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Eyepiece Recommendations for 90mm Refractor

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#1 Patrick

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Posted 13 January 2014 - 04:50 PM

Hi Gang,

I just acquired a new Stellarvue 90mm Raptor APO and am looking for eyepiece recommendations. The scope is an f/7 with a focal length of 630mm.

My eyepiece kit currently consists of a TV 31mm Nagler, 27mm Panoptic, 25mm TV Plossl, 20mm TV Plossl, and 9mm Burgess/TMB Planetary. I also have a 2x Powermate.

The 31 Nagler is awesome in the scope and the 9mm Burgess is pretty nice too. I'd like to get an eyepiece that would top out the scope at about 180x (0.5mm exit pupil) and have been looking at the Nagler 7mm or possible the Delos 8mm.

Can anyone explain to me the differences between the N7 and the D8 other than the focal length?

Any recommendations in the mid f/l eyepiece range? I also have an 8" EdgeHD that I use frequently.

Thanks!

Patricvk

#2 rockethead26

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Posted 13 January 2014 - 05:02 PM

Patrick,

I can't speak to the N7 or D8, but I will recommend the 7 XW which will provide the most comfortable view you've ever experienced. The 7 will give great views at 90x and then fit perfectly your upper end of 180x with the Powermate.

#3 Patrick

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Posted 13 January 2014 - 05:10 PM

The XW 7 sounds like an eyepiece worthy of consideration. Thanks!

Patrick

#4 FirstSight

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Posted 13 January 2014 - 08:07 PM

Can't go wrong with a 17T4 or 13T6 as your mid-power widefield. The 17T4 is 2" and has a much bigger eyelens than the 13T6 and better eye relief, but the 13T6 is a tack-sharp pleasure, best of class before the 100 degree Ethos came out.

I have an Ethos set and have also viewed through fellow club-members' Delos - my impression of the Delos is that optically it is extremely similar to the Ethos, except for having a 70 deg AFOV rather than 100 deg AFOV (which is the better experience is up to personal taste, but the Delos only costs apx. 60% of what the nearest comparable Ethos focal-lengths do.

#5 SAL

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Posted 13 January 2014 - 08:13 PM

Another vote for the Nagler 13T6. Congrats on the new SV Patrick. :waytogo:

#6 John Miele

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Posted 13 January 2014 - 08:51 PM

Hi Patrick,

I own the same scope and I love it. I agree 180x is probably near the upper end for planets but for double stars you can go quite a bit higher. I have split some doubles using a 2x barlow and a 5mm TMB giving 252x and the view was still clean...John

#7 Starman1

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Posted 13 January 2014 - 08:54 PM

Hi Gang,

I just acquired a new Stellarvue 90mm Raptor APO and am looking for eyepiece recommendations. The scope is an f/7 with a focal length of 630mm.

My eyepiece kit currently consists of a TV 31mm Nagler, 27mm Panoptic, 25mm TV Plossl, 20mm TV Plossl, and 9mm Burgess/TMB Planetary. I also have a 2x Powermate.

The 31 Nagler is awesome in the scope and the 9mm Burgess is pretty nice too. I'd like to get an eyepiece that would top out the scope at about 180x (0.5mm exit pupil) and have been looking at the Nagler 7mm or possible the Delos 8mm.

Can anyone explain to me the differences between the N7 and the D8 other than the focal length?

Any recommendations in the mid f/l eyepiece range? I also have an 8" Edge HD that I use frequently.

Thanks!

Patrick

A good 13-15mm mid power eyepiece would be great.

Differences between Nagler 7mm and Delos 8mm:
82 degree field (N) versus 72 degree field (D)
12mm eye relief (N) versus 20mm eye relief (D)
Nagler is a little cheaper now.
7 elements (N) versus (probably) 8 elements (D)
Both have vanishingly low angular magnification distortion.
Both are sharp to just at the edge of the field.
227g (N) versus 454g(D)
both are 1.25"
Flip up eyecup (N) versus uniquely-adjustable design (D)

#8 Patrick

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Posted 13 January 2014 - 10:55 PM

I can't speak to the N7 or D8, but I will recommend the 7 XW which will provide the most comfortable view you've ever experienced. The 7 will give great views at 90x and then fit perfectly your upper end of 180x with the Powermate.



