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8mm Delos or 8mm Ethos for Immersive EXPERIENCE

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#1 rkelley8493

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Posted 15 April 2019 - 06:26 PM

I'm looking at adding another eyepiece and think 8mm is a sweet spot for mid power in my Apo & high power for my SCT. So the question is.. Ethos or Delos? Lately I've been on a bender for the large eye lens and long eye relief for an immersive experience. So would the Ethos be what I'm looking for, or does the Delos fit the bill? Field of view aside, how do these eye-p's compare in a head-2-head in terms of color, contrast, viewing comfort, and "spacewalk" experience? Let's pretend they cost the same and we're doing a double blind experiment with an F/7 130mm  refractor.



#2 Tank

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Posted 15 April 2019 - 06:39 PM

Both are different
Both are great
Delos a bit deeper/bit sharper
I prefer the Delos because big eyelens and eyerelief is alot
Preferences
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#3 jeremiah2229

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Posted 15 April 2019 - 06:40 PM

Oh wow, this is a great question and since I suffer from Ethoitis I maybe can help.

 

If you can't use the Ethos with the cup down then get the Delos. If you can use the Ethos with the cup down then forget about the Delos. The Ethos series has to be the best from Tele Vue, just my right eye speaking. Ethos with cup down is Pana Vision. Remarkable eyepiece and yes it is immersive.

 

Peace...


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#4 GeneT

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Posted 15 April 2019 - 07:27 PM

I own both. I view through a 12.5 inch, F5 Portaball. I prefer the Delos for planetary viewing. It has an AFOV of 72 degrees, and 20mm of eye relief, plenty if you like to view while wearing glasses. The Ethos has an AFOV of 100 degrees and eye relief of 15mm. That is pretty tight if you view while wearing glasses. I have no astigmatism, so I take my glasses off when at the eyepiece. The 100 degrees of AFOV for the Ethos is a significant bump up to the 72 degrees of the Delos. Both the Ethos and Delos are about equal when doing planetary viewing, however the Delos is a tad sharper.   


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#5 csrlice12

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Posted 15 April 2019 - 07:33 PM

Own both, and at 8mm go with the ethos if you don't wear glasses when viewing.  That's my opinion and I'm sticking to it.  Although I don't seem to be the only one who owns both so that should tell you something....like who the eyepiece nuts are.


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#6 rkelley8493

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Posted 15 April 2019 - 07:55 PM

I don't wear glasses, but I do view with the eye cup folded down. Makes it easier to take in the full field of view. After months/years of viewing with the eye cup folded up, I stumbled on how much better it is folded down by accident. I folded the guard down to put the cap back on, and something got me sidetracked. When I glanced back down into the lens, it was like going from antenna TV to ultra-high def. It's like outer space was jumping out of the eye-p bigshock.gif


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#7 jeremiah2229

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Posted 15 April 2019 - 08:09 PM

Then you should appreciate the Ethos. Just be warned that no information is supplied that warns of the "consequences of extended use" of the eyepieces. And the only antidote seems to be more Ethos serum.

 

 

Peace...


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#8 Allan Wade

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Posted 15 April 2019 - 08:56 PM

Under average observing conditions you won’t see any difference optically between the Ethos and Delos, so the difference in FOV and eye relief are the two main factors that seperate the eyepieces. When I’ve compared the two under very good observing conditions, the Delos starts to reveal a sharper more contrasty image with less scatter. In big scopes the gap becomes more significant.

 

I built my wide field eyepiece set with the 21/17/13 Ethos and 10/8/6/4.5/3.5 Delos. My reasoning was the larger field of view is more important at low power when I’m trying to frame large objects inside the FOV, while the optical performance at large exit pupils is less critical. By the time I get to higher power I’m looking at smaller objects or details, where the FOV is not important, but maximum optical performance is.


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#9 Procyon

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Posted 15 April 2019 - 10:29 PM

An 8mm will give you 115x magnification and a 1.15mm exit pupil, hmmmm, tough one. Probably the Delos if you're going for Planetary, Globulars and resolution with this focal length.

But like others said, if you like viewing with the eyeguard downwards, perhaps the Ethos if you want the wider fov.

The refractor will already have the wide fov though.

Otherwise Delos for more comfort and a bit deeper resolution. A Delos really penetrates inside and around Globulars nicer than most ep's. Best would be to try both and keep the one you like most.

It's the only way to be sure. :)

Edited by Procyon, 15 April 2019 - 10:40 PM.

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#10 rkelley8493

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Posted 15 April 2019 - 10:39 PM

I think I'll go Delos on this one. Resolution & detail is more important to me than a wide FOV, at this focal length anyways. I've spent the last couple nights mostly on M3 globular cluster w/ Delos & Pentax. M3 is actually what I had in mind for an 8mm eye-p. Then planet season is right around the corner.. Jupiter & Saturn will be at opposition in a couple more months!


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#11 Procyon

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Posted 15 April 2019 - 11:01 PM

The 8mm Delos has been great for me and I will buy it again, not sure why I even sold it. I thought the 9mm ES 100 would make for a decent replacememt, but couldn't use it because of eye placement issues.

