21mm Ethos v 35mm Panoptic

[Sarah]

A couple of months ago I posted about using the 21mm Ethos in our f/4.4 dob.

http://stargazerslou...-pupil-matters/

The exit pupil on the 35mm Panoptic was too high in an f/4.4 scope and we were losing quite a bit of contrast and detail.

Sunday night we were finally able to use these two eyepieces in a refractor. We used our ED100, so at f/9 the exit pupil on the Panoptic wasn't an issue. We therefore expected these eyepieces to perform very similarly.

We looked through both eyepieces on a few objects including M45, M42 and the Double Cluster. The Panoptic provides a slightly wider field of view than the 21mm Ethos, but it is only marginally wider. The views through the Panoptic were very nice, as expected. But with the 21mm Ethos, the views were better. The improvement was greater than expected. The views were brighter, sharper and more detail could be seen. They were generally much 'punchier' through the Ethos. With M42 the Trapezium jumped out in the Ethos and both Luke and myself could see an arc of nebulosity which was lacking in the Panoptic. No doubt the increased magnification helped with the improvement in these views.

We also both found the Ethos more comfortable to view through than the Panoptic.

After swapping the eyepieces over a few times, we decided there really was no contest and just continued observing with the 21mm Ethos. The Ethos weighs 2.25lbs compared to the Panoptic at 1.6lbs. Because of the increased weight of the Ethos we had considered whether we should keep the Panoptic to use in smaller scopes. Whilst the Panoptic is very nice, the Ethos is just better! Of course the main cons of the Ethos are the weight and the price!

[ollypenrice]

Sounds right to me. And once you get into situations where the exit pupil of the 35 Panoptic gets to be excessive (as in our 20 inch F4.1 Dob) then going to a wider FOV eyepiece with a shorter focal length becomes even more compelling.

The price of the Ethos will always draw flak. So be it. Pah, they can't be worth it! Oh yes they can. These are utterly astounding eyepieces and if I were made of money then I'd just buy them. I tried one of the first when Linton Guise popped one in our Dob and I was converted in a nanosecond. As for Jupiter in the TEC140 and TWO Ethi in a binoviewer... well, it should be illegal...

I really like your review, both rigorous and human. That's how to do it.

Olly

[crashtestdummy]

it is a lot of money but if you can afford it then why not?ive always wondered if the 30mm nagler is £300 better than the ES 82 30mm but you pay your money and take your chance.when i get my next scope which will either be an F4 or F3.6 i will likely put money asside to upgrading if my ES 82's arent't up to the job.

ive often wondered how the 100 degree ep's would do against a widefield 30mm+ so nice to get some feedback

[John]

The Ethos do deliver some improvements over the Nagler equivalents so perhaps it's not surprising that they do the same compared with the Panoptics. It is difficult comparing eyepieces of differing focal lengths though.

Everybody talks about the massive field of view and, price to match, with the Ethos range but their other characteristics are really in the top drawer too and well worth highlighting, as you have, Sarah

[Sarah]

I agree with John that it is very difficult to compare different focal lengths. The main reason for comparing these two is that they provide a similar true field of view of around 1.2 degrees in our 16" dob. In the ED100 the true field of view is 2.5 degrees with the Panoptic and 2.3 degrees with the Ethos.

When we moved from a 12" to 16" dob, we were disappointed to see the views in the 35mm Panoptic worsened rather than improved, despite the extra aperture. We soon quickly realised this was down to the increased exit pupil. The Ethos remedied that and is quickly becoming one of our most used eyepieces in the dob. For me, it is worth the cost, just for the difference it makes when used with a fast dob.

I did expect a slight improvement with the Ethos in the refractor, but was surprised that the margin of improvement was greater than expected. So much so that it is now making it hard to justify keeping the Panoptic.

[John]

The problem is, once you have seen and enjoyed the difference, it's hard to be satisfied with your previous choice again

[Moonshane]

great review. the danger with this sort of thing is that you start thinking e.g. I have a 26mm Nagler (71x and 1.1 TFOV, 5.8mm exit pupil) and a 13mm Ethos (142x 0.7 TFOV and exit pupil 2.9mm) for use in the 16" f4 dob (f4.5 with Paracorr). if I sold both of them I could buy a used 21mm Ethos (88x 1.1 TFOV and 4.7mm exit pupil) which would almost cover the same sort of ground (and maybe start saving for a 12mm T4........).

[crashtestdummy]

probably wasnt a danger before your great explanation shane

[andrew63]

What puzzles me, in the debate for the wider higher power over lower to give the same field but with greater contrast, is fine for certain circumstances, like to high an exit pupil - but a 21 ethos in say a 100 f9 = 43x you would still require a lens to give a low power mag in the say 25x range for certain objets - so ideal for the 35 pan - i would have thought that you would really need both as they do 'different' jobs. The view must be fantastic though...

andrew

[Luke]

I thought Sarah was crazy when she said she wanted to try the 21mm Ethos on the 100mm.

