Low magnification options

[Moonshane]

I use my 26mm Nagler an awful lot and it's a superb eyepiece, I forget how good it is to be honest until someone looks through it for the first time. I have had a 24mm Panoptic and a 22mm Panoptic and both were superb but definitely a different feel. I actually really like the 68 degree field despite not having an eyepiece with such a field at the moment. I'd expect the 27mm to be excellent and my choice was between the 27P, the 22N and the 26N vs my 35P (too big an exit pupil with my LP and f4 scope) and based on field of view I went for the 26N. I have never regretted it.

The Ethos as good as they are (I have the 13mm) are not something I would buy any more of as I like to see the field stop. I like the 13mm and have often toyed with the idea of selling it to fund a 12mm T4 plus cash or something else, but can never bring myself to do it. For this reason I would not go for the 21E.

[Stargazer_00]

A good, well made argument.  Thanks Shane.  I will continue to ponder on it.  The good news is the stars arent going anywhere and I really have no reason to rush this choice.   And even then, if I pick something up second hand I can always sell it off and get something else anyway.    Maybe that's the real solution, buy whatever comes up on the list second hand first and if it doesn't satisfy, sell it on for little or no loss and wait for the next thing to turn up.

[laowho]

Its an opinion and perfectly valid.  We don't challenge each other like this on SGL - everyone is welcome to their viewpoint, as are you of course   

It wasn't a challenge. It's a request for clarification. There are several factors that would play in personal observations and opinions, not the least of which would be the condition of the primary. People have the right to know where they might save money if they needed to. I fail to see how mischaracterizing my post helps anybody.

[laowho]

I've looked back over the original "challenge" to what I said, then my supporting evidence, then the following emphatic "challenge" from someone else, whereupon I asked for source material and for which I was chastised, both as a troublemaker and as an outsider. Message received. Best wishes everyone.

[Andy_E]

Iaowho, please don't feel you are being ganged up on as I'm certain that is not the intention of any of the above posts. I apologise if I have caused any upset, but like I said I simply feel that my experience differs from yours regarding the issue in hand. As far as I am concerned my own experience is evidence enough... if others have different experiences that's fine, and I'd encourage them to raise them so we can gather the whole picture.

Clear skies mate,

Andy

PS Graham; the S/H solution sounds like a great (and potentially fun) idea... done it a few times myself (only I'm rather guilty of not selling eyepieces on afterwards!)

[Dude_with_the_tube]

Graham,

if you can wait for a couple of weeks,i will be shortly getting exactly the same scope you have (skywatcher 350p) and as you can see i have completely changed my box of Ep`s.i sold all the BGO`s (regrettably) and I also sold the Meades UWA and got instead ES 9 and 20mm and by a share luck i snatched TV 13mm Ethos for a fantastic price,where original thought was to get the ES range 9;14 and 20. 

2 Ep`s are still with carriers and I expect them to be with me by end of this week,where the order for scope will be placed on monday coming.Then i can do a quick sort of first light to let you know how the 20mm performs in 14" dob.I have done a bit of research and been talking to Andrew and we came to conclusion that the 20mm ES should perform brilliantly.i did play around with the idea of having additional EP after the 20mm,but for time being i am not getting any as the FOV of 20mm is literally almost the same what 30mm 82 degree EP gives with only a few min difference so i gave up on it.Obviously if the 100 degrees are not what you are after,then ignore me mate.

P.S. i will be using a barlow to get the maximum range out so at the end i should be:4.5 (overkill maybe for 14") 6.5;9;10;13 and 20mm what should cover me perfectly.

[AlexB67]

Rather than stating about what coma does and doesn't quantitatively to the best of my understanding so far in terms of how it affects things through an eyepiece at a given magnification,  I could be wrong of course, but personally I'd say a lot of where this comes from is that at lower mag and much brighter stars, aberrations can become easier to see as they stand out. Try M45 and Orion Neb, ideal test beds.

[Stargazer_00]

Graham,

if you can wait for a couple of weeks,i will be shortly getting exactly the same scope you have (skywatcher 350p) and as you can see i have completely changed my box of Ep`s.i sold all the BGO`s (regrettably) and I also sold the Meades UWA and got instead ES 9 and 20mm and by a share luck i snatched TV 13mm Ethos for a fantastic price,where original thought was to get the ES range 9;14 and 20. 

