31 replies to this topic

[Kruegon]

Over the past few years, I have found the need to wear glasses. I only require them for close view and reading. Not required for walking, driving, or anything else. I do need them to read my hand controller. Putting them on and taking them off, constantly, during viewing is a serious pain. I am using budget eyepieces (SVBONY basic plossl and Orion Sirius Plossl) and they just do not provide the eye relief to leave my glasses on. 

 

Can anyone suggest a brand of budget EP that has a fair eye relief so I can use my glasses? I am in no rush, so ordering from China is acceptable. AliExpress and I are old friends. I'd prefer to stay in the $50.00 and below per EP, if possible. Oh, and green coating is fine, but my eyes like the blue coating better. I don't feel as strong of a strain on the eyes with the blue. Unfortunately, they seem to be the more rare incarnations on most EP brands.

 

I do have a Celestron 40mm (appears to be a rebranded GSO) that has an incredible view for the price, but still lacks the eye relief. My "other" Celestron 40mm is the unbranded SVBONY type and it has a horrible kidney bean in it, almost to the point of unusable. 

[EsaT]

No such brand because eye relief is feature of particular design.

Avoid Plössls or really anything usually cheap except in longer focal length:

Old simple eyepiece designs have eye relief in fixed ratio to focal length. (little over 2/3rd for Plössl)

 

6mm and especially 9mm Svbony "red lines" (better external finish/design than in gold line) would be good for shoestring budget.

20mm and especially 15mm aren't good except for slow long focal ratio telescopes and are more for like Maksutovs:

https://telescopicwa...line-eyepieces/

 

Also unless it's some EOL'ed/not sold anymore model, both 40mm Celestrons have lots of eye relief... In fact toward harder to keep eye at right distance from eyepiece long.

[scout]

Can anyone suggest a brand of budget EP that has a fair eye relief so I can use my glasses? I am in no rush, so ordering from China is acceptable. AliExpress and I are old friends. I'd prefer to stay in the $50.00 and below per EP, if possible.

You'll probably need 20mm of eye relief to wear glasses, which is difficult to find for your $50 budget limit. The SvBony 66°/68° redband and goldband eyepieces have comfortable eye relief and cost $20-$40 each depending on the sale, but I'm not sure if the 17mm eye relief is enough for you. They're also available as Orion Expanse and other lines, but the SvBony brand is usually cheapest. I have the 6mm and 20mm and they give nice bright images for the price.

[havasman]

As above, very limited selection at your price point and maybe none at shorter focal lengths. But

 

GSO 25mm Plossl            22mm eye relief           $30.95 at Agena

Astro-Tech 19mm PF        19mm ER                     $40 at Astronomics

 

It's the design more than the maker that provides ER. 

[SeattleScott]

I don’t know of any $50 eyepieces that have enough ER for most glasses users to see the whole view, other than Plossls above around 25mm.

TMB Planetary, Astrotech Paradigm, SVBONY gold/red lines, they have pretty good ER that will allow seeing most of the view with glasses. Possibly the whole view if you press in close. Typically 16-20mm of ER is required to see the whole view with glasses, depending on your glasses and your face. Most of these that I mentioned are typically around 13-15mm. Unfortunately, under $50 in price, you can pretty much throw advertised specs out the window. You will be doing good if it is actually the correct focal length. So I wouldn’t fret that maybe Gold Lines are 16mm ER while Red Lines are 14mm or whatever the advertised specs say. Basically any of these will be nearly enough eye relief for most people to see the whole view with glasses (without cramming in and pressing your glasses against the eyecup).

[gene 4181]

 When  I absolutely need the eye relief for  visitor observer's ,I get out the Baader  Hyperions  , not  cheap  but  very decent considering  their cost  and the  t Ring and abillity to morph to other FLs.

[Kruegon]

That info is a start! And yes, I would like to keep it lower priced for now, but doesn't mean it has to stay quite that low. I am building on a budget. Recently, I have acquired scopes that have better resolve than my EPs. Previously, my EPs were equal to or better than the telescope's ability to resolve. 