I never had an ep that can resolve Globulars so easily at 350x, from a Bortle 8 zone..on below average nights.

I'm happy I picked up a 10mm TV Delos last December and can't wait to try it on Planets and Globulars at 1mm Exit Pupil and 280x magnification.

Happy hunting!

Edited by Procyon, 15 April 2019 - 11:10 PM.

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#12 jeremiah2229

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Posted 15 April 2019 - 11:41 PM

An 8mm will give you 115x magnification and a 1.15mm exit pupil, hmmmm, tough one. Probably the Delos if you're going for Planetary, Globulars and resolution with this focal length.

But like others said, if you like viewing with the eyeguard downwards, perhaps the Ethos if you want the wider fov.

The refractor will already have the wide fov though.

Otherwise Delos for more comfort and a bit deeper resolution. A Delos really penetrates inside and around Globulars nicer than most ep's. Best would be to try both and keep the one you like most.

It's the only way to be sure. smile.gif

This is interesting and shows us how each of us have different eyes and no one shoe fits all when it comes to the differences of our eye sight. I too thought this very same thing (though I use the XWs here) until I tried the first Ethos. And like the OP I have a SV130EDT here and with the XW 10mm M13 is a treat but when I first dropped the Ethos 10mm to compare I knew the Ethos was my "new" globular eyepiece. For me (my old tired eye?) that extra FOV just put new light into the target and it was quite nice.

 

 

Peace...


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#13 Lt 26

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Posted 16 April 2019 - 06:29 AM

Ethos. It is smaller and weighs less. It is already a 2" eyepiece and you don't need to add the bulk of an adapter. Anything over 1/2 pound I use in 2" format.

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#14 Sarkikos

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Posted 16 April 2019 - 09:19 AM

Define "immersive."  I think too often on amateur astronomy blogs it means something like, "the eyepiece had a wide apparent field of view and I liked it," with an emphasis on "I liked it."  

 

According to the Cambridge Dictionary, immersive means "seeming to surround the audience, player, etc. so that they feel completely involved in something."  

 

Given that definition when comparing two eyepieces, how could the one with a much wider apparent field of view, not be more immersive?  Why not just give the AFOV and be done with it?  shrug.gif

 

So, yes, of course, the Ethos would be more immersive than the Delos, more of a spacewalk.

 

Delos for planet/lunar, Ethos for deep sky.  Unless your mount doesn't track, then get an Ethos for planet/lunar as well as deep sky. 

 

I don't think the Delos are any sharper or more contrasty than the Ethos, but they are smaller, lighter and less expensive.  For really serious planet viewing, I put in the XO's.  Unless I don't feel like pushing the scope so much.

 

The Delos have 20mm eye relief vs 15mm in the Ethos. The comfort factor is about the same for both, unless you want to move your eye close to see those last few degrees of the outer field with direct vision in the Ethos.

 

Mike


Edited by Sarkikos, 16 April 2019 - 09:41 AM.


#15 csrlice12

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Posted 16 April 2019 - 09:34 AM

Actually, when I want to tear M13 apart, I use my dob with the 4.7 Ethos....its not a fuzzy ball, its full of stars!


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#16 Starman1

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Posted 16 April 2019 - 09:37 AM

It might be related to the exit pupil generated in my scope, but I also find the 8mm Ethos to have the most easily accessed exit pupil in the series.

You can just move around, and the image is still there.  Hard to describe well, but it is an easy eyepiece to use.


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#17 rkelley8493

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Posted 16 April 2019 - 09:41 AM

Define "immersive."  I think too often on amateur astronomy blogs it means something like, "the eyepiece had a wide apparent field of view and I liked it," with an emphasis on "I liked it."  

 

According to the Cambridge Dictionary, immersive means "seeming to surround the audience, player, etc. so that they feel completely involved in something."  

 

Given that definition when comparing two eyepieces, how could the one with a much wider apparent field of view, not be more immersive?  Why not just give the AFOV and be done with it?  shrug.gif

 

So, yes, of course, the Ethos would be more immersive than the Delos, more of a spacewalk.

 

Delos for planet/lunar, Ethos for deep sky.  Unless your mount doesn't track, then get an Ethos for planet/lunar as well as deep sky. 

 

I don't think the Delos are any sharper or more contrasty than the Ethos, but they are smaller, lighter and less expensive. 

 

The Delos have 20mm eye relief vs 15mm in the Ethos. The comfort factor is about the same for both, unless you want to move your eye close to see those last few degrees of the outer field with direct vision in the Ethos.

