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Best 6mm class eyepiece for contrast on close, unequal double stars

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#1 John Fitzgerald

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Posted 11 December 2019 - 11:58 PM

Ortho, Delos, or?   Opinions and experiences?



#2 Traveler

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Posted 12 December 2019 - 12:05 AM

Why are you looking for a 6mm?

At that focallenghth and application i much prefer the TV 3-6 zoom. 


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#3 John Fitzgerald

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Posted 12 December 2019 - 12:10 AM

Why are you looking for a 6mm?

At that focallenghth and application i much prefer the TV 3-6 zoom. 

Gives 203x in my refractor.   I have a 6mm Baader green label ortho already.  Wondering if there is something better for transmission and contrast.



#4 Cotts

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Posted 12 December 2019 - 12:13 AM

I use a Nagler 5mm and a Nagler 3-6 zoom (at 3mm if I really want to 'dig in'....)

 

I can discern no  difference between the two other than the generous field of the 5mm.... 

 

The limiting factor for picking out a faint companion  as you get into  magnifications of several hundreds is far more likely to be the seeing.  A secondary problem might be haze and glare if the eyepiece is dirty or slightly fogged.

 

Dave


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#5 John Fitzgerald

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Posted 12 December 2019 - 12:17 AM

I use a Nagler 5mm and a Nagler 3-6 zoom (at 3mm if I really want to 'dig in'....)

 

I can discern no  difference between the two other than the generous field of the 5mm.... 

 

The limiting factor for picking out a faint companion  as you get into  magnifications of several hundreds is far more likely to be the seeing.  A secondary problem might be haze and glare if the eyepiece is dirty or slightly fogged.

 

Dave

Yes, I am too familiar frown.gif with bad seeing.


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#6 25585

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Posted 12 December 2019 - 01:44 AM

Baader Morpheus 6.5mm or Vixen SLV 6mm.


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#7 Astro-Master

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Posted 12 December 2019 - 01:54 AM

I also use the Nagler 3-6 zoom, its my favorite high power eyepiece for my 105mm APO.

 

Its perfect for getting just the right separation on doubles, or planetary detail with changing seeing conditions with a twist of the wrist, and you don't have to refocus.   

 

Thank you Al Nagler, for making such a wonderful zoom eyepiece.



#8 Jon Isaacs

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Posted 12 December 2019 - 01:56 AM

Another factor making close, unequal splits difficult:

 

Bad eyes...  They're not what they once were. 

 

Jon


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#9 Monsai52

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Posted 12 December 2019 - 02:04 AM

I haven't found anything in that approximate f/l that will beat one of the old 6.6mm Cave Orthostars, for tight doubles.

 

Best regards,


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#10 emilslomi

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Posted 12 December 2019 - 02:55 AM

If you have a tracking mount, try a monocentric to minimize the impact of the eyepiece. I have the Burgess flavor in 6 mm, KK Abbe orthos and the TV 3-6 zoom. In the center of the FOV, the Burgess outclasses the orthos and the TV zoom. But that center is narrow! For double stars at very high magnifications, a tracking mount is really a must - unless the F of your scope is large (>8 better >10), which cleans up a bit of the outer part of the FOV. And the eye relief is small. But if that is ok with you, at <100$ it is worth a shot.

 

Emil


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#11 213Cobra

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Posted 12 December 2019 - 04:18 AM

Takahashi 5.7mm UW, then Tak TOE shorter than that. -Phil



#12 leviathan

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Posted 12 December 2019 - 05:41 AM

Best 6mm EP I owned was ZAO-II.



#13 YAOG

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Posted 12 December 2019 - 04:22 PM

Ortho, Delos, or?   Opinions and experiences?

For a dedicated planetary eyepiece the ZAO II is basically a class of it's own. The monos are pretty close too. But it is hard to justify the cost of these exotics unless you have the scope, diagonal and seeing to tease out their advantages. Bang for the buck used UO VT Orthos or the later fully multi-coated orthos deliver the goods in anything less than 9/10 seeing. 

 

I love the TeleVue 3-6mm Nagler Zoom for variable conditions for the speed and ease of nailing exactly what the conditions can reveal moment to moment, it is surprisingly close to the 4-element orthos. And have a bit more room for Saturn's moons.


Edited by YAOG, 13 December 2019 - 12:00 PM.

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#14 j.gardavsky

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Posted 12 December 2019 - 04:57 PM

Yes, the TV 3mm - 6mm Nagler Zoom is a remarkable performer and a versatile eyepiece, allowing to precisely zoom into the right magnification.

My best 6mm ortho is the discontinued Pentax SMC.

 

Best,

JG


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#15 CollinofAlabama

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Posted 12 December 2019 - 09:36 PM

I use the very good, and very affordable, Baader Classic Ortho 6mm.  Like it very much, but one has got to be able to handle tight eye relief, tho the volcano top design makes that much easier.  If you require a lot of eye relief because you observe with glasses, the BCO 18mm plus Celestron X-Cel LX 3x barlow should make a nice 6-ish mm resultant focal length ocular.  All these are pretty cheap.  I like the Nagler 5mm T6, but 5mm can stress the skies a bit much.  6mm is more commonly useful, my skies often not steady enough for anything more powerful.