 

Busy season will hit soon and I will have OT money for EPs. 

 

EsaT: You stated "longer focal lengths". That brings up a question about something I saw earlier. Generally speaking, the shorter the FL, the shorter the EP and the smaller the external lens. I was looking at the offerings from Astromania, and they have some rather small FL EPs with unusually long bodies and unusually large external lenses. In all fairness, they are listed as planetary EPs. They all say 16mm eye relief. This is definitely longer than the short FL EPs I have now, but not as long as what scout was suggesting at 20mm. My 6.3mm requires my eye to almost touch the lens. Just wondering if this "might" be a move in the right direction. 

 

https://astromaniaop...ariantsId=10002

 

And what makes an EP a "planetary" EP? Does that mean I wouldn't want to use them for DSOs?

[astropgr]

Any eyepiece can benefit from extra eye relief with a Barlow since it increases the eye relief. 

[SeattleScott]

"Planetary eyepiece" really just typically means the AFOV is less than 60 degrees. So it isn't particularly good for framing deep space objects, so they advertise it as a planetary eyepiece instead. Really, just think of Planetary = narrow AFOV.

 

Yes the eye relief is spec'd at 16mm which is borderline. But that 25mm GSO Plossl someone listed as 22mm ER is really 17.5mm ER. So basically you really don't know what the ER is, other than it is most likely a touch less than 16mm. Honestly, there was a recent discussion about these eyepieces where users were reporting getting the wrong focal length eyepiece. It was labeled as the focal length they ordered, but the eyepiece was actually a different focal length. So that tells you how much you can trust their advertised specs. Really, people talk about the QC being all over the map with these particular eyepieces. Yes, you get decently wide eyepieces with pretty good eye relief, maybe even about enough for glasses, for like $20 or whatever. But there is no free lunch. At that price point, there is almost less than zero quality control. You could get a good one. You might not. You just really don't know what you are getting until it arrives and you can put it through its paces.

 

Scott

[TOMDEY]

Wearing your reading glasses at the telescope is very non-optimum. This is something other geriatric presbyopes accept and deal with... just by taking the glasses off for viewing. Rather than buying new eyepieces --- why not just get a lanyard for $10?   Tom

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[Kruegon]

 When  I absolutely need the eye relief for  visitor observer's ,I get out the Baader  Hyperions  , not  cheap  but  very decent considering  their cost  and the  t Ring and abillity to morph to other FLs.

Holy.... You are correct. Not cheap. But at least they are not TeleVue or Explore Scientific priced. What do you mean by "morph to other FLs."?

 

And I admit, the 1.25/2 barrels are a nice feature. My Mak is 1.25, but my dob and two newts are either/or. I have considered doing the SCT external focuser upgrade to my Mak. That would give me 2" for it as well. Mostly with my older hands, focusing a single speed can be iffy. I have actually considered taking a saw to my smallest newt and cutting a 2" hole in it for a dual speed crayford.

 

I wonder if any of the Astro society members have some I can test out. Not the price range I want, but possible future purchase. Especially if I can find some used at a lower cost.

[Kruegon]

Any eyepiece can benefit from extra eye relief with a Barlow since it increases the eye relief. 

I have always been advised to limit the use of a barlow for DSOs. I was taught that every piece of glass you add between you and the object will reduce the apparent magnitude within the view. So... I have tried to not use a barlow unless I have no other choice. Please don't tell me this was a waste of resources I could have employed. My telescope knowledge is considerably larger than my EP knowledge, at this point.

[astroclint]

You could get a 15mm eyepiece here it has a 62 degree field of view it also has 20mm of eye relief.

https://www.aliexpre...ler|query_from:

Edited by astroclint, 12 April 2024 - 05:58 PM.

[SeattleScott]

I have always been advised to limit the use of a barlow for DSOs. I was taught that every piece of glass you add between you and the object will reduce the apparent magnitude within the view. So... I have tried to not use a barlow unless I have no other choice. Please don't tell me this was a waste of resources I could have employed. My telescope knowledge is considerably larger than my EP knowledge, at this point.

