43 replies to this topic

[SeattleScott]

Hallelujah.jpg

The view should be sharp. Now you pay the price of practically no ER, and somewhat narrow AFOV. Just depends on what is most important. 30 Euros means you can’t have it all. You have to prioritize what you want.

[EsaT]

..and on the planets you do not need to see the field stop and the "whole image" as you say.

But that small part of by modern standards already narrowish to start with view won't find planet easily.

Also rotation of this third rock from the Sun tries to continuously move target out of view.

That makes for lots of extra work.

 

Then there's the only celestial object looking visually like in images, our Moon,which isn't tiny target with all the details spread all over it.

[northernmike]

CrazyPanda had a series of posts where he spent considerable time and effort trying to fix the glare problems with the Goldline, taking the eyepiece apart, putting in materials, blackening edges, and ultimately failed to substantially improve the performance of the eyepiece on bright objects. He basically concluded the design is flawed and it cannot be made into a good planetary eyepiece.

It also is notorious for suffering from blackouts.

So the good eye relief is a plus, and wide AFOV adds more tracking time. But probably not accurate to call it an excellent planetary eyepiece unless you are talking specifically about its performance compared to some other 6mm eyepiece. Any eyepiece can be viewed as excellent as long as it isn’t being compared to something else.

Now I’m not saying it is a bad eyepiece. It’s super cheap, good ER and AFOV. If one prioritizes ER and AFOV over having the sharpest possible view, it can be a good choice.

Exactly Scott.In that price range and for a newbie who owns a dob for the first time , it's a good eyepiece for a starter, not an excellent , sorry.The goldline made me see my first targets like M31 , the Pleades and and the double star, Polaris.
I can honestly say that I'm still a newbie. I first started with the dob , upgrading to a dual speed focuser , Telrad raci finder etc... I'm now to the point of upgrading my EPs . I started with the ES 68° 24 mm(my favorite EP) second , I bought a used 14 mm 82° ES , also a used Meade 5.5 mm 82° for planetary. My next move is the 8.8mm ES and a good 2x barlow for astrophotography.

He had a 30 pound budget , and for that kind of money , the best choice is the 6mm svbony , better than the original "super plossl" that comes with the scope. I had fun with this EP , but now with the 5.5 Meade , wow! It's another world.

Edited by northernmike, 03 February 2025 - 01:23 PM.

[SeattleScott]

Agree, at the 30 euro price point, the 6mm SVBONY is worth considering, and possibly the best option out there.

[CarolinaBanker]

You will have a hard time using any more power than your 9mm will provide, 133X. I would suggest that you fill the gap with eyepieces around 12, 15, 20mm. Too many beginners are convinced that you need high magnification.

Well, for lunar/planetary you do, I routinely use around a .5 mm EP and go as high as 200x in a 4” achro.

[Jay_Reynolds_Freeman]

200x is not unreasonable for lunar and planetary work with 150 mm aperture in good seeing, though it will depend on which planet -- you might have better views of Jupiter and Saturn with less magnification.

 

What makes eyepieces expensive to manufacture is wide fields of view (requires bigger lenses and more of them), lots of pieces of glass, and fancy coatings, though market prices do not always precisely reflect these parameters. At f/8, all but the oldest designs will work fine. I would go with a simple design with modest field of view and few air/glass interfaces (less scattered light),perhaps an orthoscopic or a Plossl.

Edited by Jay_Reynolds_Freeman, 11 February 2025 - 01:08 AM.

[SeattleScott]

200x is not unreasonable for lunar and planetary work with 150 mm aperture in good seeing, though it will depend on which planet -- you might have better views of Jupiter and Saturn with less magnification.

What makes eyepieces expensive to manufacture is wide fields of view (requires bigger lenses and more of them), lots of pieces of glass, and fancy coatings, though market prices do not always precisely reflect these parameters. At f/8, all but the oldest designs will work fine. I would go with a simple design with modest field of view and few air/glass interfaces (less scattered light),perhaps an orthopedic or a Plossl.

Even better, an orthoscopic or a Plossl 😃

The problem can be, to get to 200x magnification, you need short focal lengths, which have tight eye relief in these designs. So on a budget, I like the vintage Parks Gold or Orion Ultrascopics, as they are sharp, and have pretty usable ER even in the short focal lengths.

[Jay_Reynolds_Freeman]

Even better, an orthoscopic or a Plossl

The problem can be, to get to 200x magnification, you need short focal lengths, which have tight eye relief in these designs. So on a budget, I like the vintage Parks Gold or Orion Ultrascopics, as they are sharp, and have pretty usable ER even in the short focal lengths.

Ah, the curse of the spelling corrector... Point taken about eye relief, but that is a tradeoff that is implicit in the "budget" part of this thread's title. I have been using short focal-length eyepieces with small eye relief since before units with long eye relief were available, and can attest that though it takes a little finesse and small head motions to use them, they can be used satisfactorily. One's mileage may vary if one needs to use glasses when observing.

