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Svbony 66-degree Long Eye Relief

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94 replies to this topic

#1 orlyandico

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Posted 14 May 2018 - 04:35 AM

These are around $25 a pop on ebay.

 

Anyone know if these have been rebranded? I bought two 6mm's as cheap BV eyepieces. I have nothing to compare them to but they seemed more pleasant than Vixen LV's (maybe it's just the wider field).

 

Edit: hmm, these seem to be Orion Expanse clones. I don't have any other 6mm's to try them against (have a 4mm Vixen LV and 9mm DeLite).


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#2 Joe1950

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Posted 14 May 2018 - 05:19 AM

They are clones of Orion Expanse. Also a couple other brands. They are found in 6, 9, 15 and 20 mm FL, and about 66 degree field. They are good. I like them. Not TeleVue quality, of course, but they are good with the mid to long Focal ratio scopes. I put flock paper on the inside of the 6mm just to be sure to keep any scatter or reflections down. Don’t know if it is needed, though.

 

Just got the 15mm with red trim. Nice and all metal. Good feel.


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#3 Adun

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Posted 14 May 2018 - 06:16 AM

These "good line" are expanse clones. I got the set for $84 from here.

They work very well on my mak, and on my F10 SCT, but they struggle in my F4.7 dob (induced astigmatism).

The 9 and 6 have an internal barlow, which is how they get the nice eye relief. The 9mm is the best of the set, followed by the 6mm, then the 20mm.

The ones with gold lines have anodized barrels and good reflection control (no need to "flock" anything).

I see there are new models with red lines and chromed barrels. I don't think those are the same (at least on scatter/reflections they can't be). I recommend the gold lined ones better, and for F8+ scopes only. 


Edited by Adun, 14 May 2018 - 06:21 AM.

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#4 Joe1950

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Posted 14 May 2018 - 07:46 AM

They are all the same inside with the outside colors and trim being different. I have a 6mm with a gold band and a 15mm with a red band. The red band have an excellent flat inside with no reflection seen at any angle. 

 

And if one wants to flock an eyepiece for greater control, maybe it is a good idea. There were some complaints about light reflections mentioned in the original Orion Expanse 6mm a while back. 

 

The red band have anodized barrels also - same thing - just look different on the outside. Why would the manufacturer go through all the trouble to redesign the inside and basic structure of an eyepiece they just make a little different on the outside with a different name on it. Gold band, red band, ALL THE SAME!


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#5 Adun

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Posted 14 May 2018 - 07:08 PM

Gold band, red band, ALL THE SAME!

 

zc4oa5R.gif


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#6 nhyone

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Posted 15 May 2018 - 09:14 AM

Also a rebrand of Agena Enhanced Wide Angle (EWA) at US$45 a piece.

At $20+ and with decent reputation for the 6mm and 9mm eyepieces, it is really hard to consider other cheap 60-ish degree eyepieces...

I had in mind the X-Cel LX 7mm (actually 6.5mm) and 9mm EP. Now I'm reconsidering.

Edited by nhyone, 15 May 2018 - 09:17 AM.

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#7 Shneor

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Posted 16 May 2018 - 01:10 AM

The 6 and 9 works just fine at f/4.5


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#8 Jon Isaacs

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Posted 16 May 2018 - 02:19 AM

The 6 mm and the 9 mm versions i have owned exhibited the brightened edge that has become known as Edge of Field Brightening.  They were about the first negative - positive eyepieces that were affordable.  I used to say that the 9 mm Expanse type eyepieces were the closest thing to a 9 mm Nagler you could find for $40.  A couple of tidbits:

 

- I drift timed the field of view of the 9 mm.  It equated to an effective AFoV of 70.5°…

 

- Antares sold a 8.7 mm 70° eyepiece that seemed to have the same optics . One Saturday i was fooling around with the Antares and discovered it was just a generic 9 mm Expanse with an aluminum cover glued in place. .

 

4487249-Antares W70a.jpg
 
As you can see , my 9 mm got a lot of use .
 
Jon

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#9 Jon Isaacs

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Posted 16 May 2018 - 07:28 AM

They work very well on my mak, and on my F10 SCT, but they struggle in my F4.7 dob (induced astigmatism).

The 9 and 6 have an internal barlow, which is how they get the nice eye relief. The 9mm is the best of the set, followed by the 6mm, then the 20mm.

 

As Shneor said,  the 6mm and 9mm works quite well in a fast scope , because of the "internal Barlow.". Technically its a Smyth lens and "Barlow-like" that is likely optimized to match the magnifying section's optics. 

