14 replies to this topic

[tscherer]

I'm looking at the Explore Scientific 8.5mm 82deg LER and the SVBONY 68 deg 9mm, which look similar in specs but the ES costs 7x more. Is it that much better in overall quality? Or is it mostly because of the wider FOV?

 

Edit: this is for my 8" f/6 Dobs, focal length 1200.

Edited by tscherer, 19 June 2025 - 10:14 PM.

[Scope_hogger]

I own both ES and Svbony eyepieces, and it depends on your scope. If you own a long focal length scope, like a mak or SCT, I think Svbony would be good enough.

but anything shorter than that, and the edges if the FOV in the bonies will degrade in sharpness, colour and field-flatness.

In the long run, you'll be happier with the ES 8.5mm than with the 9mm bony, as better sharpness across the field of view and barely any false colour is, for me, at least, the better choice.

If you can afford it, take the ES

[Starman1]

Except the ES 8.5mm isn't a great eyepiece either:

 

spherical aberration none
coma none
astigmatism in field toward edge minimal
field curvature none
distortion type and amount pincushion--moderate
chromatic aberration--axial and lateral minimal
apparent field 82°
eye relief comfortable
light scatter control-in field bright planet reflections from eye to lens and back
light scatter control--outside field extremely poor
SAEP none noticed
CAEP minimal
Tint minimal--slightly warm
Vignetting none
Transmission good
thermal issues none
field stop in focus? average
contrast? excellent in center, average at edge
EOFB none
sharpness on axis good
sharpness 50% point in field good
sharpness edge good

comments Primary problem is unrestrained glare from bright
source outside the field.  It causes spikes and glare
in the field in linear spikes, loops, and a general
glow across the entire field.  The worst I've seen in
an eyepiece of any brand.
In field, a bright object like a planet or bright star causes a
glow to cover the entire field and I tracked it down
to reflection from the cornea to the eye lens and
back again.  This is ghosting but it is not reflections
between elements, though it could be from the
bottom of the eye lens elements.  The 8.8mm 82°
was not perfect, but it was a lot better in this regard.
Suggestion is to more effectively baffle the lower
elements in the eyepiece and to blacken any spacers
on both sides of the lowest elements to prevent
the reflections in the field.  Fix this problem and the
eyepiece would be significantly better.

 

Among the 8.5mm, 6.5mm, and 4.5mm 82° ES eyepieces, they get progressively worse as the focal length shortens,

The 8.5mm was the best of the three.  However, buy a used 8.8mm first.  It's a better eyepiece.

 

If ES fixed the light scatter problems in the 8.5mm, I would recommend it, because the rest of its characteristics are good.

If never used for Moon, planets, or bright stars, the 8.5mm is OK.  As a faint galaxies eyepiece, it would be just fine.

[Nautilus]

What telescopes will you be using the eyepiece with?

Find another brand eyepiece priced more than the kidney beaning Svbony and less than the ES.

The Svbony gold line is a better eyepiece than their redline version.

[SeattleScott]

The Goldline is just a rebadge of the Redline, so it is really just a question of price and cosmetic differences.

[Apnee44]

I have got the ES 8.5, as Don said above, it is definitely not a planetary eyepiece. But, quite nice for galaxies. If eye relief is not an issue, you can try to get an ES 8.8 instead.

[Nautilus]

The Goldline is just a rebadge of the Redline, so it is really just a question of price and cosmetic differences.

With the gold line, the FOV is 2 degrees less and the price is $2 less. 
 

[SeattleScott]

With the gold line, the FOV is 2 degrees less and the price is $2 less.

The AFOV is 66 for both. The advertised AFOV is two degrees different.

[MrsM75]

I don't have ES 8.5mm so I not know, BUT I had the Svbony 9mm 68 deg (I end up gave it away), the reason why is it gives me Kidney beans. If you search the site you will also see other people said they experience kidney beans with the 9mm and 6mm of the goldline and redline Svbony.

[Martinbruce]

I have the ES 8.8 and it has been one of my go to eyepieces that gets use every night. I use it with my AT115EDT, StellaMira 125ED, and the EVO 8. I have no complaints. Now, I don’t wear glasses and the eye relief has been good. You do get that “immersive” eye popping experience with the 82 degree FOV.  Cheers

[rlomond]

I have the ES 8.8 and use it with an 8 inch f6 dob. It's an excellent eyepiece.

[RichA]

Why does ES make an 8.8 and an 8.5, both with 82 deg fields?  Has one been discontinued?

[Starman1]

Why does ES make an 8.8 and an 8.5, both with 82 deg fields?  Has one been discontinued?

Yes, they discontinued the 8.8mm, 6.7mm, and 4.7mm in favor of the 8.5mm, 6.5mm, and 4.5mm.

They gained a little bit in eye relief (though not enough for glasses), but sacrificed optical quality to do so.

[Inkie]

I was very pleased with the ES 8.5 first time I used it...about three months ago or so...but it was only on Jupiter, which I thought was a pretty decent view.  I posted back then that I am happy to have this eyepiece.  I suppose I'll have to spend more time with it viewing when something like a waxing or waning Moon is very close to the optical axis and near the view.  

[Ernest_SPB]

I'm looking at the Explore Scientific 8.5mm 82deg LER and the SVBONY 68 deg 9mm, which look similar in specs...

The main difference in AFOV and image quality control over the field. So, I would not say the are "similar".