I think I agree that I'm looking for a 7mm eyepiece. It seems like the right size for use with either the C8 or the Raptor.

Now, which one? There's a Naglar 7mm and Pentax XW 7mm. Any others to consider?

Patrick

#9 Patrick

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Posted 13 January 2014 - 11:04 PM

I own the same scope and I love it. I agree 180x is probably near the upper end for planets



Hi John,

Are you thinking an 8mm focal length eyepiece and 157.5x high end mag would be a more useful overall magnification? I'm not a big double star observer.

Patrick

#10 riverlaw

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Posted 14 January 2014 - 12:48 AM

I really enjoy the XWs line up in my 102mm refractor. Since you do not own a pentax I would recommend at least one!

#11 ibase

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Posted 14 January 2014 - 03:37 AM

Here's a visual comparison of the Nagler T6 and the Delos:

Posted Image
Nagler 5mm T6, Delos 6mm, ES-100 14mm

The most striking difference concerns relative sizes where the NT6 in its compact form trounces the big Delos and it goes with the weight as well, that makes for easier handling, storing and mounting of the Nagler T6, not to mention less awkward barlowing if that is an intended route. On optical performance, both are sharp/crisp EP's where the difference is less pronounced compared to the heft factor, and not having compared identical focal lengths, the impression is just that the Delos has a bit of a sharper & cleaner view, HD-like, but the bigger AFOV (82° Nagler vs 72° Delos) which for those who are partial to wider fields, may tilt the scale onto the Nagler end. Edge-correction is excellent in both lines, while tone is cooler on the Delos which also has a very generous eye relief of 20mm, more comfortable to use than the Nagler's 12mm ER. Eye lens on the Delos which could provide for a more immersive feel, is much bigger than Nagler's. The 5-6mm EP focal length is what I consider the sweet spot for the refractors in the stall (66mm, 80mm, 102mm & 152mm).

As for Delos vs Pentax XW, previously owned the Pentax XW 7mm, traded it for the Delos 6mm, and quite happy with the decision. Besides, the French mag had deemed that the decade-old Pentax XW was dethroned by the Delos in its lab test results pitting various top-notch EP's in the 10mm arena.

For mid-level magnification, there's nothing like the ES-100 14mm (or Ethos 13mm) with its majestic & expansive 100-degree views. Works great on the C8 scope too for dual-purpose. All just 2 cents.

Best,

#12 Jon Isaacs

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Posted 14 January 2014 - 05:01 AM

Patrick:

If you like the 9mm TMB Planetary, why not get a shorter focal length TMB? There is no doubt the Type 6 Naglers and the various other eyepieces mentioned are somewhat better but still...

With my short focal length refractors, I like to keep the Barlow out the picture for Planetary Viewing and only use the Barlow/Powermate for doubles.

Jon

#13 BillP

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Posted 14 January 2014 - 09:46 AM

Besides, the French mag had deemed that the decade-old Pentax XW was dethroned by the Delos in its lab test results pitting various top-notch EP's in the 10mm arena.


Interesting that the user reports out there seem to converge (IMO) on that it is a wash between the two, and no dethroning at all and more of a sharing of the throne. But perhaps the XW is not the best choice for lab-observing after all :lol:

#14 Patrick

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Posted 14 January 2014 - 09:58 AM

If you like the 9mm TMB Planetary, why not get a shorter focal length TMB?



I actually have an 8mm TMB Planetary that I'm not that happy with. I think there was a design change somewhere between the production runs of those two eyepieces and the 8 lost out. Anyway, if I spend $300-400 on an eyepiece, I want to be able to use it with the C8 as well as the Raptor. That means I will need to use my Powermate with the Raptor. A 3.5mm-4.0mm eyepiece will not work in the C8.

I'm also exploring the option of getting a 2.5x Powermate and a NT6 9mm. Or just getting the 2.5x Powermate and using it with the TMB 9mm. That combination would get me to 175x.

