FOV in 82 and 100 degree eyepieces

[Widefield]

I am starting to work out an upgrade path for my eyepieces to use in a 12" F4.9 dob and am looking at 82 and/or 100 degree eyepieces as the wider view appeals on paper at least.

However, I have a question I don't seem to be able to find an answer to anywhere. Is it actually possible to see all the FOV without moving your head around in say a Nagler or Ethos? I have heard some people say they can 'see the field stop' (while others cannot), but its not clear to me if this means they can look at the center of the FOV and be just about aware of the field stop on the edge of their vision without moving their head, or if they can actually only see the field stop by moving (as the diameter of the eye lens may not be wide enough to actually give access to the full 82 degrees without your eye being so close to the lens that you get kidney beaning etc). If the later is the case then does the eye lens then not introduce a restriction on the 'spacewalk' feeling to some extent?

What have people's experiences been?

[Naemeth]

I would hazard a guess that, at least with 100 or 110 degrees, that your eye can't take in all the view in one, you would probably need to move you eyeball slightly in order to see the edge. This, I think, is the point of the "space-walk" effect, if you can't see the edges of the field of view you psychologically feel there aren't any.

[estwing]

I have to move my head to try and "see" round the corner with my ethos..just like lookin out of a window of a rocket...with cat and rimmer in tow!

[John]

When I use my 82 and 100 degree eyepieces I don't really want to see the edges of the field of view. The appeal of them for me is to achieve the impression of an "endless sea of stars" with my target objects against that backdrop

If you prefer seeing your views framed with a black rim then I'd go for 70 degree or narrower eyepieces. Not everyone likes the ultra and hyper wide approach which is fine. Personally, I really do though

[Moonshane]

I am finding increasingly that I like both the narrower field of orthos and plossl as well as the wider field of Nagler and Ethos. what I use depends on what I am viewing. with bright planets, the moon and double stars I much prefer to see the field stop and with such objects, a wide field is not important. particularly for the moon I really don't like Nagler/Ethos but think I am almost alone here.

for star clusters, galaxies and nebulae I really like to see the object in context with the background so a wider field is preferred. whether or not you can see the whole field depends on what you are viewing and the eyepiece used. I have a 26mm Nagler and the field is readily seen as it would be I expect with a 31mm Nagler, possibly a 20mm Nagler and the T4 Naglers as they have long eye relief.

with an Ethos (I have a 13mm), you have both a shorter eye relief and a wider field so the field stop is not easy to see but if you look at the centre of the field, it is visible with averted vision. broadly, this latter method will work for all wide field eyepieces and although you have to work to see the whole field if you look directly, at the centre and with averted vision you do get the 'spacewalk' feeling as described.

Personally I always found the Panoptic 68 degree field the most comfortable but the Ethos and Naglers are very impressive.

[Widefield]

Thanks for the feedback. I certainly buy into the idea of not seeing (or being aware of) the edges giving a feeling of being out there. But on the other hand I worry that paying premium prices for the wider FoV and then not being able to take it all in easily could come back to annoy me in the future.

I think the ony way out of this is to 'try before you buy' and see how I get on with them - even though I soooo want to just go ahead and spend the money I dont have now! I have been lucky enough today to get a loan of an ES 14 100 and an ES 11 82 from a old friend to see how I get on - should have them in the next few days. Only problem is I can see me liking them AND something around 70 degrees where its 'all there in front of you' and ending up with duplicate sets of Ethos and Panoptics/Delos in place of the house and wife I currently have!

Ah well, if it was straight forward it probably would'nt be as much fun

[John]

Borrowing them to see for yourself is very sensible

It's quite correctly said on here frequently that eyepiece choice is a highly personal thing and what floats one persons boat might not be at all enjoyable by another.

The only thing I'd add is to give yourself some time before jumping to a conclusion. Ultra and Hyper wide eyepieces can take some getting used to and sometimes a slightly different approach to eye and even head positioning is needed to get the best from them. So have a few sessions with them, if you can, and view a variety of different object types, before making your mind up.

[bingevader]

what I use depends on what I am viewing. with bright planets, the moon and double stars I much prefer to see the field stop and with such objects, a wide field is not important.

For star clusters, galaxies and nebulae I really like to see the object in context with the background so a wider field is preferred.

Although on a much more limited scale (both in EPs and experience), I'd have to say the same!

Is the planets in narrower EPs akin to the moon illusion? You're framing it in much smaller EP and so it has the illusion of appearing bigger rather than getting lost in the surrounding stars?

Cheers

[Moonshane]

I think you may be right. sometimes I try out switching from my 12.5mm BGO to my 13mm Ethos and the planet will look tiny in the Ethos even though magnification is pretty close. it appears to be an illusion but I like it.

[John]

This was the argument deployed when TMB bought out the Supermonocentric eyepieces. The 30 degree apparent field of view would ensure that the observer concentrated on the target. Maybe thats taking it too far though !

