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Walking on the Moon

Cost vs visual differences


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How good is the TV Nagler? I mean really? I had the privilege of looking through one recently and on reflection I think the occasion may have got to me. I'm pretty sure that I could have been looking through a much, much cheaper eyepiece and still felt the quality pouring into my eye, so ready was I for my mind to be blown! 

Now thinking about this, and even though the quality of that eyepiece is undoubtedly good great, I'm wondering how the complete experience of using a top brand eyepiece compares to products in different tiers of the price/quality pyramid. As well, I understand that these were developed by Al Nagler in the 60's and apart from some minor material changes, they remain much the same and have only improved upon in regards to AFOV (by the Ethos range). To me that says that they're quite a simple product and therefore shouldn't be that difficult to copy or cut the cost of (from a competition point of view this is).  So this kind of descends into a hybrid of a bang for buck and diminishing returns topic I suppose. But I'm genuinely interested to know your thoughts on it. Essentially the question is are we overpaying for a great product and where on the spectrum does the quality start to tail off?

Also I'm not aware of any available resources that present standardised eyepiece performance information. Are there any?

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I have to say I was expecting the second coming when I bought my first TV eyepieces, mostly Radian and Plossls but I also had a couple of Nagler’s. I wouldn’t say I was disappointed, but wasn’t wowed out either. It’s just an eyepiece at the end of the day isn’t it. I wouldn’t buy anything new TV wise, but there are some great bargains second hand 

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I've had a few Naglers - T4 22mm and 17mm, T6 7mm. They are good, very good. But I'm more than happy with my Nirvanas at a quarter of the cost :smile: 
I swapped the 22mm and 17mm for the equivalent LVWs. Not as wide, or as heavy, but more comfortable to use.

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30 minutes ago, NotSoSuperNova said:

Also I'm not aware of any available resources that present standardised eyepiece performance information. Are there any?

Some of the topics by Louis D are very good reading. Some great info on eyepiece characteristics in a variety of scopes and different focal lengths.

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26 minutes ago, Carl Au said:

I have to say I was expecting the second coming when I bought my first TV eyepieces, mostly Radian and Plossls but I also had a couple of Nagler’s. I wouldn’t say I was disappointed, but wasn’t wowed out either. It’s just an eyepiece at the end of the day isn’t it. I wouldn’t buy anything new TV wise, but there are some great bargains second hand 

This is what I was thinking might be the case if I went back and looked with a more critical eye. I'm certain I'd still be impressed but perhaps not wow'd. I think I'd have to get lucky even in the second hand market to bag any one of these. Fingers crossed though!

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26 minutes ago, Mr Spock said:

I've had a few Naglers - T4 22mm and 17mm, T6 7mm. They are good, very good. But I'm more than happy with my Nirvanas at a quarter of the cost :smile: 
I swapped the 22mm and 17mm for the equivalent LVWs. Not as wide, or as heavy, but more comfortable to use.

I thought it might be the case which is why I mentioned the performance testing. Much of what get information-wise seems to be driven by opinion. It's highlighted by what Prador says about Louis D as it happens. I've read posts by him before and think they're both really well written and informative, but they're subjective. When I buy a new television there are more parameters tested than I know what to do with, apples and oranges maybe but I hope I make a salient point.  

This kind of topic will always circle around personal preference but do you think there's a line somewhere? Can we get lucky with a £100 (for argument's sake) similar spec eyepiece that you'd struggle to tell the difference with on a blind test? 

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9 minutes ago, Peter Drew said:

Anyone querying the cost of a top of the range ultra wide eyepiece should take one apart before posting.    🙂

You'll have to humor me I'm afraid Peter 😄 I don't have knowledge or experience to get close to being able to answer that. It's great to see you pop up here though.

In your opinion, is there anyone doing a decent job ay copying these ultra wide eyepieces and doing a good job of it (for a noticeably lower cost), or do those prices truly reflect the manufacturing & testing process of getting these on the market?  