 

Mike

Lately I've noticed that eye-p's with long eye relief & large eye lens seem to have views popping right out of them giving the impression that you are among the stars. 72is large enough, for me, that I have to slightly look for the field stop, while 100requires neck bending. So looking straight down the barrel, the full FOV is hardly taken in without searching for it. That's my experience though. The view is in the eye of the beholder**



#18 csrlice12

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Posted 16 April 2019 - 09:46 AM

The idea behind 100* eyepieces is its supposed to let the edges fade into the background, similar to normal vision.  I agree with Starman, there's just something about the 8 Ethos that just makes it comfortable to use...similar to the Pentax 


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#19 Sarkikos

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Posted 16 April 2019 - 09:49 AM

Lately I've noticed that eye-p's with long eye relief & large eye lens seem to have views popping right out of them giving the impression that you are among the stars. 72is large enough, for me, that I have to slightly look for the field stop, while 100requires neck bending. So looking straight down the barrel, the full FOV is hardly taken in without searching for it. That's my experience though. The view is in the eye of the beholder**

If you can't see the field stop, that should make the experience even more immersive!  grin.gif

 

Actually the disappearing field stop and the long eye relief were the major factors giving the 28mm Edmund RKE a space-walk effect.  The AFOV was only 45 degrees, but the eye relief was 25mm and the field stop was invisible while viewing through the eyepiece at night. 

 

Mike


Edited by Sarkikos, 16 April 2019 - 09:50 AM.

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#20 rkelley8493

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Posted 16 April 2019 - 09:52 AM

Actually, when I want to tear M13 apart, I use my dob with the 4.7 Ethos....its not a fuzzy ball, its full of stars!

When I want to "tear apart" M3 [love those choice of words lol.gif], the 5mm XW & 3.5 Delos is what I reach for [using a refractor]. When I first looked at M3, I forget what eye-p I was using, it just looked like a gray cloud in the shape of a ball. Enter the XW & Delos... and I saw individual stars packed in the center and exploding outward like fireworks drool.gif


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#21 Procyon

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Posted 16 April 2019 - 10:19 AM

When I want to "tear apart" M3 [love those choice of words lol.gif], the 5mm XW & 3.5 Delos is what I reach for [using a refractor]. When I first looked at M3, I forget what eye-p I was using, it just looked like a gray cloud in the shape of a ball. Enter the XW & Delos... and I saw individual stars packed in the center and exploding outward like fireworks drool.gif

You don't want the turkey legged 6mm Delos? grin.gif laugh.gif

 

PS> I see it in your sig actually, nice collection. How are you finding the 21mm Ethos eye placement so far? Just curious.


Edited by Procyon, 16 April 2019 - 10:21 AM.

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#22 rkelley8493

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Posted 16 April 2019 - 11:34 AM

You don't want the turkey legged 6mm Delos? grin.gif laugh.gif

 

PS> I see it in your sig actually, nice collection. How are you finding the 21mm Ethos eye placement so far? Just curious.

Haha I recently picked up the 6mm Delos on the classifieds, but it's still on the way. Eye placement on the 21 Ethos is great! Much easier to use than the Explore Sci 20mm 100o in terms of eye relief, light scatter, and color. It's one of those "How did they do that scratchhead2.gif ?" eye-p's. It's really close in magnification with the 22mm Nagler, but there ain't no way I'm trading or selling that! It serves as my finder piece for the most part, but choosing between the two would be kinda like choosing which child you love more lol.gif. I'm still having seller's remorse over the Pentax 10mm XW bangbang.gif . I sold it to get the 10mm Delos. Won't make that mistake again!


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#23 Lt 26

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Posted 16 April 2019 - 01:57 PM

The 6&8 ethos vs the 6&8 delos. The ethos are more compact, shorter and lighter. Especially when you put the delos in 2" mode.

I would rather move my head a little as opposed to panning the scope. The 6&8 delos baffle me.

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#24 Sarkikos

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Posted 16 April 2019 - 02:19 PM

The 6&8 ethos vs the 6&8 delos. The ethos are more compact, shorter and lighter. Especially when you put the delos in 2" mode.

The only Delos I've owned are the 6 and 4.5.  I own the 3.7, 4.7, 6, 8, 10, 13, and 21 Ethos.  For some reason I had the impression that the Ethos were larger and heavier. 

 

So I went to the horse's mouth - the Tele Vue website - for the true specs:

 

http://www.televue.c...=214&plain=TRUE

 

Delos 6:  16 oz, 4.1" from top of eyepiece to shoulder

Ethos 6: 15.5 oz, 3.5"

 

Delos 8:  16 oz, 3.6"

Ethos 8:  15.2 oz, 3.3"

 

Looks like a photo finish to me.   

 

grin.gif

Mike


Edited by Sarkikos, 16 April 2019 - 02:21 PM.

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#25 Piero DP

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Posted 16 April 2019 - 03:03 PM

I had both the 8mm and 12mm Delos and they were fine eyepieces. Never tried an ethos but I now own a Lunt HDC.

Needless to say that a 100 Deg ep offers a very different view from a 72 Deg one.

I feel you will be happy with both, but if it is the large fov that you long for, then you already know the answer.

In your position, I would get one in the second hand market, so that if you later decide that it isn't for you, you can simply sell it without much or any loss.

It's a personal decision really. Lots of people love ultra wide views. Personally, I prefer 70-80 Deg AFOV eyepieces as my eye finds these easier to observe through - not seeing the field stop makes me feel like I am missing something.

Edited by Piero DP, 16 April 2019 - 03:04 PM.

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