It's such a heavy eyepiece and we were using a giro mount where you have to be a bit careful with balance. I didn't think there would be much in it in an F9 scope, so we might as well use the lighter 35mm Panoptic.

The missus was right (unfortunately, this is a running theme...), and on the four targets we looked at (M81 and M82 also), the view was better in the Ethos.

I guess you would hope so given the price, but for us it was more about getting it for our F4.4 dob, where we had a frustrating problem with the large exit pupil on the 35 Panoptic making it look washed out. The Ethos gives us about the same field of view as the 35 Pan in our dob and looks punchy.

I'm surprised at how good it was in the ED100, how comfy it feels to use, how it can show details sometimes that I can't see in other very good eyepieces, and how much easier I find to take in the 100 degrees than I thought I would. I was expecting to have to swivel my eyeball around, which I would soon get tired of, but it's fine for me.

[Sarah]

1359497619[/url'>' post='1806573']

The problem is, once you have seen and enjoyed the difference, it's hard to be satisfied with your previous choice again

Very true John!

1359497648[/url'>' post='1806577']

great review. the danger with this sort of thing is that you start thinking e.g. I have a 26mm Nagler (71x and 1.1 TFOV, 5.8mm exit pupil) and a 13mm Ethos (142x 0.7 TFOV and exit pupil 2.9mm) for use in the 16" f4 dob (f4.5 with Paracorr). if I sold both of them I could buy a used 21mm Ethos (88x 1.1 TFOV and 4.7mm exit pupil) which would almost cover the same sort of ground (and maybe start saving for a 12mm T4........).

Go on Shane, you know you want to!

I would think the 26mm Nagler and 21mm Ethos head to head would be a closer contested battle. We did consider the Nagler, but as I really don't get on with the T6 Naglers (blackouts and kidney beaning) I didn't want to take a chance on another type of Nagler.

[alan potts]

Nice review sarah, I may just get one of these. If I did not have the 20mm Nagler I am sure I would already be 700 quid worst off.

Alan.

[ollypenrice]

You really do have to watch that exit pupil in the big Newts. Going from 35 Pan to 26 Nagler in ours was like adding six inches to the mirror. I can't 'back to back ' them because the Panoptic was killed in action (half-snagged compression ring while someone was taking it out on the zenith, which is why I hate those things). But the Nagler 26 in the TEC 140 is beautiful beyond belief. The Pleiades... aaahhh.

Olly

[Moonshane]

when I get my 12" f4 up and running, I am looking forward to seeing Pleiades in the 26mm Nagler.

[Damo636]

Nice review Sarah! I would agree with everything you have said about the 21 Ethos, its a wonderful eyepiece. I use this eyepiece more than any other in my small collection. At 71x 1.4° in my 12" dob, its enough power to bring most objects to life and still provide enough fov to frame all but a handful of the larger targets. The first time I viewed M42 with it, my jaw almost hit the floor! It was almost as if I was within the nebula! This eyepiece creates a feeling of total immersion that no other ep I have owned can compare with! IME, its also the most comfortable of the Ethos line to use, followed closely by the 13mm.

[Mark at Beaufort]

Hello Sarah/Luke hope you are both keeping well.

An interesting and maybe an expensive thread for me. Ever since the 21mm Ethos came on the scene I thought about selling my 20mm and 26mm Nagler EPs to fund it. I put off the decision thinking I would not gain much but I now have doubts again and only 2 weeks before Astrofest.

Hopefully will see you both in March at Lucksall.

Mark

[John]

...An interesting and maybe an expensive thread for me. Ever since the 21mm Ethos came on the scene I thought about selling my 20mm and 26mm Nagler EPs to fund it. I put off the decision thinking I would not gain much but I now have doubts again and only 2 weeks before Astrofest.....

I'm feeling the same Mark. I'd have to let the 20mm and the 31mm Nagler go though and I'm wondering if I'd miss the 31 in due course ?.

Telescope House seem to be sold out of the Ethos 21 at the moment.

[Sarah]

1359499471[/url'>' post='1806632']

What puzzles me, in the debate for the wider higher power over lower to give the same field but with greater contrast, is fine for certain circumstances, like to high an exit pupil - but a 21 ethos in say a 100 f9 = 43x you would still require a lens to give a low power mag in the say 25x range for certain objets - so ideal for the 35 pan - i would have thought that you would really need both as they do 'different' jobs. The view must be fantastic though...

andrew

For me, the idea of using something like the 35mm Panoptic is to get a wider field of view, to squeeze in as much as possible of a larger object, or even to just to put a smaller object in a nice wide field frame, or maybe to frame more than one object together. In the dob, because of the exit pupil issue with the Panoptic, the 21mm Ethos makes sense.