This is good advice. If you have a <$20 barlow.

 

For a quality barlow, a couple extra elements makes very little difference. This is the type of thing for people to argue about barlowing a Takahashi Abbie Ortho or TPL versus using a short focal length Delos or Morpheus. You are talking about <$50 eyepieces. A couple extra quality lenses won't have anywhere near the detrimental effect on the view as using these cheap eyepieces. 

[gene 4181]

 I'm not so sure I agree with that , a  good barlow disappears in use like my TV 2x.   With todays modern coatings and applications  you're seeeing so many  multiple element  and set / groups  and its hard to discern  the extra elements into a darker view ......JMO and what others  with more knowledge base than me have mentioned     

[EsaT]

EsaT: You stated "longer focal lengths". That brings up a question about something I saw earlier. Generally speaking, the shorter the FL, the shorter the EP and the smaller the external lens. I was looking at the offerings from Astromania, and they have some rather small FL EPs with unusually long bodies and unusually large external lenses. In all fairness, they are listed as planetary EPs. They all say 16mm eye relief. This is definitely longer than the short FL EPs I have now, but not as long as what scout was suggesting at 20mm. My 6.3mm requires my eye to almost touch the lens. Just wondering if this "might" be a move in the right direction. 

 

https://astromaniaop...ariantsId=10002

 

And what makes an EP a "planetary" EP? Does that mean I wouldn't want to use them for DSOs?

Instead of just scaling design and decreasing focal length shorter, newer eyepiece designs use varying optical designs for different focal lengths to "decouple" eye relief from focal length.

And shorter focal length eyepieces are functionally like combined Barlow and longer focal length eyepiece.

It's similar layout as in camera "retrofocus" lenses when needing to project image farther than focal length:

https://www.lensrent...nealogy-part-2/

With shorter and shorter focal length needing stronger Barlow to keep up the long eye relief making physical size increase from medium to the shortest focal length models:

https://assets.baade...yepiece-740.jpg

(Morpheus is Baader's high quality line and close to TeleVue quality)

 

6.3 mm Plössl has maybe ~4½ mm of eye relief and that's measured not from the physically topmost part of the eyepiece, but from the eye lens. (topmost lens)

So you obviously have to cram head very close to eyepiece to get pupil close enough.

That also means there are eyepieces in which actual useful eye relief is significantly smaller than advertised.

For example Explore Scientifics have eye lens ~2 mm below top of the "shell" and Long Perng 80 UWAs have thick hard rubber "cup" eating 5+ mm of eye relief.

 

 

"Planetary" is mostly marketing term to make narrow/medium AFOV eyepieces sound better.

[Kruegon]

Seems there's even more to learn about EPs than telescopes. Coming into this hobby, I only knew about Refractors and Reflectors. I was so ignorant, I actually thought the refractor was the superior design. Of course, I have since learned of all the other designs and that each has a purpose different than the next. A place for all of them. EPs were just what allowed me to see the images and created the magnification. H20, H12.5, and SR4. Pfft, who needed anything else. Then I was introduced to the Plossl. Wow. And then some jack-leg showed me a Televue Nagler. Oh and he waited until I wanted one to tell me they are several hundred dollars, lol. I felt like the dog havinjg the steak dangled in front of it. I still don't understand all the lens designs, yet. I knew there were Plossls, then found Super Plossls (really?), then found out there are cheap Plossls and quality Plossls. Now I am being told about Hyperions and Expanses and who knows what else.

 

What I have discovered, that is most important, is that what you pay for is not always what you get. Good EPs cost real money, but a high price tag doesn't mean high quality views. And a lower price tag, doesn't always mean low quality. To my eyes, my Sirius Plossls have a very clean view. And the Clestron 40mm that looks like a rebranded GSO is very clean and crisp. If they had the eye relief, I think the GSO Superviews would fill my personal need, and stay within a budget I can easily handle.