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What I was alluding to was the complexity of the high end wide field eyepieces.  Some have up to 8 lenses, several of which have different optical signs or meniscus in profile.  All have to be good optically, correctly centered and spaced and not least of all each surface multicoated for maximum transmission.  To do all this to the expected high standard is not cheap.  🙂 

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37 minutes ago, NotSoSuperNova said:

is there anyone doing a decent job ay copying these ultra wide eyepieces and doing a good job of it (for a noticeably lower cost), or do those prices truly reflect the manufacturing & testing process of getting these on the market?  

Yes there is: Explore Scientific (the 82 degree line). They are not cheap but considerably cheaper than TV Naglers.

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11 minutes ago, Peter Drew said:

What I was alluding to was the complexity of the high end wide field eyepieces.  Some have up to 8 lenses, several of which have different optical signs or meniscus in profile.  All have to be good optically, correctly centered and spaced and not least of all each surface multicoated for maximum transmission.  To do all this to the expected high standard is not cheap.  🙂 

Nor should it be cheap. There's a genuine market for quality goods no matter the sector, and for good reason. I have the best eyepieces I can afford in the hope that they offer me the best viewing experience. I'm sure most of us are in the same boat. 

I'm sure we could agree that the manufacturing process on high end eyepieces, while complex, will be automated to some degree and that eyepieces of a particular model will come out "almost" identical at the end. My question revolved around there being people out there who know that process and turning out Nagler-esk eyepieces under a different name and half the cost. If you're saying that's not possible then I'll take it as fact. It was a genuine question that I'll be happy to know the answer to.  

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When I first started out and was first made aware of TV eyepieces I remember thinking you must be mad to pay that much for one eyepiece. I found that opinion changed with time and experience.

I now currently own two tv ep's (although several other premium type eyepiece), but no naglers though. My 8mm delos, which is my favourite to use high power lump of glass, gives me views that are super and as an object it simply oozes class.

I also have an 8mm BST, which is also very nice to use and offers up some good views. It also looks a nice bit of kit and it is good to hold, but it doesn't have that ooze of class. However it was less than 20% of the cost. 

As an observer you must decide if the added cost of premium glass, with a probable added visual benefit of less than 5-10% is worth paying that add price for. (Think of the quality ooze ) 😈

Edited by bomberbaz
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3 minutes ago, Nik271 said:

Yes there is: Explore Scientific (the 82 degree line). They are not cheap but considerably cheaper than TV Naglers.

These were the first ones I thought of because of the 82 degree FOV. I've never looked through one but I'd be interested to see how they compare (in whichever way they're tested). A quick check shows that people say they're a great alternative to the Nagler but that it's a lot of money for the small improvement. Others say they prefer one or the other for personal reasons. It's a great example though. Perhaps they are very similar in terms of performance. 

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6 minutes ago, bomberbaz said:

When I first started out and was first made aware of TV eyepieces I remember thinking you must be mad to pay that much for one eyepiece. I found that opinion changed with time and experience.

I now currently own two tv ep's (although several other premium type eyepiece), but no naglers though. My 8mm delos, which is my favourite to use high power lump of glass, gives me views that are super and as an object it simply oozes class.

I also have an 8mm BST, which is also very nice to use and offers up some good views. It also looks a nice bit of kit and it is good to hold, but it doesn't have that ooze of class. However it was less than 20% of the cost. 

As an observer you must decide if the added cost of premium glass, with a probable added visual benefit of less than 5-10% is worth paying that add price for. (Think of the quality ooze ) 👿 

Great post. I'd like to be in the same position given the funds. I'm a sucker for the ooze, perceived or otherwise! 😁 

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There is this site, where he tests eyepieces at f/4 and f/10:

http://astro-talks.ru/forum/viewtopic.php?f=32&t=1483#p41976

You can go way down the page to the second chart where the links to the original tests can be found (plus a LOT more eyepieces.

