19 replies to this topic

[korea-mk14]

Hello, I am a 20-inch dob user in South Korea.
My eyepiece. Ethos 13mm for sale
Should I buy Ethos 3.7mm or 17mm? Medium magnification overlaps
I love Docter and Apollo. I used Nikon 12.5mm and sold it because I love televue.
docter vs Apollo = apollo win

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Edited by korea-mk14, 03 November 2024 - 09:58 PM.

[SeattleScott]

I don’t know what your focal length is, but for a 20” it is hard to imagine you would get much use out of a 3.7mm.

So basically you will have a gap between the Apollo 11 and 21 Ethos. Ideally something about 15mm. 85-100 AFOV. Not a lot in that range. 17mm almost feels too close to 21. 21 is 24% more than 17 while 17 is 54% more than 11, plus the 17 has more AFOV than the 11. Unfortunately not a lot of obvious options in the 14-16 range. The Meade 15mm MWA probably would be a little outclassed. A 16 Nagler has snug ER compared to your other options. There is the 17HW with extender to make it 14, although you already sold the 12.5, and there could be a slight compatibility issue with P2 (minor I’m sure but you seem like the discriminating type).

Ultimately the 17 Ethos probably works as well as anything. The spacing won’t be ideal but it is likely the best option available. The Pentax 16.5XW could be worth considering as well, but it is only half a mm different and you prefer Televue, and probably don’t care about paying more for a heavier Televue eyepiece.

Edited by SeattleScott, 03 November 2024 - 10:31 PM.

[korea-mk14]

James Webb Space Telescope
Thank you so much for your response.

[25585]

Had you kept your Nikon HW, you could have used it as a 10mm.

[Olimad]

James Webb Space Telescope
Thank you so much for your response.

Hello Korea-mk14,

 

You have a really great set and I am sure you will find some great advices/help/answers from others CNers.

 

But, just for you to know "James Webb Space Telescope" is not a nickname, It is a level of participation.

You were answering to "SeattleScott".

You have as nickname "Korea-mk14", and your participation level is "Lift Off" for now.

My nickname is "Olimad" and my actual participation-level is "Apollo", which seems to be, if you put "11" after It, one of the best eyepiece that s the world have ever known... Seems that you can testify about It.

 

It is just to make thing easier to follow.

 

Welcome and clear skies

Edited by Olimad, 04 November 2024 - 08:48 AM.

[SeattleScott]

Had you kept your Nikon HW, you could have used it as a 10mm.

But it would have competed with the Apollo 11, which he prefers.

[idahoeng]

But, just for you to know "James Webb Space Telescope" is not a nickname, It is a level of participation.

You were answering to "SeattleScott".

You have as nickname "Korea-mk14", and your participation level is "Lift Off" for now.

My nickname is "Olimad" and my actual participation-level is "Apollo", which seems to be, if you put "11" after It, one of the best eyepiece that s the world have ever known... Seems that you can testify about It.

 

It is just to make thing easier to follow.

 

Hello Olimad,

 

Thank you for that explanation !   I never know how those titles were assigned. 
 

IdahoEng

[Olimad]

Hello Olimad,

 

Thank you for that explanation !   I never know how those titles were assigned. 
 

IdahoEng

You are welcome, Vostock 1.......

Edited by Olimad, 04 November 2024 - 11:10 AM.

[jrazz]

And here are the levels:

https://www.cloudyni...tles-and-ranks/

[jrazz]

Oh, I see it has been updated: https://www.cloudyni...1760-cn-titles/

 

I just got FMTTM... Need to work on that Cosmos now.

[Mike Q]

Well the question is how good are your skies?   On a guess i would say your 20 inch has at least 2000mm worth of focal length and that 3.8 would get you well north of 500x.  The question becomes will your skies let you do that.  In my world the 17mm would be used frequently.  

[Symui]

Hello, I am a 20-inch dob user in South Korea.
My eyepiece. Ethos 13mm for sale
Should I buy Ethos 3.7mm or 17mm? Medium magnification overlaps
I love Docter and Apollo. I used Nikon 12.5mm and sold it because I love televue.
docter vs Apollo = apollo win

 

"docter vs Apollo = apollo win"

Thanks for sharing that I just might have to pick one up in the classifieds on the rare occasion that one is listed. 

 

From my experience and everyone else I know

Ethos 17mm vs Nikon Nav 17mm HW = Nikon Nav 17mm HW Wins!

 

I'm an Ethos fan and had the E17 for several years but one look through the Nikon Nav 17mm HW and I quickly realised the E17 had been eclipsed.  The Nav 17mm HW redefines sharpness, it's truly an incredible eyepiece worth serious consideration for anyone looking for a 17mm 100 or 102 FOV.   The Nikons can be purchased direct from Japan.  I have purchased several eyepieces from the dealer in Osaka and was very satisfied with the transaction. 

[Starman1]

Suggestion: don't sell the 13mm Ethos.

You don't need the 10mm Ethos because of the 11mm Apollo

11 to 13 to 21 seems OK for what are likely the targets you are looking for.

Unless you are constantly feeling the need for an eyepiece in between the 13mm and 21mm, I think your set of eyepieces is fine as is.

As has been mentioned, the 3.7mm Ethos SX would result in a very high magnification, so here is the question:

Do you use the 4.7mm a lot?