 

Would any of you agree, that with a budget, a quality barlow is my best attempt for eye relief? Does an ED barlow make enough difference for the price? And if I go this route, would the recommended Hyperions be the best balance between price/performance/ER? If you disagree, What else would you recommend.

 

I cannot thank you all enough. This has been a rather eye opening discussion. Feel free to pour as much knowledge into this as you want. I welcome it all. Seems I will have years of EP study ahead, and a lot of savings.....

[Starman1]

OK, you're on the steep part of the learning curve:

https://www.cloudyni...ce-aberrations/

 

Then, your choices:

https://www.cloudyni...ide/?p=12473522

 

Price-wise, about 50% of eyepieces are under $100, but what it takes to make them glasses-compatible tends to push the prices higher.

Long eye relief means larger diameter lenses = higher cost.

 

A Barlow does lengthen the eye relief of an eyepiece, but not enough to make an eyepiece not compatible with glasses suddenly usable with glasses.

So a Barlow, though a nice accessory to have, isn't a solution to the problem of too little eye relief.

 

The Baader Hyperions will work fine with your f/10 scope.

As will these, that are less expensive and of similar or better image quality:

https://astromaniaop...lections/swa70°

For the 22mm and 32mm, you will need to have 2" capability.

[Jon Isaacs]

 

A Barlow does lengthen the eye relief of an eyepiece, but not enough to make an eyepiece not compatible with glasses suddenly usable with glasses.

 

So a Barlow, though a nice accessory to have, isn't a solution to the problem of too little eye relief.

 

 

What a Barlow can do is allow you to use a longer focal length eyepiece with adequate eye relief to achieve shorter effective focal lengths.

 

A 24 mm Plossl might have 18 mm of eye relief.  An 8 mm Plossl will have about 6 mm of eye relief.  But an 24 mm Plossl with a 3x Barlow will provide 18 mm of eye relief. 

 

Short focal length eyepieces with a decent amount of eye relief use this method...

 

Jon

[SeattleScott]

With expensive eyepieces, you are typically paying for long ER and/or wide AFOV. It isn’t that a Nagler has a dramatically sharper view than a Sirius Plossl. It is that it has a 60% wider view, and usable ER in short focal lengths (without glasses anyway). Delos/XW/SW, mostly you are paying for that long ER and wide AFOV. Sure there will be better coatings and baffling. Premium eyepieces have better glare control to do a better job on bright objects. The better polish should add a touch of contrast. But by and large, for general DSO viewing, the main difference is ER and AFOV. Especially at F10. Get below F5 and a Plossl starts suffering in terms of edge correction. But for most scopes, the contrast and abberations of a good quality Plossl will be maybe 90% as good as a premium eyepiece, at least for DSO viewing. So mainly you are paying for ER and AFOV.

[Kruegon]

My biggest obstacle is the lack of experience with various EPs. Everyone knows what a GSO plossl is like. Most have had a chance to view a Televue or Explore Scientific, at some point. But then we get into the Expanse, Luminos, Hyperion, Xcel, and so on. A lot of us beginner to mid astronomers have never had the chance to use these.

 

I just ran across some called Long Perng. Advertised 20mm ER. Mid priced. Well designed look. Might be exactly what I need. But are they any good? I haven't ever seen anyone with them and no one mentioned them. Leads me to believe they probably are not. And I have noticed that there are not many EP reviews on YT. I imagine this is highly related to the cost of investment to demo the products. I can't blame them there. Those Hyperions are starting to look a little tempting. The SVBONY Redline and Goldline look good via the specs, for the price. I have one GSO 2" Superview and absolutely love it, but they don't make 2" in shorter FLs.

 

I'm going to start asking within my astro society to see if anyone is willing to loan some EPs or share them at the monthly star parties. 

[Kruegon]

OK, you're on the steep part of the learning curve:

https://www.cloudyni...ce-aberrations/

 

Then, your choices:

https://www.cloudyni...ide/?p=12473522

 

Price-wise, about 50% of eyepieces are under $100, but what it takes to make them glasses-compatible tends to push the prices higher.

