30 replies to this topic

[Mbinoc]

For anyone who picked up this orange stripe set of Aspheric eyepieces that come in "4mm /10mm /23mm" sets.

 

If you are unhappy with the performance of the 4mm in the set like I was, after watching a youtube video I saw that there is a barlow lens inside the aluminum base portion that could easily be removed.

 

If you unscrew the aluminum base of the eyepiece, the barlow will be found in this base portion, and could easily be rotated out. (Note: It is the only lens in the base portion, so you do not have to worry about messing anything up if you remove it).

 

I was originally unhappy with the eyepiece the way it came, but after removing this Barlow lens, I have found it to be very usable. Last night I compared it to a 9mm Meade MA eyepiece looking up at the moon, and found that it performed better.

 

The video I watched on youtube stated that with the Barlow removed, it turns into approximately a 8mm eyepiece.

 

 

 

If you are not happy with your 4mm Svbony Aspheric, try removing the Barlow and giving it another try. You could always screw the Barlow lens right back in if you still do not like it.

Edited by Mbinoc, 23 September 2020 - 01:19 PM.

[Shorty Barlow]

I have a feeling it is the 10mm version with an added Smyth lens. 

[Mbinoc]

It very well could be, I do not have the 10mm available to compare it too.

[Shorty Barlow]

 

The 10mm & 23mm are actually pretty good.

 

 

The 4mm is a bit of a 'spectroscope' though lol.

 

 

I think this is due to the barrel Smyth lens. You've probably improved the eyepiece vastly by removing it. 

[Terra Nova]

I’ve only had the 23mm IIRC. It was amazingly good considering the meager price.

[StarAlert]

I have an Edmund Astroscan coming in a few days and I have the 23mm and 10mm that came with a prior purchase. How do you think they'll work in the f4.25 Astroscan? I'm hoping the 23mm at 62^o will be good. 

[Hamlet]

I have the celestron 4mm plossl and it's dim, and it is quite uncomfortable to look through it having a 3mm lens. Would it be better to buy this 4mm svbony?

[Shorty Barlow]

I have the celestron 4mm plossl and it's dim, and it is quite uncomfortable to look through it having a 3mm lens. Would it be better to buy this 4mm svbony?

No.

[CeleNoptic]

I have an Edmund Astroscan coming in a few days and I have the 23mm and 10mm that came with a prior purchase. How do you think they'll work in the f4.25 Astroscan? I'm hoping the 23mm at 62^o will be good. 

 

IMO, at F/4.2 they both could be a disaster. I'll be happy if I'm wrong.

[Miranda2525]

IMO, at F/4.2 they both could be a disaster. I'll be happy if I'm wrong.

You won't be happy. I used to use a pair of the 23mm's in binoviewers, (F/12), they were both good. I tried one of them in my Orion 10" XTi F/4.7 and it was a complete disaster.

Edited by Miranda2525, 01 October 2020 - 09:26 PM.

[CeleNoptic]

You won't be happy. I used to use a pair of the 23mm's in binoviewers, (F/12), they were both good. I tried one of them in my Orion 10" XTi F/4.7 and it was a complete disaster.

 

I know. In my F/6 Dob the 23mm was good up to ~80% from center so I can easily imagine what it would be at F/4.2  ... the 4mm was just a funny toy 

[Hamlet]

No.

No?, could you explain why?, I don't like to stock the eye to the EP when I use the 4mm 

I have found this EP on aliexpress, I think they are fake meade ones https://www.aliexpre...3034668248.html

Attached Thumbnails

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Edited by Hamlet, 02 October 2020 - 10:39 AM.

[Shorty Barlow]

No?, could you explain why?, I don't like to stock the eye to the EP when I use the 4mm 

I have a lot of 4mm eyepieces, ranging from a tiny 4mm orthoscopic to a 4mm Tele Vue DeLite. The larger 4mm eyepieces are far more ergonomic and easy to use than the smaller ortho's and Plossls. However, they are mostly optically fine.

 

The 4mm SvBony/Meade/Vite plastic aspheric suffers from quite noticeable chromatic aberration in use. The 23mm and 10mm don't suffer particularly badly from this in my experience. I trialled the 4mm SvBony a couple of years ago in a direct comparison with a 4mm TS HR Planetary and a 4mm Astro Hutech orthoscopic. 

 

 

I used an f/6, 150mm Newtonian, and observed the Moon for several hours alternating between each eyepiece. The SvBony showed quite a bit of false colour. So I don't recommend it.

[Hamlet]

I see!... Maybe I should stay with the celestron 4mm

[Shorty Barlow]

I see!... Maybe I should stay with the celestron 4mm

https://www.teleskop...iverguetet.html

 

[Shorty Barlow]

No?, could you explain why?, I don't like to stock the eye to the EP when I use the 4mm 

I have found this EP on aliexpress, I think they are fake meade ones https://www.aliexpre...3034668248.html

They're not fake anything. They all come out of the same factory, almost certainly located in China.

[Miranda2525]

No?, could you explain why?, I don't like to stock the eye to the EP when I use the 4mm
I have found this EP on aliexpress, I think they are fake meade ones https://www.aliexpre...3034668248.html

The Meades were out after any of the others, (Svbony, etc).

[Bowlerhat]

They're not fake anything. They all come out of the same factory, almost certainly located in China.