And then, these, where eyepieces are tested at f/3.5 and f/7:

https://web.archive.org/web/20110622011950/http://cieletespace.fr/files/InstrumentTest/201102_test_oculaires.pdf
https://web.archive.org/web/20130829052725/http://www.cieletespace.fr:80/files/InstrumentTest/201306__6_oculaires_10mm.pdf

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10 minutes ago, Don Pensack said:

There is this site, where he tests eyepieces at f/4 and f/10:

http://astro-talks.ru/forum/viewtopic.php?f=32&t=1483#p41976

You can go way down the page to the second chart where the links to the original tests can be found (plus a LOT more eyepieces.

And then, these, where eyepieces are tested at f/3.5 and f/7:

https://web.archive.org/web/20110622011950/http://cieletespace.fr/files/InstrumentTest/201102_test_oculaires.pdf
https://web.archive.org/web/20130829052725/http://www.cieletespace.fr:80/files/InstrumentTest/201306__6_oculaires_10mm.pdf

This is a great link. That's the exact kind of resource I was looking for. Strange it's tucked away on a Russian forum and not widely available but it's a niche question maybe. It's great work from them regardless. Thanks for sharing.

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2 hours ago, NotSoSuperNova said:

Nor should it be cheap. There's a genuine market for quality goods no matter the sector, and for good reason. I have the best eyepieces I can afford in the hope that they offer me the best viewing experience. I'm sure most of us are in the same boat. 

I'm sure we could agree that the manufacturing process on high end eyepieces, while complex, will be automated to some degree and that eyepieces of a particular model will come out "almost" identical at the end. My question revolved around there being people out there who know that process and turning out Nagler-esk eyepieces under a different name and half the cost. If you're saying that's not possible then I'll take it as fact. It was a genuine question that I'll be happy to know the answer to.  

I have owned ~370 eyepieces and looked though many many more over the last 6 decades.

To my eye, no company producing an eyepiece for 50% the price of a TeleVue has equaled the TeleVue eyepiece.  None.

No copy by anyone has equaled the original.

There are eyepieces just as good, though, but they seem to sell for more.

And there are eyepieces that are pretty close that sell for less, but  a multi-point comparison will reveal the differences.

 

That doesn't mean you won't be happy with the lower-priced eyepieces, though.

For example, an out-of-focus field stop doesn't matter to me at all, so I may note that an eyepiece has that, but it wouldn't be a deal-breaker for me.

However, astigmatism at the edge of the field is my bête-noire, and even a little bit leaves me looking for a replacement.

(not that such a search is always successful--there is NO perfect eyepiece).

People ask me all the time if there is a  $300 eyepiece that is "the same as" a $600 eyepiece, and I answer no.  A $25K car is not the same as a $50K car.

But it can be very close--so close in some cases, it just might be the true bargain everyone is looking for, with 98% of the performance for 50% of the price.

Such eyepieces are few and far between, though.  And a careful reading of the threads here on SGL and on other forums reveals which they are.

 

What can be fairly said, though, is that there are some terrific eyepieces for less; in some cases a lot less.

And if you want eyepieces compatible with eyeglasses, TeleVue has some, but is not the only game in town.

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11 hours ago, NotSoSuperNova said:

These were the first ones I thought of because of the 82 degree FOV. I've never looked through one but I'd be interested to see how they compare (in whichever way they're tested). A quick check shows that people say they're a great alternative to the Nagler but that it's a lot of money for the small improvement. Others say they prefer one or the other for personal reasons. It's a great example though. Perhaps they are very similar in terms of performance. 

All my eyepieces are ES in 68 or 82 degrees. I am sure others will disagree and there are factors like eye relief and focal lengths and scopes to be taken in consideration, but I can’t discern a difference between those and the TV eyepieces I have owned with either my rather small refractor   (Starwave 102 ED-R) or any of the Newtonians I once owned 

Edited by Carl Au
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13 hours ago, NotSoSuperNova said:

Nor should it be cheap. There's a genuine market for quality goods no matter the sector, and for good reason. I have the best eyepieces I can afford in the hope that they offer me the best viewing experience. I'm sure most of us are in the same boat. 

