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Tele Vue Ethos

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#1 Anthony Dente

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Posted 17 September 2021 - 03:34 PM

Want to add a Tele Vue Ethos to use with my TMB 115 f/7 refractor.

Which one would you recommend...?

 

Thanks

Anthony



#2 ButterFly

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Posted 17 September 2021 - 03:40 PM

All of them.

 

What eyepieces do you have already?  Eyepieces are a set, so it's best not to be redundant.  If that's not an issue, then get them all.


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#3 areyoukiddingme

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Posted 17 September 2021 - 03:59 PM

Around 2mm exit pupil is likely to be most used. But the refractor will punch above its weight.

 

So the 10 or 13 is likely to be the most used.

 

Butterfly's comment brings up the issue that once you get one, well . . . let's just say you are going to want more.

 

That being the case, I'd think about both what you think would be a most-used eyepiece for that scope (and possibly others), and plan what step sequence you'd want.

 

For example, if you go with the 13, you probably wouldn't go for the 10 or 17.

 

Typical sequences are 6, 10, 17 or 8, 13, 21. 


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#4 StringfellowHawke

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Posted 17 September 2021 - 04:09 PM

I'll echo the previous sentiments about the Ethos being addictive. My first was the 21E and I was blown away by the massive FOV (invaluable for a manual dob). Within a year, I had traded out my collection for the 13, 8, 6 and 4.7 as well.   


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#5 Anthony Dente

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Posted 17 September 2021 - 07:02 PM

If I’m considering just one ethos, would you suggest a 10 or 13mm...?


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#6 MitchAlsup

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Posted 17 September 2021 - 07:19 PM

As to the Ethoi:: yes, indeed, get all of them

 

But wait:: the 9ES120 makes both the 13E and the 10E redundant. 9ES120 has the TFoV of the 13E and the magnification of the 10E (a bit higher actually.)

 

If you were to get only one Ethoi:: consider whether you want the lowest power E or something more midrange or higher end magnification. At the low end there is the 21E, at the higher end is the 4.7 (for an F/7 scope) and in the midrange is the 9ES120.


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#7 PKDfan

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Posted 17 September 2021 - 08:15 PM

Hi Anthony! Only you can say which power brings the most joy to you.

For me I am only considering only one Ethos, a 6mm. It will give me 150× and .66º true field.

I use my 6.5mm Morpheus at 135× for minimum resolve on planets.

That is the 6mm for you.
I'd like the 4.7mm Ethos for you at ~170×.

Maybe?
Depends upon if your seeing can handle it?

If a DSO fan then a 17 or 13mm Ethos would warrant a much closer look.

Ya if your rich try them all!
If not consider carefully your likes!

Good luck!



Clear skies & Good seeing

Edited by PKDfan, 17 September 2021 - 11:40 PM.

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#8 sanbai

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Posted 17 September 2021 - 09:10 PM

I would start by checking which set you want to have at the "end" of the journey (is there an end??). It's usual to skip some of the longest focal lengths. Usually to sets rule around:

* Nagler 31T5 + ethos 17 -10 (+ 6, 4.7, 3.7)
* Ethos 21 -13 -8 (+ 6 ?, 4.7, 3.7)

So, depending what set you prefer, you take the 13, or the 17 or 10 as starting one for general use. Of course, you may have preferences for wider true field or for high power and choose accordingly.
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#9 Dave Mitsky

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Posted 17 September 2021 - 09:13 PM

I would opt for a 10mm Ethos for use with that telescope if you're only planning on purchasing one of them.  An 8mm Ethos would also be a good choice.


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#10 wrvond

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Posted 17 September 2021 - 09:21 PM

I would opt for a 10mm Ethos for use with that telescope if you're only planning on purchasing one of them.  An 8mm Ethos would also be a good choice.

I think the 8 might be a better choice. I bought the 10mm first but decided I wanted more magnification due to all the empty AFoV surrounding planetary targets, so I got the 8mm. It was better, but I ended up getting the 6. After that I gave in and got them all because the “best choice” varies depending on what I’m looking at. ;)


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#11 CrazyPanda

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Posted 17 September 2021 - 09:26 PM

If you want to do planetary observing, get the 6mm. 134x is good enough for planetary on those nights where the atmosphere won't cooperate, but still enough to show nice detail when the atmosphere is calm. The 6 is very sharp and has excellent contrast.

 

If you want to do general deep sky observing, get the 13mm for a ~2mm exit pupil. The view will pull you right in.


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#12 Spikey131

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Posted 17 September 2021 - 10:43 PM

Which one would I choose?  That depends upon what I wanted to use it for.  Is it for low power, wide angle views of the Milky Way?  Do you have a manual mount and want a high magnification 100 degree EP to watch the planets as they drift across the field?

 

In my refractor I most commonly us an Ethos that gives around 100x and a 1mm exit pupil.  For you, that would be an 8mm.  But I would need to know more about your situation to know if that is best for you.  

 

Below is an image of a chart generated on the TV website for your scope.  It shows all the Ethoi and the stats for each for your scope.

Attached Thumbnails

  • A2C3FF63-1BD6-471C-B0D9-89AE4E4B6EF0.jpeg

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#13 Allan Wade

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Posted 18 September 2021 - 02:16 AM

If I’m considering just one ethos, would you suggest a 10 or 13mm...?

The 10 and 13 are both great eyepieces and it really wouldn’t matter which you pick as you’ll enjoy both in your scope. If you really, really know you’ll only get one, then go the 10. Most people get addicted and keep building out their collection. The 13 sits perfectly in the 21/13/8/6 which I consider the ultimate, minimalist Ethos set.