2 Ep`s are still with carriers and I expect them to be with me by end of this week,where the order for scope will be placed on monday coming.Then i can do a quick sort of first light to let you know how the 20mm performs in 14" dob.I have done a bit of research and been talking to Andrew and we came to conclusion that the 20mm ES should perform brilliantly.i did play around with the idea of having additional EP after the 20mm,but for time being i am not getting any as the FOV of 20mm is literally almost the same what 30mm 82 degree EP gives with only a few min difference so i gave up on it.Obviously if the 100 degrees are not what you are after,then ignore me mate.

P.S. i will be using a barlow to get the maximum range out so at the end i should be:4.5 (overkill maybe for 14") 6.5;9;10;13 and 20mm what should cover me perfectly.

this is exactly what I'm after!  Someone with the same scope and the 13E to compare to the ES 20 100!  350p owners are few and far between so I suspect you and I are going to have much to share to help one another   If you want any advice on the eyepieces I currently have let me know and I'll give you a run down of the performance in the scope.

[Stargazer_00]

Rather than stating about what coma does and doesn't quantitatively to the best of my understanding so far in terms of how it affects things through an eyepiece at a given magnification,  I could be wrong of course, but personally I'd say a lot of where this comes from is that at lower mag and much brighter stars, aberrations can become easier to see as they stand out. Try M45 and Orion Neb, ideal test beds.

Hi alex,

It's my understanding that low magnification options use more of the light gathered by the objective.  As the field you see increases so the light that populates that part of the field is getting closer to the edge of the primary.  In the case of fast newts the edge light is fed from the edge of the mirror, which is the most tortured part of the light being reflected off of the mirror.  It is for this reason that the edge is worse at low magnifications.

That's my general understanding of the mechanics anyway.  Seems to make sense.

[Stargazer_00]

I've looked back over the original "challenge" to what I said, then my supporting evidence, then the following emphatic "challenge" from someone else, whereupon I asked for source material and for which I was chastised, both as a troublemaker and as an outsider. Message received. Best wishes everyone.

I've very upset that this thread led you to get upset.  As the OP for this thread I would like to thank you again for expressing your opinion and hope that you appreciate my gratitude in you taking the time to reply.  Thank you again.

[Dude_with_the_tube]

this is exactly the problem i had,there are only a hand full of 14" dob users here and not much info on how and what is happening.Even less info on the eye piece selection/performance.I had to dig through Cloudy Nights forums to get all the info i needed,had to do a few phone calls for advise but at the end,i think i did the right choice on Ep`s.Well,atliest i hope i did

i will keep you informed on everything,but you will have to hold on for another week until my scope turns up and i get kicked out of the house lol,unless someone takes my 10" dob.

[RikM]

Everyone is entitled to their opinion. 

You could argue that different eyepiece characteristics become more important as you move from higher to lower magnification. On axis sharpness, control of light scatter etc. take priority in high magnification viewing of small bright objects. I find as magnification decreases, you are seeing more of the image circle delivered by telescope. Things like coma and astigmatism are more pronounced. The important characteristics of eyepieces at this end of the scale are control of astigmatism, geometric distortion and important for me, contrast. I tend to use higher low magnification than some. 20mm is my normal max. I do have a 28mm but don't use this FL very often due to lack of contrast against my light polluted sky. I chose to save a few quid on this eyepiece (compared to my others) purely down to how often it will get used. It only gets 60% of the use, so I spent 60% as much. It isn't as good as the others. If I had darker a darker sky, I would probably have spent more.

[John]

I have the 13mm Ethos and the 20mm ES 100. The former is brilliant and the latter does very nicely indeed in my fastest scope which is the F/5.3 12" dob. At that focal ratio I could not justify the large additional investment to get a 21mm Ethos (they were over £700 new at that time) but I have a feeling that I would have stayed with my 20mm Nagler and saved the money for a 21mm Ethos if I had a scope faster than F/5. 

The ES 20mm / 100 is a great eyepiece and fantastic value but under F/5 things get really tough for eyepieces and I'm fussy about sharpness across the FoV. 

I'd have to have budgeted for a Parracorr as well of course !

[Mike73]

Have you tried ES in a fast scope John? 

I'm using the Baader MPCC mkIII with a ES 28mm 68˚ and I'm shocked by how good it is, if I had a choice between the 28mm + CC or my old 26mm Nagler I'd pick my 28mm + CC any day ( and I did love that Nagler!).

[John]

Have you tried ES in a fast scope John? 

I'm using the Baader MPCC mkIII with a ES 28mm 68˚ and I'm shocked by how good it is, if I had a choice between the 28mm + CC or my old 26mm Nagler I'd pick my 28mm + CC any day ( and I did love that Nagler!).