I'm sure we could agree that the manufacturing process on high end eyepieces, while complex, will be automated to some degree and that eyepieces of a particular model will come out "almost" identical at the end. My question revolved around there being people out there who know that process and turning out Nagler-esk eyepieces under a different name and half the cost. If you're saying that's not possible then I'll take it as fact. It was a genuine question that I'll be happy to know the answer to.  

I don't think that anything of this nature is impossible, but it takes time.  Technology is quickly catching up with traditional skills and automation will produce reliable repeatability.  Hopefully providing top quality at lower prices.    🙂

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1 hour ago, Carl Au said:

All my eyepieces are ES in 68 or 82 degrees. I am sure others will disagree and there are factors like eye relief and focal lengths and scopes to be taken in consideration, but I can’t discern a difference between those and the TV eyepieces I have owned with either my rather small refractor   (Starwave 102 ED-R) or any of the Newtonians I once owned 

That may be true but if we consult our newly found chart (and believe said chart is accurate), you'll see that many of the 82 deg eyepieces are technically great (especially those in yellow), and even outperform the 68 deg range overall. But that's the beauty of this perhaps, if you like or prefer the 68 deg experience then more power to you. Sometimes we just like what we like. 

*Here's the link again if anyone is interested but after the first two columns you're looking at centre (to be ignored), middle and edge readings for the eyepiece in an F4 and F10 scope respectively. A reading of under 10 is visually perfect. angular size of aberration table

 

image.png.d3e2dc1af31bf24c0467025b5b654567.png

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The APM 20mm 100 degree is a pretty good rival to the 21 Ethos at a much lower price.

I’ve had a couple of each, but have now pretty much decided that 82 degree suits me better, more comfortable to view the entire field I find.

I’ve also had a couple of ES 30mm 82 degree and TV 31mm Nagler. I still have the Nagler; to me, particularly in my Genesis it just gives a flatter field with stars sharp out to the edge. The ES had a touch of field curvature and stars needed refocusing to be sharp at the edge. That may well be because the two TV products just work better together, but I also find my 24mm Panoptic to be the best of its kind. I don’t like it for lunar observing due to the geometric distortion but you can’t beat it for sharpness to the edge.

I think that’s where TV do excel, testing down to f4 so they perform well with all scopes. Many people rate the Morpheus very highly, and I do have a couple which I enjoy but am not totally convinced on their edge performance in faster scopes.

That said, everyone’s eyes vary, so there are plenty of different experiences and opinions, equally valid.

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33 minutes ago, Peter Drew said:

I don't think that anything of this nature is impossible, but it takes time.  Technology is quickly catching up with traditional skills and automation will produce reliable repeatability.  Hopefully providing top quality at lower prices.    🙂

Just for the record Peter. That table completely backs up what you said all along, and covers the entire Tele Vue line-up. They're a great manufacturer across the board (especially the Radian range). Interestingly though, I see the 100 degree, XWA range from Kunming United Optics has a couple of technically good entries on there, so perhaps that time isn't too far away. I don't think companies like Tele Vue have much to worry about in the near or long term regardless. 

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Don beat me to link to Ernest's tests.  I refer to them often as a double check on my own testing.  We're generally in pretty close alignment.

Here's Ernest's general eyepiece testing forum:

http://astro-talks.ru/forum/viewforum.php?f=32&sid=2ae665e58ed7af435f7ca61502fcbf44

and in organized/indexed form:

http://astro-talks.ru/forum/viewtopic.php?f=7&t=1897#p29513

An xls spreadsheet of my testing results:

Eyepiece-Data-Summary v1.0.xls

A few of my threads testing eyepieces:

 

Edited by Louis D
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I can't afford these top end EPs and am unlikely to ever have a 'scope in which I would see the notable difference, so the 'lesser' performance at the lower price is all I am ever going to experience! :D

Which is where the car analogy falls over for me as well I'm afraid Don! :D

Does the $25k car get me from A to B? Job done. ;)

 

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