins for me, the 20 ES 100 is a nice EPs but a bit greyish field background vs the Ethos

 

these are all nice EPs by the way and if you can afford the 21 Ethos works great side by side with the 31T5


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#4 rkelley8493

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Posted 21 February 2019 - 03:43 PM

I've got the 20mm ES and have never looked thru an Ethos, but I would agree with Tank that it does have a grayish field background compared to my 17mm Nagler. Eye relief is a little short as well, but I still enjoy looking thru it. It's very immersive. 



#5 rustynpp

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Posted 21 February 2019 - 07:36 PM

I've got the 20mm ES and have never looked thru an Ethos, but I would agree with Tank that it does have a grayish field background compared to my 17mm Nagler.

I would bet the darker background has more to do with the increased magnification/decreased exit pupil than it does the EP design.


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#6 rkelley8493

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Posted 22 February 2019 - 09:45 AM

I would bet the darker background has more to do with the increased magnification/decreased exit pupil than it does the EP design.

You could be right. I had a chance to use it last night (first time in almost 2 weeks) and spent some time with it on the Double Cluster and NGC 2841 (Galaxy in Ursa Major). The double cluster's star colors really popped with white, blue, and orange stars, and galaxy 2841 was very prominent (similar in appearance to M81) despite the light pollution.



#7 junomike

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Posted 22 February 2019 - 01:06 PM

I found the ES 20mm 100 great but the 21E better still.

As for the 31T5, many EP's have tried but none have matched it IMO.

I have a 25mm 100° on the way and I'm hoping  it's higher magnification (with similar FOV) might

de-throne the "King", but alas I have my doubts...


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#8 MitchAlsup

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Posted 22 February 2019 - 04:34 PM

I have not looked through a 20ES100, but I have the other three.

 

For me, and at my age (66) I find the smaller exit pupil of the 25ES100 a significant advantage over my 31NT5.

No, it is not as well corrected, and has other issues (ring of fire,...) but being able to keep the FoV of the 31NT5 and having the entire 20" F/4 aperture reach into my eye rather than illuminating my eye's pupil is advantageous.

 

Since I got the 25ES100, the 31NT5 as been resting in its original packaging box.


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#9 junomike

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Posted 22 February 2019 - 07:39 PM

I have not looked through a 20ES100, but I have the other three.

 

For me, and at my age (66) I find the smaller exit pupil of the 25ES100 a significant advantage over my 31NT5.

No, it is not as well corrected, and has other issues (ring of fire,...) but being able to keep the FoV of the 31NT5 and having the entire 20" F/4 aperture reach into my eye rather than illuminating my eye's pupil is advantageous.

 

Since I got the 25ES100, the 31NT5 as been resting in its original packaging box.

I'm about 15yrs your junior and  I also have an F4 OTA (12") which I frequently use for wide DSO's with the  31T5 although I'm sure I'm  loosing a little Aperture.  The 25mm 100 will definitely better in that regard.



#10 Tank

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Posted 23 February 2019 - 05:40 PM

I would bet the darker background has more to do with the increased magnification/decreased exit pupil than it does the EP design.


Not sure about the ES 20 100
Compared to
21 Ethos
17 Ethos
22T4
20T2
24 Pan
17es92
Etc WF EPs
20 es 100 seems to have greyish background image of them
Don't get me wrong the 20es100 is a very good EP but I lean towards others personal preference
One note on this is more stray light moon sky glow etc the ES becomes increasingly greyer background
I noticed that the 30es82 is Really guilty of this


Edited by Tank, 23 February 2019 - 05:50 PM.

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#11 ACG

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Posted 28 February 2019 - 01:03 PM

I have the ES25mm with other ES (30 of 3 ", 17 and 12 of 92º). I have compared the ES25 several times with an Ethos21, and sincerely the 25 is superior to the E21, in all the telescopes in which I have used them. El30 of 3 "is also superior to nagler31. For my televue is lagging behind regarding ES. The 17th and the 12th are also spectacular.