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#14 Piero DP

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Posted 18 September 2021 - 02:32 AM

Between those focal lengths, you might also want to consider the 12.5mm Docter UWA.
It is not a TeleVue Ethos, but it's a sublime eyepiece.

Just suggesting, as you asked advise for an eyepiece only.
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#15 Jon Isaacs

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Posted 18 September 2021 - 03:42 AM

Want to add a Tele Vue Ethos to use with my TMB 115 f/7 refractor.

Which one would you recommend...?

 

Thanks

Anthony

Anthony:

 

What eyepieces do you currently own?

 

What are your skies like?

 

What do you like to look at?

 

What kind of mount do you own?

 

My own thinking would be one of the longer focal lengths.  Planetary viewing, double star viewing requires a number of eyepieces so that you can optimize the magnification for the current conditions.  A single Ethos for planetary is not really that useful because sometimes it might be the right eyepiece but most of the time, it probably won't be.  

 

With a 115mm F/7, the 21mm Ethos would provide a 2.6 degree TFoV at 38x with a 3mm exit pupil.  That would be a very nice low power view.  

 

Jon


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#16 russell23

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Posted 18 September 2021 - 07:42 AM

Having primarily used 4” to 4.7” APO’s for quite a few years now I would agree with the suggestion for the 6mm Ethos. It will provide good image scale and exit pupil for the Moon, planets, and globular clusters and other DSO that you want to really focus in on. 

 

With my 102mm f/11 ED doublets I spend most of my observing time with an eyepiece in the 30-40mm Fl range (28-38x) and then the 7mm APM XWA (160x).  If the seeing can’t handle 160x I drop back to the 9mm Morpheus (125x).  For some objects I want a brighter exit pupil and go with the 14mm Delos. 

 

But my experience with 4” f/7, 4” f/11, 4.7” f/7.5 APOs is that something between 125x and 170x is my most used magnification as long as seeing allows. The last few times I’ve been out my observing has been 95% 40mm XW (28x) and 7mm APM (160x) with my 4” f/11 refractor. The remaining time was the 14mm Delos.

 

So IME if you start with the 13mm or 10mm Ethos you are going to find yourself wanting to push past that magnification quite often.  If you don’t want the higher magnification then I would go with a 17mm or 21mm Ethos.


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#17 sanbai

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Posted 18 September 2021 - 08:21 AM

Between those focal lengths, you might also want to consider the 12.5mm Docter UWA.
It is not a TeleVue Ethos, but it's a sublime eyepiece.

Just suggesting, as you asked advise for an eyepiece only.

The issue is that this eyepiece is out of production and no vendor has stock. One needs to place an ad for it in the classifieds and (lot of) luck.
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#18 sanbai

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Posted 18 September 2021 - 08:29 AM

As usual everybody has a different suggestion. That's perfectly normal and expected (otherwise the market would have much less to offer).

Jon posted good questions that will help the OP decide.

There's not much to worry about a "bad decision", because there is no eyepiece to rule all the others out and all Ethos are excellent (if you like their parameters, I do). Whatever you buy you will use it, and others will follow to extend the possibilities.

Eyepiece shopping is a journey that can last a life time. Enjoy this journey.
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#19 Piero DP

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Posted 18 September 2021 - 08:41 AM

The issue is that this eyepiece is out of production and no vendor has stock. One needs to place an ad for it in the classifieds and (lot of) luck.

It has changed name. Now it is called Noblex, but it is the same eyepiece: https://noblex-germa...ics/uwa-ocular 


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#20 sanbai

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Posted 18 September 2021 - 08:47 AM

It has changed name. Now it is called Noblex, but it is the same eyepiece: https://noblex-germa...ics/uwa-ocular

Yes, I know it changed names. Buy Noblex took it out of production. Whatever the name/brand, this eyepiece is not in stock anymore.
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#21 MrRoberts

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Posted 18 September 2021 - 10:13 AM

In my 120 (840mm fl) I usually use the 17E for low power, the 8E to get a more specific view and my 4.5D for that up close and personal look-see. 


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#22 Tank

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Posted 18 September 2021 - 10:58 AM

4.7 or the 3.7 IMHO
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#23 Starman1

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Posted 18 September 2021 - 12:10 PM

Between those focal lengths, you might also want to consider the 12.5mm Docter UWA.
It is not a TeleVue Ethos, but it's a sublime eyepiece.

Just suggesting, as you asked advise for an eyepiece only.

It is no longer made.  Good luck finding a used one.


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#24 CrazyPanda

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Posted 18 September 2021 - 12:58 PM

Between those focal lengths, you might also want to consider the 12.5mm Docter UWA.
It is not a TeleVue Ethos, but it's a sublime eyepiece.

Just suggesting, as you asked advise for an eyepiece only.

Alternatively, get the Nikon NAV-HW 12.5, which comes with a barlow to make it a 10mm eyepiece, thereby getting two eyepieces in one. Plus eye relief is better than the 13 Ethos or 10 Ethos.


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#25 Anthony Dente

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Posted 18 September 2021 - 07:45 PM

Anthony:

 

What eyepieces do you currently own?

 

What are your skies like?

 

What do you like to look at?

 

What kind of mount do you own?

 

My own thinking would be one of the longer focal lengths.  Planetary viewing, double star viewing requires a number of eyepieces so that you can optimize the magnification for the current conditions.  A single Ethos for planetary is not really that useful because sometimes it might be the right eyepiece but most of the time, it probably won't be.  

 

With a 115mm F/7, the 21mm Ethos would provide a 2.6 degree TFoV at 38x with a 3mm exit pupil.  That would be a very nice low power view.  

 

Jon




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