No - I'd moved on from my F/4.8 10" to the F/5.3 12" by the time I got the ED 20 / 100. Its very good at F/5.3 but not quite as good as the Ethos 13 right to the field edges so I'm assuming that faster would not help the ES 20's cause. At the time I bought the ES 20 / 100 I would have had to find over £300 more for a 21mm Ethos so I have no complaints about the big ES - it's just great in my scope 

[RikM]

Have you tried ES in a fast scope John? 

I'm using the Baader MPCC mkIII with a ES 28mm 68˚ and I'm shocked by how good it is, if I had a choice between the 28mm + CC or my old 26mm Nagler I'd pick my 28mm + CC any day ( and I did love that Nagler!).

That's good to hear. It's the ES 28mm 68° that I have and have been toying with adding a visual coma corrector.

[alan potts]

Of the Meade SWA's the 28mm (most likely the same thing) was my favourite, it also worked with the reducer on the LX where the 26mm Nagler does not without a bad vignette.

Alan

[Pig]

Graham,

I used the 31mm Nagler for quite some time last night and I can  honestly say it is a brilliant eyepiece everything fits in the FOV wonderfully

[Dude_with_the_tube]

i was thinking of the 31mm nagler but on 14" dob the exit pupil will be very close to 7mm (6,8)  what might cause problems.Correct me if i am wrong here.

[Stargazer_00]

I'd love a 31T5 but as Dude says the exit pupil is just way to big for my skies.    That's where the 21E comes in, it shows more or less the same true field over a wider apparent field and with a much better exit pupil (4.4ish if memory serves).

I've got a short list now and will wait patiently to see what comes up s/h.  I'll keep buying/flipping until I'm happy with the view or I end up with a 21E in my box at which point I can't fail to be happy

[crashtestdummy]

Ive used the ES 20 in an f4.5 with and without a paracorr and tbh its not a massive difference coma wise.you can see its there without the paracorr bit it doesnt detract from the viewing.i would sell my paracorr if i wasnt doing a 22" f3.6 as my next scope

[Stargazer_00]

I'll put an ES 20/100 on my shortlist and if one comes up s/h I'll take a punt on it too   I'm not brand loyal, only quality loyal.  If the quality of the view pleases me I then I'm satisfied.

[Dude_with_the_tube]

there are nice reviews on Cloudy nights for Es vs Ethos and to be fair,ES are so close in performance that it is a real struggle to justify that massive extra cost of TV.I am not loyal to any brand either,as soon as i can get the performance i want.the cost of 13mm Ethos or 14mm ES is not really miles away and you can always find a great bargain on either of them.I picked up my ethos for 285 quid posted.And that was the ONLY reason why i took it because 14mm ES worked out as around 200-250, completely different picture with 21mm Ethos.Yes I would love to have that green beast in my EP box and I perfectly understand that Mr Nagler is competing against a massive mass producer ,but it is double of the cost of ES and even second hand from US its still 700-800 USD +postage and our friends from customs,where ES is 300USD new or even less second hand.(not trying to open a can of worms here : TV vs the world)

[Stargazer_00]

I think my only concern with the ES was my experience with the 82 series in my fast scopes, I found them all wanting.

Is the 100 range a step change in performance both on axis and edge performance?

[scarp15]

this is exactly the problem i had,there are only a hand full of 14" dob users here and not much info on how and what is happening.Even less info on the eye piece selection/performance.I had to dig through Cloudy Nights forums to get all the info i needed,had to do a few phone calls for advise but at the end,i think i did the right choice on Ep`s.Well,atliest i hope i did

i will keep you informed on everything,but you will have to hold on for another week until my scope turns up and i get kicked out of the house lol,unless someone takes my 10" dob.

Fairly recently I have become a 14" dob user, although I take mine to dark locations, so no light pollution issues. The 27mm Panoptic would make for an excellent option, particularly if there is any light pollution. I used a 35mm Panoptic, which was great at dark locations. However I was also aware that perhaps due to the large exit pupil, with an F4,5 scope (and that I do not use a paracorr to reduce it to around 6mm) it was leaking some light, even under near pristine skies.

I considered the 31mm nagler some time back, but the same issue will occur (at F4.5 and faster)  in that the large exit pupil will not capitalise on the full light grasp potential of the scope. In my case I sold the 27mm and 35mmm panoptic's for a 26mm nagler (so far unused). so this too would be another feasible option.