[alan potts]

Forgive me for sounding like we are brothers or something but my affair with the 100 degrees FOV is very much in line with what John states, I don't even try to see the edges, I can but for me thats not the reason I have them, it is for that lost in space feeling ( wonder what happen ed to that series). However on the the 82 degree FOV I do tend to look at the edges because they are much closer, 18 is not a very big number but it is when put it on a FOV. If you want to see the edges and have your eye take in all the view and have it framed you should stick to the 68 degree SWA or Panoptic FOV.

But to answer your question Yes I can see the edges but by moving my eye, not head.

Excellent advice from Moonshane as well, this is very true!

Alan.

[Widefield]

Thanks everyone. I will give them a good go and see how I get on.

[John]

....Forgive me for sounding like we are brothers or something but my affair with the 100 degrees FOV is very much in line with what John states......

Actually my brother is called Alan and he does look a little like you

He is usually to be found in Norway though, rather than Bulgaria.

[Stargazer_00]

personally I can see all the field in 82 degrees of looking at the centre. direct vision of the field stop though requires significant head movement. I would expect 100 degrees to not show all the field stop even with averted vision when looking into them directly. certainly I looked into an es 120 and saw nothing but field. I share shanes point of view in that this is great for dso but solar system typically work better in narrower field of view. I'm going to add a few delos to my line up next after scope upgrade and then probably a few panoptics. I don't think I'll get anything smaller than 68 but we will see.

[rwilkey]

Thanks for the feedback. I certainly buy into the idea of not seeing (or being aware of) the edges giving a feeling of being out there. But on the other hand I worry that paying premium prices for the wider FoV and then not being able to take it all in easily could come back to annoy me in the future.

I think the ony way out of this is to 'try before you buy' and see how I get on with them - even though I soooo want to just go ahead and spend the money I dont have now! I have been lucky enough today to get a loan of an ES 14 100 and an ES 11 82 from a old friend to see how I get on - should have them in the next few days. Only problem is I can see me liking them AND something around 70 degrees where its 'all there in front of you' and ending up with duplicate sets of Ethos and Panoptics/Delos in place of the house and wife I currently have!

Ah well, if it was straight forward it probably would'nt be as much fun

I have the ES82 14mm and 11mm and love the views, yes, you could move your eyeball around but I tend not to. I find you need to get your eye quite close to the eyepiece to appreciate the view, which came as a bit of a surprise to me when I first used them as I understood the eye relief was better, but probably over-stated as with many manufacturers, but I find them very good and a great experience. With my C100ED the 11mm gives me a 1 degree FoV. Great!

[John]

ES countersink their eye lenses a few mm below the physical top of the eyepiece Robin which robs the user of a little of the published eye relief. Eye lenses tend to be concave in these ultra-wides too and eye relief is measured from the centre of the lens of course. I reckon these factors can reduce the usable eye relief by as much as 5mm.

[Moonshane]

the Ethos often feels like a lot less than 15mm also for the same reason. It's just getting used to how to use these wide fields I think - there's definitely a knack and perhaps is another reason for the marmite effect.

[scarp15]

Personally I always found the Panoptic 68 degree field the most comfortable but the Ethos and Naglers are very impressive.

Panoptics, at low power i.e. 35mm, 27mm are worth considering for their very forgiving eye relief and good wide field, which as Shane has mentioned, is comfortable to view.

[Widefield]

I got hold of the loaner ES 11 82 and 14 100 late yesterday. I have read about the size of the 100 degree eyepieces but my word it is HUGE - more like a 200mm amera lens than an eyepiece!

I spent quite a while just looking through them (no scope) to get a feeling for the eye position, FoV, comfort etc. At first it was very irritating as I could'nt help myself trying to look directly at the field stop, and thats not easy to do. This morning however I relaxed and spent some time just looking at the centre and doing that you can just (am I mean only just) sense there is an edge out there somewhere with the 82 without moving and with just a little movement in the 100. That seems perfect - the field is not being wasted but you are not boxed in.

With the 14 100 in particular it was a very nice experience. The large eye lens makes the whole experience very relaxing and immersive. The 11 82 has a smaller eye lens so it felt perhaps a little less 'expansive', but still very nice - I agree about the eye relief on the 82 as well - it seemed tighter than advertised if you want to see the whole FoV. Just from that quick look see I think it has answered my initial question and I get the point of the concept now in theory at least.

Now I just need to get a break in the clouds and I can try them out for real and see how I get on. First impressions are though that this could turn out to be expensive, although I am hoping the ES versions will hold up in my f4.92 scope so I don't have the venture down the black and green path!

[Moonshane]

in a nutshell, that's exactly how I use the wide field. relax and look at the centre and you naturally get it all. struggle or look to the side where the field stop is and you cannot see it. like an atomic particle in a way - look at it and it's no longer where it should be!

[jabberwocky]

I love the view through an ethos, just watching stars drift through the view is lovely, then something catches your eye as it drifts into your peripheral vision, just turn your head and look almost along the plane of the lens and there it is in direct vision, just as crisp and clear as if you had centred it in the ep. You can then watch it all the way across the ep. On a dob mount wide eps are hard to beat.