If the answer is yes, then you would likely use the 3.7mm.

If the answer is no, then you can pass on the 3.7mm

 

For a 20", 

<200x  low power

200x-400x  medium power

400-600x high power

600-1000x ultra high power.

You have to have very very good seeing to use 600x+, but 500x would be usable at times.

Assuming a 20" f/4, that is a focal length of 2337mm with the Paracorr, and the 4.7mm yields about 500x.

[korea-mk14]

Hello Korea-mk14,
 
You have a really great set and I am sure you will find some great advices/help/answers from others CNers.
 
But, just for you to know "James Webb Space Telescope" is not a nickname, It is a level of participation.
You were answering to "SeattleScott".
You have as nickname "Korea-mk14", and your participation level is "Lift Off" for now.
My nickname is "Olimad" and my actual participation-level is "Apollo", which seems to be, if you put "11" after It, one of the best eyepiece that s the world have ever known... Seems that you can testify about It.
 
It is just to make thing easier to follow.
 
Welcome and clear skies

Thank you, I didn't know much about this place, I understand now.
Apollo 11mm was definitely brighter and better resolution than the Docter when you look at m13

Edited by korea-mk14, 04 November 2024 - 09:36 PM.

[korea-mk14]

Had you kept your Nikon HW, you could have used it as a 10mm.

Hi. I guess you like Docter 12.5mm. I've seen a lot of previous posts. I knew the Nikon 12.5mm was better, but I didn't like the design. I like the green letters. Also, Docter 12.5mm is a difficult item to get. I wanted to collect. Oh, and I have eic10 lenses, so I can use docter in 10mm. If you look at the picture, I'm using docter and eic10 together.

[korea-mk14]

Well the question is how good are your skies?   On a guess i would say your 20 inch has at least 2000mm worth of focal length and that 3.8 would get you well north of 500x.  The question becomes will your skies let you do that.  In my world the 17mm would be used frequently.

I'm using an f3.5 Orion 1/10 mirror.
Now we've seen about 90% of Herschel 400. The sky is fine.
The focal length is 1933 using p2.I don't use 4.7mm very often either ^^;;;;
Thank you.

Edited by korea-mk14, 04 November 2024 - 09:46 PM.

[korea-mk14]

"docter vs Apollo = apollo win"
Thanks for sharing that I just might have to pick one up in the classifieds on the rare occasion that one is listed. 
 
From my experience and everyone else I know
Ethos 17mm vs Nikon Nav 17mm HW = Nikon Nav 17mm HW Wins!
 
I'm an Ethos fan and had the E17 for several years but one look through the Nikon Nav 17mm HW and I quickly realised the E17 had been eclipsed.  The Nav 17mm HW redefines sharpness, it's truly an incredible eyepiece worth serious consideration for anyone looking for a 17mm 100 or 102 FOV.   The Nikons can be purchased direct from Japan.  I have purchased several eyepieces from the dealer in Osaka and was very satisfied with the transaction.

Hello, I am well aware. Nikon Nav hw is the best eyepiece. Just didn't like the design and I love the green letters. The performance difference wasn't that big. I'm Korean but I love American televue.

[korea-mk14]

Suggestion: don't sell the 13mm Ethos.
You don't need the 10mm Ethos because of the 11mm Apollo
11 to 13 to 21 seems OK for what are likely the targets you are looking for.
Unless you are constantly feeling the need for an eyepiece in between the 13mm and 21mm, I think your set of eyepieces is fine as is.
As has been mentioned, the 3.7mm Ethos SX would result in a very high magnification, so here is the question:
Do you use the 4.7mm a lot?
If the answer is yes, then you would likely use the 3.7mm.
If the answer is no, then you can pass on the 3.7mm
 
For a 20", 
<200x  low power
200x-400x  medium power
400-600x high power
600-1000x ultra high power.
You have to have very very good seeing to use 600x+, but 500x would be usable at times.
Assuming a 20" f/4, that is a focal length of 2337mm with the Paracorr, and the 4.7mm yields about 500x.

Hello! I've seen a lot of your posts.
P2 setting method, ethtos 6,8mm of 2" barrel etc. have helped me so much. Thank you so much. I trust you the most. Your writings were too objective and reliable. I don't use 4.7mm very often. I will respect your opinion. Thank you.
I am F3.5/1733
P2 = F4/1933

Edited by korea-mk14, 04 November 2024 - 09:24 PM.

[korea-mk14]

This is my telescope.
F3.5
Focal Distance 1733
Orion 500 mm F3.5 - 1/10 Lambda

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Edited by korea-mk14, 04 November 2024 - 09:34 PM.

[Starman1]

Hello! I've seen a lot of your posts.
P2 setting method, ethtos 6,8mm of 2" barrel etc. have helped me so much. Thank you so much. I trust you the most. Your writings were too objective and reliable. I don't use 4.7mm very often. I will respect your opinion. Thank you.
I am F3.5/1733
P2 = F4/1933

If you use the 6mm and 8mm Ethos as 2", their setting is H with the eyepiece pulled 0.4" out of the top of the Paracorr.

That is safe if barrel extenders are added to the 2" skirts.

I think you know that, but others may not, which is why I make mention of it here.

It sounds like you have a no-ladder 20".  Excellent.