 

Meade..celestron..sybony.. dancing all around.

[Astrojensen]

The smyth/barlow element in the 4mm is most likely just a single lens, just like it was in a 9mm Sky-Watcher LET eyepiece I took apart recently. On-axis, it's acceptable, but off-axis, it rapidly turns into a kaleidoscope, no matter the f/ratio of the scope. 

 

 

Clear skies!

Thomas, Denmark

[Shorty Barlow]

 

 

 

Meade..celestron..sybony.. dancing all around.

 

I heard a rumour a while ago that Synta had plans to bundle the 23mm and 10mm with some entry level Sky-Watcher and Celestron scopes.

 

I'm sceptical though.

[sunrag]

I was wondering why the 4mm ep was taller than the 10mm ep. I got them mixed up all the time.

Thanks for the tip Mbinoc!

[Mbinoc]

Yes. I never claimed the 4mm eye piece would be great with the lens removed.

 

But by removing the extra barrel placed 4mm lens in this series of eye pieces, you can at the very least turn a junk 4mm eye piece from something I considered absolute garbage, into one that is usable. That was the intent of this post.

 

I would be very interested in hearing back from anyone who has the complete set, and could verify if the 4mm is the same as the 10mm once the lens is removed?

 

When I first purchased this set, I ordered a complete three piece set from china, and once the package arrived, I was disappointed to only receive the 4mm. I contacted the seller, and he refunded my money completely and apologized personally for the mistake, and asked me to not hold this mistake against him, and then left me a positive ebay buyer  review. I then returned the favor with a positive review,

 

To be nice, I took him at his word, and then gave him a 2nd chance and ordered a single 23mm which is the only one I really wanted. I ordered it from the same seller and the package arrived on time and with the correct eye piece.

 

----------------------------------------

 

Maybe I'm just a sucker, but the first guy I ordered from told me any mistakes he makes comes out of his own paycheck. When I ordered the 2nd eyepiece from the same seller, I also sent a note that stated the excellent customer service I received on the first order, and said this is why you got a 2nd order from me.

Edited by Mbinoc, 04 October 2020 - 06:43 PM.

[Bowlerhat]

I heard a rumour a while ago that Synta had plans to bundle the 23mm and 10mm with some entry level Sky-Watcher and Celestron scopes.

 

I'm sceptical though.

Hmm, I haven't compared them in detail with super-10/25 plossls, but the 23mm seems to have favorable reviews. I hope they don't replace the 4 element silver plossls with it though.

 

Maybe they'll follow meade and just sell it as an upgrade kit too?

[Jimmy462]

The smyth/barlow element in the 4mm is most likely just a single lens, just like it was in a 9mm Sky-Watcher LET eyepiece I took apart recently. On-axis, it's acceptable, but off-axis, it rapidly turns into a kaleidoscope, no matter the f/ratio of the scope. 

 

 

Clear skies!

Thomas, Denmark

My experience, too, with a 4mm Vite, though I would not necessarily go so far as to qualify the off-axis view as kaleidoscopic.

 

I've been testing a Lunt 102 f/7 the past few weeks and did several high power runs with the scope using 5, 4, and 3mm Delites, 4.8mm Original and 3.5mm Type 6 Nagler, 3.2mm AstroTech Paradigm, and (for fun, just to see what it could do) the 4mm Vite using the moon, Jupiter, Saturn and Mars as my bench-test targets, and the Vite 4mm, while clearly not in the same league of visual performance as any of the other eyepieces, did provide its own detailed and competent views in the center 50% of the field.

 

My copy I'd rate it as "acceptable in-a-pinch (read: break glass in case of emergency)" for planet viewing (keeping targets in the, um, sweet center zone) and, due to its poor chromatic edge performance, "barely acceptable" for lunar viewing.

 

Now, I have to say...I truly do not wish/desire to trash any optic if it can provide at least minimal-though-still-representative views of its "intended-targets design". I say this as I started my viewing experiences way back in the mid-60s with nothing more than some no-name WWII-era binoculars my Dad had laying around...those early views sparked the fire. This led to my first real telescope, a 60mm Lafayette Electronics-purchased 20-60x scope that uses two small metal peepholes for a finder (I still have this scope!), followed a few short years later with a paper-route funded Criterion 4.25" Newtonian with some A.R. eyepieces and sliding-element Barlow (the optics of which still survive). My point being, none of this equipment provided views comparable to a ubiquitous 102 f/7 (and TV EPs) like the one I've been testing...but they all worked for their "intended-targets design". Enough to spark a flame and sustain it...and, i that regard, the, um, "lowly" 4mm Vite is far from trash and more-than-enough to spark its own fires.

 

[Bowlerhat]

I have the celestron 4mm plossl and it's dim, and it is quite uncomfortable to look through it having a 3mm lens. Would it be better to buy this 4mm svbony?

Hi-res: https://imgur.com/a/u2UwAty

 

Is this the normal 4mm plossl? I did a comparo before between the two. The celestron fov is tight, but it's sharp on axis- although it's uncomfortable to use (I use glasses). Svbony lens diameter is much wider than celestron. Maybe I'll do a comparo with some 4mm orthos, could be interesting.

 

Here's an interesting report of celestron 4mm.

https://m-lambda.blo.../p/amazing.html