 

One interesting tidbit about these eyepieces is that they are modular with interchangeable pieces , the front barrel , the body which contains no optics and the rear section with the magnifying positive section.  This also true of the 15mm but not the 20mm. 

 

They're also mix and match with the TMB planetary eyepieces .  Generally i found that they work best as they were made , the right pieces make the best views .

 

Jon


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#10 howardcano

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Posted 16 May 2018 - 11:25 AM

I had the Agena version and a generic direct-from-China version with the black painted barrel.  Unfortunately they hadn't allowed for the fact that the paint added to the barrel diameter, and it didn't fit in several diagonals and focusers.  A few minutes with a fine file fixed that.

 

The coatings looked better on the Agena, but performance of the generic was close enough, so I sold the Agena.

 

I also pressed a rubber O-ring into the barrel to reduce the field stop to about 55 degrees AFOV, since the edges were blurry at f/6.  So now it's like a Plossl but with better eye relief.  Plus it handles a Barlow with no vignetting!

 

Now I'm curious enough to try the 6mm.


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#11 tony_spina

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Posted 16 May 2018 - 12:47 PM

On the 9mm and 6mm clones that I have I flocked the inside to reduce reflections significantly. Easy fix with some craft store 1mm thick black foam cut to size from a sheets sold at the craft store. 

 

I use these in my ST80 f/5 as quick grab and go.  They even Barlow very well to give me an effective 3mm and 4.5mm.  Useful on the moon and planets, and double stars when all I have is this little scope with me when away from home

 

May consider getting the 15mm, but not sure if it will work well at f5


Edited by tony_spina, 16 May 2018 - 12:48 PM.

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#12 nhyone

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Posted 18 May 2018 - 01:57 AM

I find it interesting that for such a cheap eyepiece whose selling point is presumably its ultra low price, Svbony still finds the need to mark up its FOV to 68 degrees.

I bought a no-brand version (not even Svbony!) of the 6mm and 9mm EP -- going by the forummers' recommendation -- and got them yesterday. The large FOV and long eye relief are nice compared to the other cheap EPs I have in their range.

Quality-wise, I can't tell. So far, I've only viewed Jupiter on-axis, where all my eyepieces seem to perform identically, from ES 82, Ortho to my stock Kellner.
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#13 Jon Isaacs

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Posted 18 May 2018 - 05:47 AM

May consider getting the 15mm, but not sure if it will work well at f5

 

 

I had the 15mm (and the 20mm) 15 years ago when these eyepieces were first introduced.  To my eye, it appear to be essentially an Erfle,  You would need to be quite forgiving of astigmatism to find it acceptable at F/5.

 

Jon


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#14 nhyone

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Posted 18 May 2018 - 07:41 AM

I find it interesting that for such a cheap eyepiece whose selling point is presumably its ultra low price, Svbony still finds the need to mark up its FOV to 68 degrees.

Oops, I think I'm wrong. The 66 and 68 degrees EPs are different.

 

The 68 EPs have 5/3 lens layout. Eye relief is not stated. Code = YZ-3110[3-6].

 

The 66 EPs are, 6mm = 5/3, 9mm = 6/4, 15mm = 4/3, 20mm = 5/3. Code = YZ-302xx (06, 09, 15, 20).


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#15 Joe1950

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Posted 18 May 2018 - 07:59 AM

I have the 15mm Svbony (how is this pronounced?) with the red trim! Very classy! All metal too. I'm using it for medium power, 127X, with an f/15 scope, so I expect it will work well.


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#16 Adun

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Posted 18 May 2018 - 01:02 PM

I have the 15mm Svbony (how is this pronounced?) with the red trim! Very classy! All metal too. I'm using it for medium power, 127X, with an f/15 scope, so I expect it will work well.

 

While the 15mm is allegedly the worst of the lot (and I can attest it's not as good as the 9mm), mine is still holding on to the slot in both my "main"  and my "travel/outreach" sets:

 

Eyepiece collection

Top: main set, bottom: travel set

 

The thing is, at this FL (~14mm to ~17mm) I've found it harder to find a ~$100 "good enough", well corrected eyepiece that's worth the upgrade from the expanse. There are lots of accounts of eyepieces with field curvature, poor off axis performance at this FL, which combined with their higher prices made me just stay put with the 15mm. It's not perfect off axis but I like it's contrast and transmission. Given my scopes focal lengths (450mm to 1200mm) I don't use it for planets but for open clusters mostly, and for that it's good enough.