Patrick

#15 ibase

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Posted 14 January 2014 - 09:59 AM


Besides, the French mag had deemed that the decade-old Pentax XW was dethroned by the Delos in its lab test results pitting various top-notch EP's in the 10mm arena.




Interesting that the user reports out there seem to converge (IMO) on that it is a wash between the two, and no dethroning at all and more of a sharing of the throne. But perhaps the XW is not the best choice for lab-observing after all


Lol, well, not all observers; take the case of Alvin Huey, to whom many look out for when it comes to big scopes (he uses 22" up apertures) EP comparisons. Even before the French tests, he had been saying all along that Delos was better than Pentax XW for detecting faint objects, the difference becoming more apparent as the scope aperture rises. He also said that in his "dinky" 6" APO refractor, the difference was minimal, so you're right, the average astro enthusiast will hardly be able to tell the difference, thereby sustaining the it's a wash stance. If one can't tell the difference, the scope is simply not big enough. And there can only be one winner, and generally consumers want the winner, just look at all those age-old ads proclaiming that their product is the best, the winner, however miniscule or large the difference may be from the 2nd best, and such is the nature of marketing and capturing the consumer psyche. Yes, from the looks of it and given all these (both laboratory and big scopes field tests which both concur in conclusion), would say Delos had dethroned Pentax XW, but that's just IMHO.

Best,

#16 Patrick

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Posted 14 January 2014 - 10:02 AM

Any recommendations in the mid f/l eyepiece range? I also have an 8" Edge HD that I use frequently.



A good 13-15mm mid power eyepiece would be great.



Uh...yes, Don. But which one?!

I do appreciate your comments, btw! Thanks for the comparisons.

Patrick

#17 csrlice12

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Posted 14 January 2014 - 11:29 AM

for the mid-range, that ES100* 14mm is worth every penny, best of the bunch. BUT, if 100* isn't your cup of tea (it's not for everybody)....go for the 7XW....the quality difference between the XWs and the Delos isn't worth flipping a coin over. I do prefer the XW eyecup positioning system over the Delos though. And, IMHO, the XWs and Delos play well together.

#18 Starman1

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Posted 14 January 2014 - 11:31 AM

Any recommendations in the mid f/l eyepiece range? I also have an 8" Edge HD that I use frequently.



A good 13-15mm mid power eyepiece would be great.



Uh...yes, Don. But which one?!

I do appreciate your comments, btw! Thanks for the comparisons.

Patrick

Patrick,
As a vendor, I'm not supposed to pitch a particular line, but I suppose if I were ecumenical enough it might be allowed.
Here are some (only a few of many) good ones for you (I like them all):
Group A
Astro Tech AF70 13mm 70degree
Astro Tech Titan 15 70
Baader Planetarium Hyperion 13 68
Celestron Ultima LX 13 70
Celestron Luminos 15 82
Group B
Explore Scientific 82 Series 14 82
Explore Scientific 100 Series 14 100
Meade Xtreme Wide Angle 14 100
Nikon NAV-SW 14 72
Pentax SMC-XW 14 70
TeleVue Delos 14 72
TeleVue Nagler6 13 82
TeleVue Ethos 13 100
Vixen LVW Lanthanum ED Wide 13 65

Group A are the lower-priced bargains.
Group B are higher-priced and more highly reviewed.

#19 RAKing

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Posted 14 January 2014 - 04:53 PM

Another vote for the Nagler 13T6. Congrats on the new SV Patrick. :waytogo:


Here is another vote for the T6 Nagler series. :waytogo:

I have a small case filled with a 24mm Panoptic and four T6 Naglers (13, 9, 7, and 5mm) that I use with my 105mm Traveler. These are very small and light and they complement the Grab and Go nature of my scope.

All of the T6 Naglers Barlow very well (mine is the Zeiss 2x) and I have been up to 244x with my scope at times.

Congrats on the nice little SV!

