Jump to content

SkySurveyBanner.jpg.21855908fce40597655603b6c9af720d.jpg

10mm Delos or 9mm Nagler


Stardaze

Recommended Posts

I don't seem to need to fold the eyecups down to see the full AFoV with my Ethos. I did with the ES 100's though.

I love the 8mm Ethos in my 12 inch dob. 199x and the views of globulars and planetary nebs are amazing :grin:

  • Like 1
Link to comment
Share on other sites

33 minutes ago, John said:

I don't seem to need to fold the eyecups down to see the full AFoV with my Ethos. I did with the ES 100's though.

I love the 8mm Ethos in my 12 inch dob. 199x and the views of globulars and planetary nebs are amazing :grin:

I dream of mags of 199x 😂

what I mean is, I put eyepiece extenders on the ethos and fold the cups down on the eyepiece extenders. I’m finding this very comfortable viewing as I don’t have much luck hovering and get on better with a firmer eye cup. It really does make them feel like using a wider Delos to me. 

  • Like 1
Link to comment
Share on other sites

38 minutes ago, Dantooine said:

I dream of mags of 199x 😂

what I mean is, I put eyepiece extenders on the ethos and fold the cups down on the eyepiece extenders. I’m finding this very comfortable viewing as I don’t have much luck hovering and get on better with a firmer eye cup. It really does make them feel like using a wider Delos to me. 

I don't like "hovering" either. I like to nestle my eye socket into a soft eyecup. The TV Delos and Ethos eyecups are great for this. I think quite a lot of whether we "like" eyepieces or not is down to ergonomics, preferences, face contours etc.

Perhaps there is a niche for a bespoke eyepiece "fitting" service in a post virus world. "Suits you sir" :grin:

Suits you sir: business wear vs. casual | The wannabe VC

Link to comment
Share on other sites

1 hour ago, Stardaze said:

I like nestling too 😀

I am right in thinking that an extension will reduce the amount of focuser extension needed

Im not quite sure what you mean. How I have it now My eye is the same distance from lens as it is with the standard ethos eye cup up. The only real difference is it’s firmer. It’s just a comfort thing. 

Link to comment
Share on other sites

Helpful information about focus positions:

21mm and 17mm Ethos:  0.4" IN from the focal plane of the scope (i.e. how much in travel is necessary when the focal plane of the scope is right at the top of the focuser)

13mm and 10mm Ethos: 0.3" OUT from the focal plane

3.7mm and 4.7mm Ethos (used as 2" eyepieces with included adapters): 0.3" OUT from the focal plane.

6mm and 8mm Ethos (used as 2" eyepieces with barrel extenders added): 0.7" OUT from the focal plane.

Used as 2" eyepieces, the Ethos eyepieces focus up to 1.2" apart!

 

Any of the above used as 1.25" eyepieces: focal position will vary according to the adapter used.

For example: 6mm and 8mm Ethos used as 1.25" in the Paracorr adapter: 0.3" IN from the focal plane.  If you used an adapter 10.5mm thick, then they would focus 0.6" IN from the focal plane.

Lift the eyepiece up, and more IN focus is needed.  Drop the eyepiece down and the eyepiece needs more OUT focus.

That's logical, right.  And it means that with a selection of 1.25" adapters, you can come close to parfocalizing all your eyepieces.  Adapters come with heights from -0.5" to +0.6".

 

One more thing: the T6 9mm Nagler focuses 0.25" OUT from the focal plane.

Edited by Don Pensack
  • Thanks 1
Link to comment
Share on other sites

23 minutes ago, Don Pensack said:

6mm and 8mm Ethos (used as 2" eyepieces with barrel extenders added): 0.7" OUT from the focal plane.

So pretty similar to the 12mm NT4 at 0.78" OUT.  I had to add five 4mm thick O rings and a 20mm 2" extension ring to the 2" skirt to make it roughly parfocal with my other eyepieces that focus near the shoulder (reference surface).  It was practically unusable otherwise because it required so many turns of the focuser to reach focus.

  • Like 1
Link to comment
Share on other sites

4 hours ago, Louis D said:

So pretty similar to the 12mm NT4 at 0.78" OUT.  I had to add five 4mm thick O rings and a 20mm 2" extension ring to the 2" skirt to make it roughly parfocal with my other eyepieces that focus near the shoulder (reference surface).  It was practically unusable otherwise because it required so many turns of the focuser to reach focus.

I found it just simpler to use them as 1.25" eyepieces and reduce the necessary range of the focuser.

Of course, using a Paracorr, they are all parfocal anyway.

  • Like 1
Link to comment
Share on other sites

53 minutes ago, Don Pensack said:

I found it just simpler to use them as 1.25" eyepieces and reduce the necessary range of the focuser.

IIRC, in 1.25" mode, the 12mm NT4 required about 0.25" of IN focus relative to the shoulder, which was a pain in it's own right.

55 minutes ago, Don Pensack said:

Of course, using a Paracorr, they are all parfocal anyway.

That's the main reason I parfocalized it the way I did.  When I use the GSO CC, everything needs to focus within about 5mm of the shoulder with the spacing I have to get 95%+ coma correction.  The 12mm NT4 was so far off that uncorrected coma was plainly obvious without having to go searching for it.  With parfocalization, coma is no longer noticeable.  With the correction level I'm at with the GSO CC, eyepiece field curvature and residual edge astigmatism once again dominate the view, so I have never felt the need to get a Paracorr.

Link to comment
Share on other sites

15 hours ago, Don Pensack said:

Helpful information about focus positions:

21mm and 17mm Ethos:  0.4" IN from the focal plane of the scope (i.e. how much in travel is necessary when the focal plane of the scope is right at the top of the focuser)

13mm and 10mm Ethos: 0.3" OUT from the focal plane

3.7mm and 4.7mm Ethos (used as 2" eyepieces with included adapters): 0.3" OUT from the focal plane.