Edited by CollinofAlabama, 12 December 2019 - 09:37 PM.

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#16 YAOG

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Posted 13 December 2019 - 11:55 AM

Ortho, Delos, or?   Opinions and experiences?

John, I forgot to ask, what does 6mm net in terms of magnification for your target scope?

 

I'm in southern California and we don't have the best skies but even here an average night in the suburbs when observing planets with the DL's 100mm f/9 I tend to work within the 150-200x range. Under better skies I setup the P/AT 130mm f/6 and top out at 260x. To use more magnification than this needs much darker skies and a 2 or more hour car trip out of the city where the M10" or C11" can do their best work. 



#17 John Fitzgerald

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Posted 13 December 2019 - 12:07 PM

John, I forgot to ask, what does 6mm net in terms of magnification for your target scope?

 

I'm in southern California and we don't have the best skies but even here an average night in the suburbs when observing planets with the DL's 100mm f/9 I tend to work within the 150-200x range. Under better skies I setup the P/AT 130mm f/6 and top out at 260x. To use more magnification than this needs much darker skies and a 2 or more hour car trip out of the city where the M10" or C11" can do their best work. 

Post #3 above.  203x in a 6" f/8 apo.  Many times that's the highest useful power, due to seeing.


Edited by John Fitzgerald, 13 December 2019 - 12:07 PM.

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#18 YAOG

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Posted 13 December 2019 - 12:09 PM

Post #3 above.  203x in a 6" f/8 apo.  Many times that's the highest useful power, due to seeing.

Dooh! I knew that!

 

For planetary work 200x is sort of the usual upper limit here 12 miles from downtown Los Angeles which makes the 100mm class tubes so useful and handy. When it has been exceptionally still and transparent I've gone up to 300x but it is rare to have that level of quality sky here in my driveway. 


Edited by YAOG, 13 December 2019 - 12:20 PM.


#19 CollinofAlabama

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Posted 13 December 2019 - 12:55 PM

John Fitzgerald,

 

I forgot to mention that I am NOT a fan of the DeLites.  See this post.  I find them unable to render contrasting colorful double stars well (like Almach, Albireo, h3945, etc.) in smaller apertures.  Forgot to ask what size scope you're using, because this contrast issue seems to clear up with larger apertures, like 10" and above.  If you're using a smaller refractor, especially in the 100mm-range, buyer beware. Does this translate to the Delos?  Can't say it does, but equally I cannot say it does not.  Of course, you may not care about colorful doubles, either, so then it wouldn't matter, but if you do like colorful double stars (some of my favorites, personally), then you should be aware.  Rather fond of Delta Cygni, too, though, and in my 4" long tube achromat, can split the two nicely with the BCO 6mm.


Edited by CollinofAlabama, 13 December 2019 - 12:55 PM.

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#20 John Huntley

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Posted 13 December 2019 - 07:04 PM

My favourite 6mm for this task was the Baader Genuine Ortho 6mm. It was the eyepiece that first split Sirius for me. I prefer a little more observing comfort these days so I'd prefer a Vixen SLV 6mm which, when I compared them, matched the Baader GO 6mm in all ways performance-wise including making the Sirius split.

 

If you can find them the Astro Hutech 6mm HD ortho and the Fujiyama 6mm HD ortho provide an identical visual performance experience to the Baader GO 6mm.


Edited by John Huntley, 13 December 2019 - 07:04 PM.

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#21 Steve Cox

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Posted 13 December 2019 - 08:03 PM

I'll also throw in my vote too for the TV 3-6 zoom. But don't discount the 6mm Ethos it's a really good planetary too.
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#22 Jeff Morgan

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Posted 14 December 2019 - 12:54 AM

TMB Supermonos are amazing for such work.

 

A 6mm Brandon would also be excellent.


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#23 StarDust1

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Posted 14 December 2019 - 09:55 AM

Do the TMB supermonos work probably in fast F5 scopes?

#24 emilslomi

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Posted 14 December 2019 - 10:50 AM

Do the TMB supermonos work probably in fast F5 scopes?

Depends on how much of the FOV you want the be sharp. At F5, I guess only half of it will really be useful and only the center one third will be supper sharp.

 

Emil



#25 YAOG

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Posted 14 December 2019 - 11:06 AM

John Fitzgerald,

 

I forgot to mention that I am NOT a fan of the DeLites.  See this post.  I find them unable to render contrasting colorful double stars well (like Almach, Albireo, h3945, etc.) in smaller apertures.  Forgot to ask what size scope you're using, because this contrast issue seems to clear up with larger apertures, like 10" and above.  If you're using a smaller refractor, especially in the 100mm-range, buyer beware. Does this translate to the Delos?  Can't say it does, but equally I cannot say it does not.  Of course, you may not care about colorful doubles, either, so then it wouldn't matter, but if you do like colorful double stars (some of my favorites, personally), then you should be aware.  Rather fond of Delta Cygni, too, though, and in my 4" long tube achromat, can split the two nicely with the BCO 6mm.

Coelum,

 

I've never see what you are describing in a TeleVue Ethos, Delos or Delite eyepieces regardless of focal length in any scope regardless of aperture. 


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