Yes the Panoptic gives a slightly wider true field of view than the Ethos, in the 100ED, and it could therefore be argued that this is a reason to keep the Panoptic. But, for me at least, the difference in the true field of view between the two eyepieces is minimal. So if the objects look brighter, sharper and more detail can be seen, in a very similar field of view with the 21mm Ethos, I personally can see little reason to keep using the Panoptic, which is a shame as it is a lovely eyepiece.

I appreciate that objects can look better at varying magnifications, as we do swap eyepieces over to see if more or less magnification improves the views. But for me a widefield eyepiece is about that, a wide field, and the actual magnification provided is much less relevant than the true field of view. Here I am comparing a 68 degrees apparent field of view eyepiece with a 100 degrees one, mainly because this is about as wide as we can go with the true field of view (at least in our dob). If you are looking at two eyepieces that were say both 68 degrees then I could see the benefit to having something like a 21mm and 35mm eyepiece.

This of course is my personal view and I​ may be missing an obvious point here, so please feel free to correct me!

Yes the views are fantastic. Although it was a bit scary spending so much on one eyepiece!

[Sarah]

1359539522[/url'>' post='1806919']

Hello Sarah/Luke hope you are both keeping well.

An interesting and maybe an expensive thread for me. Ever since the 21mm Ethos came on the scene I thought about selling my 20mm and 26mm Nagler EPs to fund it. I put off the decision thinking I would not gain much but I now have doubts again and only 2 weeks before Astrofest.

Hopefully will see you both in March at Lucksall.

Mark

Yes thanks Mark, we are well. Hope you are keeping well too.

Having not used Naglers in the longer focal lengths, I am uncertain as to how much of a benefit you would or wouldn't gain if you switched to a 21mm Ethos. I wouldn't want to be responsible for you weakening and buying the Ethos! You have two weeks to build up your resistance before Astrofest!

We are looking forward to trying the new dob under darker skies at SGL 8. It will be nice to see you there Mark.

[andrew63]

For me, the idea of using something like the 35mm Panoptic is to get a wider field of view, to squeeze in as much as possible of a larger object, or even to just to put a smaller object in a nice wide field frame, or maybe to frame more than one object together. In the dob, because of the exit pupil issue with the Panoptic, the 21mm Ethos makes sense.

Yes the Panoptic gives a slightly wider true field of view than the Ethos, in the 100ED, and it could therefore be argued that this is a reason to keep the Panoptic. But, for me at least, the difference in the true field of view between the two eyepieces is minimal. So if the objects look brighter, sharper and more detail can be seen, in a very similar field of view with the 21mm Ethos, I personally can see little reason to keep using the Panoptic, which is a shame as it is a lovely eyepiece.

I appreciate that objects can look better at varying magnifications, as we do swap eyepieces over to see if more or less magnification improves the views. But for me a widefield eyepiece is about that, a wide field, and the actual magnification provided is much less relevant than the true field of view. Here I am comparing a 68 degrees apparent field of view eyepiece with a 100 degrees one, mainly because this is about as wide as we can go with the true field of view (at least in our dob). If you are looking at two eyepieces that were say both 68 degrees then I could see the benefit to having something like a 21mm and 35mm eyepiece.

This of course is my personal view and I​ may be missing an obvious point here, so please feel free to correct me!

Yes the views are fantastic. Although it was a bit scary spending so much on one eyepiece!

Yes what you say makes a lot of sense Sarah - but what i find - if you 'ignore' how wide the field of view is. An object like M101 or low surface brightness objects in general, can require less mag. to stand out more against the background sky and throwing more power to darken the sky, can spread the object out too much and become harder to observe - certainly in a smaller telescope.

[Sarah]

Yes what you say makes a lot of sense Sarah - but what i find - if you 'ignore' how wide the field of view is. An object like M101 or low surface brightness objects in general, can require less mag. to stand out more against the background sky and throwing more power to darken the sky, can spread the object out too much and become harder to observe - certainly in a smaller telescope.

Thanks for your reply Andrew. That is something I hadn't considered and would be interested in testing.

[John]

I've generally found that a little more magnification makes faint objects just that little bit more distinct against the background sky, from my moderately light polluted back garden anyway. Thats why my 20mm Nagler is more used at home than my 31mm. And also why the 21mm Ethos may well be a good solution

[Sarah]

I've generally found that a little more magnification makes faint objects just that little bit more distinct against the background sky, from my moderately light polluted back garden anyway.

Thanks for your input John. I am hoping we can have another look tonight.

Thats why my 20mm Nagler is more used at home than my 31mm. And also why the 21mm Ethos may well be a good solution

Sounds like you are convincing yourself the 21mm Ethos is needed! TS have them in stock.

[andrew63]

I guess it's a fine balance - between darkening the sky and not loosing contrast in the object. When looking at notes on M101 it was fine in a 26mm but becoming more indistinct in a 16mm - i'm thinking the extra contrast was negated by the objects light being more thinly spread out - but this is of course is in a small aperture telescope. Not a problem for you guys with mirrors like lighthouses!

andrew