Ron

#20 Starman81

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Posted 14 January 2014 - 06:04 PM

Patrick,

I can't speak to the N7 or D8, but I will recommend the 7 XW which will provide the most comfortable view you've ever experienced. The 7 will give great views at 90x and then fit perfectly your upper end of 180x with the Powermate.


I second the XW 7 recommendation. I use one for 71x in my 80mm f/6.25 refractor and also with the TV 2x and TV 2.5x Powermate for 143x and 179x. All 3 modes work wonderfully.

#21 t.r.

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Posted 14 January 2014 - 06:11 PM

I'm suprised no one has mentioned a TV Nag 3-6 zoom. It will get you the 180x you mention and then some. When I had my 90's, it was the only eyepiece I would take out many times for doing lunar/planetary/doubles. Works at a low 105x too for many DSO's.

#22 John Miele

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Posted 14 January 2014 - 09:00 PM

Patrick,

I also use a barlowed 8mm to get that power (157x) and Jupiter remains sharp and contrasty in good seeing. Although the image is beginning to dim a bit and floaters begin to come into play (for me). I think you could go higher in power and still get a sharp view but the dimming and floater issues will start to become more problamatic. My favorite way to view planets is with a pair of binoviewers. I hav ean old pair of Burgess BVs with 17mm wide angle EPs. I screwed the bottom part of a barlow lens to the end of the BV so I can achieve focus and the views of planets are wonderful. I think that setup is operating around 130x. But in a BV everything looks "larger" to me and there is still a lot of contrast in the view. AND no issues with floaters using two eyes. I really only use the really high powers (180x to 220x) on double stars...John

I own the same scope and I love it. I agree 180x is probably near the upper end for planets



Hi John,

Are you thinking an 8mm focal length eyepiece and 157.5x high end mag would be a more useful overall magnification? I'm not a big double star observer.

Patrick



#23 Jon Isaacs

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Posted 15 January 2014 - 05:20 AM

I actually have an 8mm TMB Planetary that I'm not that happy with. I think there was a design change somewhere between the production runs of those two eyepieces and the 8 lost out. Anyway, if I spend $300-400 on an eyepiece, I want to be able to use it with the C8 as well as the Raptor. That means I will need to use my Powermate with the Raptor. A 3.5mm-4.0mm eyepiece will not work in the C8.



Patrick:

My main concern is that if you like splitting close doubles, you will not have sufficient magnification unless you have an eyepiece in the 4mm range and Barlow it.

Jon

#24 Jon Isaacs

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Posted 15 January 2014 - 05:20 AM

I actually have an 8mm TMB Planetary that I'm not that happy with. I think there was a design change somewhere between the production runs of those two eyepieces and the 8 lost out. Anyway, if I spend $300-400 on an eyepiece, I want to be able to use it with the C8 as well as the Raptor. That means I will need to use my Powermate with the Raptor. A 3.5mm-4.0mm eyepiece will not work in the C8.



Patrick:

My main concern is that if you like splitting close doubles, you will not have sufficient magnification unless you have an eyepiece in the 4mm range and Barlow it.

Jon

#25 csrlice12

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Posted 15 January 2014 - 08:05 AM

Patrick,

I also use a barlowed 8mm to get that power (157x) and Jupiter remains sharp and contrasty in good seeing. Although the image is beginning to dim a bit and floaters begin to come into play (for me). I think you could go higher in power and still get a sharp view but the dimming and floater issues will start to become more problamatic. My favorite way to view planets is with a pair of binoviewers. I hav ean old pair of Burgess BVs with 17mm wide angle EPs. I screwed the bottom part of a barlow lens to the end of the BV so I can achieve focus and the views of planets are wonderful. I think that setup is operating around 130x. But in a BV everything looks "larger" to me and there is still a lot of contrast in the view. AND no issues with floaters using two eyes. I really only use the really high powers (180x to 220x) on double stars...John

I own the same scope and I love it. I agree 180x is probably near the upper end for planets



Hi John,

Are you thinking an 8mm focal length eyepiece and 157.5x high end mag would be a more useful overall magnification? I'm not a big double star observer.

Patrick


How do you like the Burgess binoviewer? Got a chance to get one for a good price.






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