[SeattleScott]

The pseudo Masuyamas go for around $60-70 so not much more than a good Plossl or Ortho. However they are only available used.

[Kuba_81]

Last week I was observing moon through barlowed GSO 9mm plossl. I felt a need for increasing the power so I purchased that tiny Svbony 6mm plossl for 21 euros which was the cheapest EP in entire store. Well, I'm impressed with the crisp views. Mars, Jupiter and moon are very sharp and detailed. The eye relief is acceptable - I stick the eye cup to my eyelid - just like with the binoculars. I haven't experienced any fogging. However, the FOV is narrow and everything is drifting away fast at x500. But I have to admit it, I got myself many times just gazing at the moon through this tiny cheapest eyepiece, panning across the terminator line with jaw dropped. I was then thinking to myself "I don't know where am I, but I don't care, this is awesome!".

[northernmike]

Last week I was observing moon through barlowed GSO 9mm plossl. I felt a need for increasing the power so I purchased that tiny Svbony 6mm plossl for 21 euros which was the cheapest EP in entire store. Well, I'm impressed with the crisp views. Mars, Jupiter and moon are very sharp and detailed. The eye relief is acceptable - I stick the eye cup to my eyelid - just like with the binoculars. I haven't experienced any fogging. However, the FOV is narrow and everything is drifting away fast at x500. But I have to admit it, I got myself many times just gazing at the moon through this tiny cheapest eyepiece, panning across the terminator line with jaw dropped. I was then thinking to myself "I don't know where am I, but I don't care, this is awesome!".

Was it the red line or the gold line?
The gold line is 66° and the red is 68° . With the 6mm , the extra 2° makes only a small difference but still.
I own a set of Svbony gold line and à set of red line by a unknown company but they are exactly like the Svbony the view is clear and I paid 14$ for the whole set,beleive it or not!
I could'nt pass on a deal like that. With my new Explore scientific EPs , it became my "guest" EPs , at that price , I don't care if they put their fingers on the glass and they still have a good clear view , they're not ''that cheap"
I highly recommend those as beginner EPs.

Edited by northernmike, 11 February 2025 - 06:41 AM.

[Kuba_81]

Was it the red line or the gold line?

Neither red nor the gold line, this one was 6mm from SV131 series.

[northernmike]

Neither red nor the gold line, this one was 6mm from SV131 series.

Ok , I found it on the svbony site.
48° AFOV , that is like looking into a straw, you don't have much viewing time I presume.

[vtornado]

A straw is about 5 degrees.  I measured it.

Edited by vtornado, 11 February 2025 - 11:43 AM.

[SeattleScott]

When buying such cheap eyepieces, you have to prioritize. You can't have it all. Do you want good eye relief and AFOV the most? Buy a red line or gold line. Sure, they are known for glare issues when viewing the Moon and planets, largely because of how the lenses are beveled, so it can't even be fixed by modifying the eyepiece. And they tend to have blackout issues. But you get good ER and AFOV.

 

Or, the 6mm Plossl can probably deliver sharper views without blackouts. You sacrifice eye relief, and the AFOV is snug. 

 

That's the reality at this price point. You can't have it all for under $30, so you just have to decide what you want most.

[vtornado]

You could play the lottery and try a 6mm TMB 58 degree planetary clone.

Edited by vtornado, 11 February 2025 - 03:40 PM.

[SeattleScott]

You could play the lottery and try a 6mm TMB 58 degree planetary clone.

Not a bad idea. They can be pretty good if you don't get a dud. Decent AFOV, pretty good ER, respectable contrast.

[ChristianG]

Hello all. 
 

For what it's worth, I have a bag of 4 mm and 6.3 mm so-called 'Plossl' (they are likely not actual Plossl designs). They came with telescopes. As posted above, their eye relief is so short that they are frustrating to use. If you have eyelashes for instance. I use them to make artificial stars. I would NOT recommend spending any money on those. 
 

The various 66 or 68 degree eyepieces that come in 6, 9, 15 and 20 mm are pretty much all the same. They have been around for years. I currently have the 'red' line ones, I had other series in the past. They are very good and the eye relief makes them comfortable to use, including the 6 mm. They perform well with longer f-ratios, but for planets the 6 and 9 mm are excellent in most telescopes. 
 

Personally, the shortest focal length 'Plossl' that I would consider usable is 15 mm. A 32 mm one however can be very useful, and I have a couple that are used often. 
 

Just my experience...

 

--Christian

[radiofm74]

My suggestion would be either Thomas' suggestion of a 15mm + a good Barlow, or getting a Vixen LV 6mm on the used market. They will be a little above your budget but still cheap (I find them for 50€ with ease), excellent optically, with a comfortable 20mm eye relief. Relatively small FOV, but that's no concern when viewing the planets.