Long eye relief means larger diameter lenses = higher cost.

 

A Barlow does lengthen the eye relief of an eyepiece, but not enough to make an eyepiece not compatible with glasses suddenly usable with glasses.

So a Barlow, though a nice accessory to have, isn't a solution to the problem of too little eye relief.

 

The Baader Hyperions will work fine with your f/10 scope.

As will these, that are less expensive and of similar or better image quality:

https://astromaniaop...lections/swa70°

For the 22mm and 32mm, you will need to have 2" capability.

I have 3 scopes with 2" capability. Only the Mak is currently limited to 1.25". Oh and my 130ST is 1.25 only, but I may be parting with it now, since I have acquired the 8" f/4.9 OTA.

 

If I go with the Astromania, maybe I can pull off one or two a month over the summer. The Hyperions will definitely be one every month or two. Plus, I doubt I would need the 5mm or the 3.5mm options. Not technically within viable use for my scopes. Maybe on the 130 long tube newt.

Edited by Kruegon, 13 April 2024 - 11:54 AM.

[Starman1]

My biggest obstacle is the lack of experience with various EPs. Everyone knows what a GSO plossl is like. Most have had a chance to view a Televue or Explore Scientific, at some point. But then we get into the Expanse, Luminos, Hyperion, Xcel, and so on. A lot of us beginner to mid astronomers have never had the chance to use these.

 

I just ran across some called Long Perng. Advertised 20mm ER. Mid priced. Well designed look. Might be exactly what I need. But are they any good? I haven't ever seen anyone with them and no one mentioned them. Leads me to believe they probably are not. And I have noticed that there are not many EP reviews on YT. I imagine this is highly related to the cost of investment to demo the products. I can't blame them there. Those Hyperions are starting to look a little tempting. The SVBONY Redline and Goldline look good via the specs, for the price. I have one GSO 2" Superview and absolutely love it, but they don't make 2" in shorter FLs.

 

I'm going to start asking within my astro society to see if anyone is willing to loan some EPs or share them at the monthly star parties. 

Long Perng eyepieces have been around for many years under other labels.  Only recently have they showed up under their parent name.

The 80° LER eyepieces you see advertised are also sold as Orion LHD, Stellalyra UW, Founder Optics Marvel.  These only have long eye relief if you change the eyecups.

Their 55° eyepieces have been around a long time.  The first brand name was the William Optics Planetary, then Zhumell, then a host of other names.  These do have long eye relief all the way down to 3mm.

Their Plössls, with great reviews, have been around under other names including Smart Astronomy's Sterling line.

They are the maker of the majority of refractors out of Taiwan, and have been sold under many labels.

Long Perng eyepieces are high quality.

 

GSO Superview eyepieces work well above f/8 (just OK from f/6-f/8) but have a lot of lateral astigmatism in shorter f/ratios.

High Point Scientific sells them under the Apertura Super Wide name and they go down to 10mm.

Inside every eyepiece is an iris known as the field stop.  As the focal length shortens, the field stop shrinks.

By 20mm, the field stop fits inside a 1.25" barrel.  There is no reason to make any shorter focal lengths in a 2" size.

So you will not, in general, find any short focal length eyepieces in 2" unless the eyepiece is so big and heavy it needs a 2" barrel to support it.

Even the 13mm 100° eyepieces are 1.25".

[SeattleScott]

The Long Pern long ER ultrawides seem inconsistent. I have the 14 which is great, other than ER being tighter than advertised with stock eyecup. The 20 is also highly regarded. People don’t seem to be as crazy about the 1.25” ones. So while there are some winners there, especially if you replace the eyecup, I don’t tend to recommend them because half of them don’t seem to get good reviews.

[25585]

Any eyepiece can benefit from extra eye relief with a Barlow since it increases the eye relief. 

But that aspect decreases for shorter focal lengths.