 

Regards

ACG


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#12 John Huntley

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Posted 28 February 2019 - 06:17 PM

I used to have an ES 20 / 100 and liked it a lot. I was tempted by a great deal on an Ethos 21 though and found it slightly better in terms of edge correction and background darkness. I also found seeing the full field of view easier to see with the Ethos - I needed to fold the eyecup of the ES 20 / 100 down but could keep it up with the Ethos 21. I don't wear glasses when observing.

 

I also have the Nagler 31 and have had that for many years now. It does not get as much use as the Ethos 21 does because the latter is a more effective deep sky tool under my skies.

 

I've had quite a few nights with my 12 inch dobsonian when the 21mm Ethos is the only eyepiece that I've used.

 

I can't comment on the ES 25mm 100 because I've not used one.


Edited by John Huntley, 28 February 2019 - 06:17 PM.

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#13 faackanders2

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Posted 28 February 2019 - 10:00 PM

Not sure about the ES 20 100
Compared to
21 Ethos
17 Ethos
22T4
20T2
24 Pan
17es92
Etc WF EPs
20 es 100 seems to have greyish background image of them
Don't get me wrong the 20es100 is a very good EP but I lean towards others personal preference
One note on this is more stray light moon sky glow etc the ES becomes increasingly greyer background
I noticed that the 30es82 is Really guilty of this

Based on exit pupil alone, the background/constrast would be best/darkest for the highest power:

17es92=17 Ethos  darkest background/most contrast

20T2=ES 20 100

21 Ethos
22T4
24 Pan
30es82 lightest background/least contrast

 

Background/contrast is part of what makes the majesty factor, the other aspect is power magnification for seeing detail.  If you can match same TFOV, the higher power would have the greater majesty factor and wider AFOV.

Also once the eyepiece exit pupil exceeds the observers eye night time/scotopic pupil (wasted light falling on observers iris), then the only advantage would be gaining wider TFOV till you reach 40-41mm  68-70 AFOV in a 2" eyepiece.  The only way to get a wider TFOV would be to go with a larger focuser/larger barrel eyepiece with and even greater exit pupil and lighter background (and this is most practical for refractors without a central obstruction). 



#14 faackanders2

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Posted 28 February 2019 - 10:09 PM

I have the ES25mm with other ES (30 of 3 ", 17 and 12 of 92º). I have compared the ES25 several times with an Ethos21, and sincerely the 25 is superior to the E21, in all the telescopes in which I have used them. ES30 of 3 "is also superior to nagler31. For my televue is lagging behind regarding ES. The 17th and the 12th are also spectacular.

 

Regards

ACG

Since you consider 3" ES30mm 100AFOV superior to 2" 31mm 82AFOV Nagler, would you consider selling the 31mm Nagler, or do you keep it for your 2" telescopes that don't have 3" focusers.

 

For example I have a 2" 40mm 70AFOV MK70 University Optics Koening as my widest TFOV eyepiece, but still keep a 1.25" 40mm Possil(?) finder eyepiece for 1.25" only telescopes.



#15 ACG

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Posted 01 March 2019 - 02:02 AM

The Nagler 31 has been sold for some time. Another person will be enjoying it, I am however delighted with the 3. "For my 2" telescopes the choice is very easy, ES25 mm and a Kasai Konig 40mm, just like yours. Keep that eyepiece as a real treasure because it is finer than the Pan41. I've also checked that several times
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#16 hakann

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Posted 01 March 2019 - 04:30 AM

I checked Ethos 13 vs a equal ES in a 18” f/4.5 CZ on M13 some years ago and the Ethos wins easy, that said vs price the ES is not bad but not a crisp and more greyish.
I has not been a fan of Naglers personally.
Tested the N31 vs E21 in a 25” and ok wider but contrast is way better on the Ethos.
I has the Ethos series but prefere Nikon HW’s is at max 17 mm.
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