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Old 06-07-2019, 08:14 PM
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gregbradley
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Can someone explain the TV eyepieces?

There are Panoptics, Naglers, Radians. Ethos, Delos, Delites and possibly others.

I am used to Panoptics, Naglers and Radians. I have had one Ethos and it was great but large and heavy.

Panoptics seem to have a smaller field of view but they don't kidney bean and are all round good optics and smallish.

Radians have a smaller FOV also and again less kidney bean/

Naglers have fabulous immersive wide views but kidney bean and can get quite large.

Delos and Delites I have no experience with. Are they any good?

Probably a loaded question but what are the best competitors to TV eyepieces? Pentax XW? Others?

I'd love some guidance for visual use of a 105 F6 APO mostly wideviewing.

Greg.

Greg.
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Old 06-07-2019, 08:58 PM
Wavytone (Nick)
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In short:

1. If you have a fast newtonian buy TV eyepieces and forget the rest.
2. If you have a refractor, buy Japanese eyepieces (Vixen, Pentax, Nikon, Masuyama).
3. If you have an SCT or mak, any modern eyepiece will work well enough.

The long:

The TV eyepieces - being American - are primarily suited to the US market which is dominated by big dobs ie fast newtonians, followed by SCTs. Hence most of their eyepieces suit fast newtonians.

In Japan the most popular scopes are small refractors and hence the Japanese eyepieces primarily suit that target market. Why does this matter ? What's different is:

1. The curvature of the focal plane of the refractors (convex) vs that of newtonians (concave), and eyepieces should ideally have field curvature to match so that the whole focal plane is in focus at once;

2. Fast newtonians have coma off-axis, its an inherent property of a parabolic mirror. Refractors do not.

Looking at Al Naglers (TV) patents shows that some of his designs had a modest amount of negative coma to partially compensate for that of a newtonian (better than none), yet in an SCT at f/10 the effect was not noticeable.
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Old 06-07-2019, 09:42 PM
Startrek (Martin)
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I use TV Delites, Delos, Panoptic and Ethos in my 12” F4.9 Goto dob and hardly even notice the coma to be honest ( unless your looking for it ) Although admittedly the view is slightly better using my Type 2 coma corrector set for each eye piece

My favourite eye pieces for Nebula , Galaxies and Clusters are the Panoptic 24mm , Panoptic 27mm and the Ethos 21mm

For planets the Delos 4.5mm, 6mm and Ethos 8mm

For Lunar just about any TV eye piece in my collection

All have a full set of TV Powermates for observing and for planetary and lunar imaging

I haven’t used any other eye pieces so can’t comment or compare to other high end quality eye pieces

My TV collection work well in my 6” f6 and 8” f5 imaging newts as well !!

I just love my TV collection

Cheers
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  #4  
Old 07-07-2019, 01:06 AM
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Ukastronomer (Jeremy)
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Have fun reading this

https://en.wikipedia.org/wiki/Eyepiece

I don't know what the laws are abroad but we in the UK have 1. The Consumer rights act and 2. The distance selling regulations.

The second is great, it allows you to buy, try and without any obligation...... return superb for checking out astro gear

My favorite eyepiece on my 120mm Triplet is an older celestron 2" 19mm Axiom that cost me about £120 twelve years ago, but always 2"



...
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Old 07-07-2019, 01:32 AM
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billdan (Bill)
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Jeremy in Aust' if you buy a product and want a refund because you have changed your mind, the supplier is not obligated to give a refund. The supplier may give a refund, but its up to them if they do or not. The law is on the suppliers side in this context.
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Old 07-07-2019, 01:35 AM
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Ukastronomer (Jeremy)
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Quote:
Originally Posted by billdan View Post
Jeremy in Aust' if you buy a product and want a refund because you have changed your mind, the supplier is not obligated to give a refund. The supplier may give a refund, but its up to them if they do or not. The law is on the suppliers side in this context.
That is the same here, I am talking distance selling regulations, eg, ordering and buying online then having it delivered, Not in Aus
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Old 07-07-2019, 05:57 AM
astro744
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Firstly go to the source for best information and advice.

See http://televue.com/engine/TV3b_page.asp?ID=2

and

http://televue.com/engine/TV3b_page.asp?id=154

and in particular http://televue.com/engine/TV3b_page....n=Advice&id=78

Secondly Televue also make and sell short refractors and they would not make eyepieces that did not work well in their own 'scopes.

I am yet to find a telescope that a Tele Vue eyepiece did not work well in. All are tested to f4 and all eyepieces in their range are of very high quality. The different types have different characteristics including focal length, apparent field of view and eye relief.

Tele Vue are very helpful over the phone and if you call them you may even get Al Nagler himself answering.

Authorised Australian dealer is Bintel. See https://www.bintel.com.au/product-ca...v=6cc98ba2045f and their sales and after sales service is first class when it comes to Tele Vue.
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Old 07-07-2019, 09:26 AM
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Camelopardalis (Dunk)
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Quote:
Originally Posted by Ukastronomer View Post
That is the same here, I am talking distance selling regulations, eg, ordering and buying online then having it delivered, Not in Aus
Jeremy, you’re missing Bill’s point...here in Australia, however or wherever you buy a product from, the seller is under no obligation to take it back unless it is faulty.

You must consider that outside of your UK/EU bubble, the world is a different place and each country has their own laws and regulations that often bear no resemblance to yours.

Apologies to the OP for going off topic.
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Old 07-07-2019, 07:22 PM
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Ukastronomer (Jeremy)
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Quote:
Originally Posted by Camelopardalis View Post
Jeremy, you’re missing Bill’s point...here in Australia, however or wherever you buy a product from, the seller is under no obligation to take it back unless it is faulty.

You must consider that outside of your UK/EU bubble, the world is a different place and each country has their own laws and regulations that often bear no resemblance to yours.

Apologies to the OP for going off topic.
That is why I said "Not in Aus " in my post
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