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#17 Joe1950

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Posted 18 May 2018 - 04:07 PM

I agree. At 127x I may use it on the moon at times or a low power planetary view. I usually start at about 150 with the planets and move up if seeing permits. Having an expensive EP at this FL is not worth the investment to me either - if I had the coin! lol.gif

 

So for the price, it does what I need - and that red racing stripe is the cats meow! 


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#18 nhyone

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Posted 20 May 2018 - 06:49 AM

I have the 15mm Svbony (how is this pronounced?) with the red trim!

Is it 68 instead of 66 degrees?

Based on my finding, the optical formula has changed for 9mm (from 6/4 to 5/3, likely worse) and 15mm (from 4/3 to 5/3, likely better).

The eye relief is 17-20mm, but not stated by eyepiece.
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#19 nhyone

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Posted 04 June 2018 - 05:15 AM

It's mentioned in other threads, but not here: the 6mm and 9mm EP kidney beans very easily, especially the latter! I did not realize that at first because I used them on Jupiter only. No problem on-axis, but it is something to watch out if you want the whole field.
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#20 howardcano

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Posted 04 June 2018 - 06:28 AM

I recently got the 6mm to fill out my "B-team" of eyepieces.  The eye relief is pretty good, and sharpness is acceptable for the price.  It works okay on Jupiter, but floods badly on lunar views despite the flocking I added internally.

 

I'm not finding any kidney bean effect, but my glasses probably keep me from getting close enough to see it.


Edited by howardcano, 04 June 2018 - 06:29 AM.

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#21 Joe1950

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Posted 04 June 2018 - 09:06 AM

If you want to know how an eyepiece manages light, look at the moon and sweep off to the side also. 

 

I had an eyepiece, 5mm FL, that had a huge flare of light at certain positions pointed at the moon. It was very annoying and made looking at the moon difficult at certain orientations.

 

Tried everything - flocking the tube, additional stops inside the tube...

 

Finally, what worked was to flock the retaining ring of the forward Smyth lens and the barrel area just after the retaining ring.

 

 

That worked well. Plus, in order to avoid any vignetting caused by the addition of the flocking material, I used Edmund Optics flocking, which a group of us found to be the thinnest available. No light reduction was noticed except for the flaring.

 

But sometimes glare and reflections take some investigating to figure out where the issue is.


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#22 Jaimo!

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Posted 04 June 2018 - 05:54 PM

I had the 15mm (and the 20mm) 15 years ago when these eyepieces were first introduced.  To my eye, it appear to be essentially an Erfle,  You would need to be quite forgiving of astigmatism to find it acceptable at F/5.

 

Jon

I have taken a 20mm apart...  More of a Konig derivative.

 

20mm Orion Expanse.jpg

 

I typically pick these up and give to friends who are just starting, they compliment and sometimes are an upgrade to the eyepieces that came with their scope.  If you were interested, you can pick up a 10 pack of the 9mm...  All and all they are a great value eyepiece for someone starting out or on a budget with a slower scope.

 

Jaimo!


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#23 Edwin

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Posted 05 June 2018 - 10:41 AM

Just ordered yesterday a set of 6, 9 and 20 mm of these on Aliexpress to replace the eyepieces that came with my Celestron Travelscope 70. I'm not taking my Panoptics and Naglers with me on holiday, so hopefully these relative cheap eyepieces will do nice. Mine are Celestron-branded, by the way (Ultra Wide 66), with chrome barrels and a golden ring.


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#24 Jaimo!

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Posted 05 June 2018 - 08:12 PM

Why would you not take your Pans and Naglers on holiday?  They have worked so hard all year.


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#25 Adun

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Posted 08 June 2018 - 10:05 AM

Just ordered yesterday a set of 6, 9 and 20 mm of these on Aliexpress to replace the eyepieces that came with my Celestron Travelscope 70. I'm not taking my Panoptics and Naglers with me on holiday, so hopefully these relative cheap eyepieces will do nice.

 

They will.

 

I took mine with my 80mm F4.4 travel refractor, to a remote beach. I really liked how they behaved, even the 20mm.

 

 

Why would you not take your Pans and Naglers on holiday?  They have worked so hard all year.

 

lol.gif

 

I'm assuming it was either because of weight, or for protecting the Naglers. I know I was afraid of sand and salty humid air when I took my expanses (instead of my UWAs) to the beach. Although... I've thought about that, and I've concluded that life's too short. Next time I travel I'm taking my "good" eyepieces. 


Edited by Adun, 08 June 2018 - 10:06 AM.

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