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Terminagler Incoming!!

Damo636

By Damo636
in Discussions - Eyepieces

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  • 3 weeks later...
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Damo636

Damo636

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Ok Russell, you asked for it :-)

Update time!

I have been using and comparing these three big eyepieces now for over a month, and have arrived at a few conclusions!

First up, the 21mm Ethos!

This is without doubt, the finest low power, ultra widefield eyepiece I have used to date. The views I have had through this eyepiece have been nothing short of breathtaking!

The 21mm Ethos replaced a 26mm Nagler, itself a wonderful eyepiece that I couldn't fault. Although on paper, both eyepieces produce an almost identical tfov, in practice the Ethos feels larger. The feeling of being totally immersed in the view is second to none with this eyepiece. Sharpness, throughput and contrast are simply stunning. Star colours really stand out against the black background sky and it is definitely capable of going deeper than either the 31mm Nagler or 30mm ES. The double cluster has to be seen to be believed, simply jaw dropping! This has, without a shadow of a doubt, become my favourite eyepiece. I suppose the only negatives I could aim at it are that its heavy, exactly the same weight as the ES 30mm as it happens, and it cost almost as much as my scope!!

The 30mm ES/31mm Nagler comparison took me a bit longer to decide which I prefered. In all honesty, there is precious little between these ep's. To say one is better than the other would be unfair as both are excellent & both have their quirks.

I compared both these ep's on a variety of different targets on different nights. I found nothing visible in one that wasn't visible in the other so would conclude that light throughput was about equal. An earlier post suggested that the Nagler showed better contrast and control of scatter on bright objects. Personally, I could see very little difference, if any.

I stated earlier that the 31mm Nagler has a slightly larger tfov and ever so slightly better edge correction. After a lot of swapping back and forth later, I would now conclude that the tfov's are practically identical and the edge correction is indeed very slightly better with the Nagler. At the extreme edge of the fov, the stars are slightly sharper in the Nagler, but it really is in very outer field. I feel f5 & faster, may be the point where the ES may just start to lose a little ground on the Nagler, in terms of edge sharpness.

At f5, Coma, although no fault of the eyepiece, is of course evident in all these ep's and is the dominant abberation. So far though, at f5, I haven't felt the need for a coma corrector, although it probably would be a good idea not to look through a scope with one in place!!

CA is present in both ep's in the outer fov. This is most noticeable by letting the moon drift across the fov. From about 75-80% out from centre, it starts to appear in the ES as a green halo. The Nagler shows the same effect, but further out, and just not as distracting. To be honest though, I've only seen this abberation while viewing the moon, so I wouldn't count it as a deal breaker.

I have read many times where some 31mm Nagler users have felt a little motion sickness while panning around the sky. I think its down to the amount of pincussion distortion built into the design of the eyepiece, a trade off for extra edge correction. When slewing the scope through a star field, its almost as if space is bending! I hadn't really noticed it in any other eyepiece I've used, & the effect is quite pronounced with the Nagler, especially when the scope is slewed quickly. To be honest though, it doesn't bother me in the slightest as I wouldn't normally be slewing about like that anyway. The ES 30mm definitely has the flatter field. I suppose for some this could be a deal breaker, as the last thing anyone wants is to start feeling motion sickness while observing!

Another thing I found was the eye placement was slightly more comfortable with the Nagler. The eye lens is recessed approx 8mm in the ES, and even though the eye relief is quoted at 21mm, I found I had to have my eye socket almost resting on the eyepiece to comfortably see the entire fov. Even though the Nagler has 2mm less eye relief, I found it slightly easier to use. This is purely subjective though and probably nit picking if I'm honest!

So, bottom line...

I am far from being the most experienced observer, and a more seasoned astronomer may see it differently, but....

In my humble opinion....

Either of these two excellent eyepieces will serve their purpose equally well & I honestly would be just as happy to own either. As it turns out, I am keeping the 31mm Nagler & a mate has took the ES. It saves me sending it back to the US for a replacement, (defective filter thread) and he's happy to have aquired an excellent eyepiece at much reduced price!

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John

John

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Very good report Damo :smiley:

The differences between the ES30 and the N31 sound similar to those I found between the N31 and the Nirvana 28mm, ie: very slight and as much about ergonomics as anything else !

I guess the value for money vote would have to go to the ES30 wouldn't it ?

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alan potts

alan potts

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Damo,

Very nice report and as it happens very much the same sort of report that was written when Meade 30mm UWA and 31mm Nagler were put head to head some years back. I remember saying was it possible to get a Meade in the mix. My belief is you had one there anyway in different clothing. At this level there is never going to be a great deal of difference.

However on the back of what you said i may just get a 21mm Ethos.

Alan.

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JamesF

JamesF

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Here's my 27mm Pan with the 5mm BGO. Bear in mind that the Pan would easily hide behind the can of beans :)

Reminds me of a certain 70s comedy duo (I use the word "comedy" in a fairly loose sense there). One of whom now lives pretty close to John, I believe.

pan-bgo.jpg

James

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John

John

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.....Reminds me of a certain 70s comedy duo (I use the word "comedy" in a fairly loose sense there). One of whom now lives pretty close to John, I believe.......

Yes indeed, Eddie is a local. Along with Carol Vorderman, thats about it around here though !

On big eyepieces, Naglers used to be a lot bigger of course :grin:

post-118-0-25663200-1348870730_thumb.gif

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estwing

estwing

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In our house it is the tin of beans that would be the rarest thing. I will now do a review of the beans versus the 13mm Ethos with the bottom lens cap left in place, beans are a clear winner when toast is in the mix

Alan.

....would this be a...T.V. dinner! :lol:
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