6mm and 8mm Ethos (used as 2" eyepieces with barrel extenders added): 0.7" OUT from the focal plane.

Used as 2" eyepieces, the Ethos eyepieces focus up to 1.2" apart!

 

Any of the above used as 1.25" eyepieces: focal position will vary according to the adapter used.

For example: 6mm and 8mm Ethos used as 1.25" in the Paracorr adapter: 0.3" IN from the focal plane.  If you used an adapter 10.5mm thick, then they would focus 0.6" IN from the focal plane.

Lift the eyepiece up, and more IN focus is needed.  Drop the eyepiece down and the eyepiece needs more OUT focus.

That's logical, right.  And it means that with a selection of 1.25" adapters, you can come close to parfocalizing all your eyepieces.  Adapters come with heights from -0.5" to +0.6".

 

One more thing: the T6 9mm Nagler focuses 0.25" OUT from the focal plane.

Thanks Don that’s really helpful. At least I know that the 8 and 6 are going to both be the same, the most problematic at that. 

Link to comment
Share on other sites

4 minutes ago, Stardaze said:

Thanks Don that’s really helpful. At least I know that the 8 and 6 are going to both be the same, the most problematic at that. 

The 8 and 6 Ethos look identical as well. In low light its easy to muddle them up !

 

  • Like 1
  • Haha 1
Link to comment
Share on other sites

23 hours ago, Don Pensack said:

Helpful information about focus positions:

21mm and 17mm Ethos:  0.4" IN from the focal plane of the scope (i.e. how much in travel is necessary when the focal plane of the scope is right at the top of the focuser)

13mm and 10mm Ethos: 0.3" OUT from the focal plane

3.7mm and 4.7mm Ethos (used as 2" eyepieces with included adapters): 0.3" OUT from the focal plane.

6mm and 8mm Ethos (used as 2" eyepieces with barrel extenders added): 0.7" OUT from the focal plane.

Used as 2" eyepieces, the Ethos eyepieces focus up to 1.2" apart!

 

Any of the above used as 1.25" eyepieces: focal position will vary according to the adapter used.

For example: 6mm and 8mm Ethos used as 1.25" in the Paracorr adapter: 0.3" IN from the focal plane.  If you used an adapter 10.5mm thick, then they would focus 0.6" IN from the focal plane.

Lift the eyepiece up, and more IN focus is needed.  Drop the eyepiece down and the eyepiece needs more OUT focus.

That's logical, right.  And it means that with a selection of 1.25" adapters, you can come close to parfocalizing all your eyepieces.  Adapters come with heights from -0.5" to +0.6".

 

One more thing: the T6 9mm Nagler focuses 0.25" OUT from the focal plane.

Don, in the above explanation, were the 10 and 13 Ethos being used as 2” eyepieces?

Link to comment
Share on other sites

5 hours ago, RickEm said:

Don, in the above explanation, were the 10 and 13 Ethos being used as 2” eyepieces?

Yes, they were. Sorry.  They could be used as 1.25" eyepieces.  I use a Paracorr, and they cannot be used as 1.25" eyepieces in the Paracorr, but they certainly could without it.

I don't know where they would focus though.  It's outside the range of +0.3" to -0.4" from the focal plane, for sure.

Edited by Don Pensack
Link to comment
Share on other sites

Is anyone else using Ethos in 1.25” mode? Seems strange to me that they need extra extension / rings for best 2” adaptation, especially given the price point. Was there a concession in there to make them dual sized? 

Link to comment
Share on other sites

8 minutes ago, Stardaze said:

Is anyone else using Ethos in 1.25” mode? Seems strange to me that they need extra extension / rings for best 2” adaptation, especially given the price point. Was there a concession in there to make them dual sized? 

In my case, I only use the barrel extensions to enable me to use 2 inch filters with the 13, 8 and 6mm Ethos. Otherwise the 2 inch barrels work fine with no extensions IMHO.

 

 

 

  • Like 1
Link to comment
Share on other sites

49 minutes ago, Don Pensack said:

Yes, they were. Sorry.  They could be used as 1.25" eyepieces.  I use a Paracorr, and they cannot be used as 1.25" eyepieces in the Paracorr, but they certainly could without it.

I don't know where they would focus though.  It's outside the range of +0.3" to -0.4" from the focal plane, for sure.

Thanks for clarifying, Don.  I use my 13 Ethos as a 2” eyepiece.

 

Rick

Link to comment
Share on other sites

7 hours ago, John said:

In my case, I only use the barrel extensions to enable me to use 2 inch filters with the 13, 8 and 6mm Ethos. Otherwise the 2 inch barrels work fine with no extensions IMHO.

 

 

 

I think that’s handy as I’m sure you would have the option of using either sized filter. Might actually save a bit of money and buy the 1.25” baader Contrast boost filter as that will only be used for planets with the 8mm and 6mm (when I add one). 

Link to comment
Share on other sites

18 hours ago, John said:

In my case, I only use the barrel extensions to enable me to use 2 inch filters with the 13, 8 and 6mm Ethos. Otherwise the 2 inch barrels work fine with no extensions IMHO.

 

 

 

I put all my 2" filters on the front of the Paracorr.

Link to comment
Share on other sites

10 hours ago, Stardaze said:

I think that’s handy as I’m sure you would have the option of using either sized filter. Might actually save a bit of money and buy the 1.25” baader Contrast boost filter as that will only be used for planets with the 8mm and 6mm (when I add one). 

The 1.25" filters will fit all the Ethos eyepieces except the 17mm and 21mm.

  • Like 1
Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue. By using this site, you agree to our Terms of Use.