Step up eyepieces

[Placesinthedark]

Hi all,



Recently I got a 10" dob and I've been loving the views and enjoying the experience. As with all hobbies you learn more and more the more you put in.



What I've found is I'd like to know what other eyepieces are like. I have a



25mm Kellner (cheapo thing but actually my favourite)
10mm super plossol came with scope and feels restricted to look through
30mm starguider 2" (not bad but the edges of the image are weird and warped)
15mm plossol (again the view is hard to get and feels restricted)



I'd like a planet eyepiece like 5-9mm that doesn't feel like I'm looking through a pinhole, if that's possible?? :shrug:


And a 20-25mm with a nice bright sharp view, the kellner is easy and bring to look through.


Any eyepieces you think could fit the bill at $200 or so each?



Thanks for your time with this :)

[DeWynter]

For the planet one try to get Vixen SLV. They are about $200 AUD delivered. myastroshop.com.au has wide range of them. Sorry, no 2.5mm - I got the last one. :) They have 50° view, but for planetary viewing it's perfectly fine. Image quality is quite high.

For the 20-25mm range try Explore Scientific 68° series. They (20mm and 24mm) are relatively cheap and and would cost you about $200 AUD delivered from US. Not sure who is selling them here in Australia. ES 68° 24mm is arguably the best in the 68° series with great image.

If you are willing to pay more then try Explore Scientific 82° Series 30mm - an outstanding eyepiece for very moderate price. Solid piece of glass and metal. Weight 1kg(!!!) About $300 USD. I guess only TV Nagler 31mm or Ethos/Delos can beat it, but at a completely different price. :)

[Wavytone]

Although being in Stanhope suggests you’re a bit isolated I’d suggest attending some star parties and trying other people’s first before buying anything.

Otherwise you risk buying and selling several before you settle on some you like.

Sorry Ilya but wide angle eyepieces don’t need to be big, heavy doorstops, nor the size and shape of Coca-Cola bottles.

[mental4astro]

There's one thing that is critical to understand about telescopes and eyepieces in oder to make the best choice for YOUR scope - optical matching.

This starts by understanding that all telescopes produce a CURVED focal plane, not a flat one. We are made to think that a telescope focuses to point. This is true only for a single star. But there are stars all across the field of view. When all the stars are plotted at focus across the focus of a scope, you will find that they are spread across a bowl shaped plane. The bowl can be either convex (for refractors, SCT's and Maks) or concave (Newts).

The second part is that it is easier to design EPs for a convex focal plane, and cheaper to manufacture. The concave focal plane of Newts is much more difficult and expensive to design and manufacture EPs.

This is why Naglers, Ethos and the high end Explore Scientific EPs are significantly more expensive than other EPs - these are desinged for Newts.

Match the EP to the scope and you will end up with an image with minimal or no aberrations.

It is when you put an EP designed for the opposite shaped focal that things CAN go pear shaped very quickly with a wide array of aberrations visible, such as astigmatism, field curvature, chromatic aberration, etc.

[mental4astro]

As Newtonians present such technical difficulties, and Newt specific EPs are so expensive, finding inexpensive and optically good EPs can be difficult - but it's not impossible!

There's a trick to this. And it comes from the complex nature of contemporary EP designs meaning that there are some convex specific eyepieces that actually do a fantastic job in Newts as well. From a given line of eyepieces, take for example the Baader Hyperion line, every single focal length shows significant aberrations such as astigmatism and field curvature EXCEPT for the 5mm! The 5mm Hyperion is sensational in Newts as fast as f/4.

There may be just one, or two or three individual EPs from a whole line that perform really well in Newts, so it is important when reading reviews to make a point of finding out what scope an EP is being used in so you can figure out if the EP being reviewed is good for your Newt or not. As most people do not know about optical matching, they may write off an entire line wholly because they used the EP in the wrong scope design. This is VERY COMMON. The amateur astronomer in the know can "read between the lines" of these reviews.

For some of these less expensive gems, you may need to cope with some mild aberrations, but these will be right the very edge of the field of view, where no one does any serious observing. Accept this, and some absolute and less expensive gems can be had! :)

[DeWynter]

That's true if we are talking about f/9 and slower refractors or short focal length eyepieces. But as soon as we need something like 28mm-30mm and longer with wide field for Newtonians - we are talking about big, heavy and expensive things. Unfortunately...

[mental4astro]

There is one more thing to understand about Newts, and it has to do with coma correctors. Newts come in a variety of f/ratios, just like every other scope design. What this means is not just a photographic ratio, but describes how deep the focal plane shape is. The faster the f/ratio, the deeper the focal plane. How deep the focal plane is will also dictate how well the EP is matched to its specific shape, convex or concave. So even with EPs designed for a convex focal plane, a particular line will perform better in slower refractors than in faster ones.

What this means for Newts is that Newt specific EPs will show more or less coma depending on the f/ratio, and off course it will be more with faster f/ratios.

How significant coma is as a distracting aberration depends entirely on the individual person. I'll give you my own experience and situation. I have Newts from f/4 to f/5. I only ever use a coma corrector in my f/4 Newt and only with my 30mm 82° eyepiece. Same EP in every other Newt of mine, the eyepiece cleans up the coma really well and I find no need for a coma corrector. A coma corrector is not mandatory in Newts.

What a coma corrector won't do is clean up astigmatism or field curvature. These are different aberrations.

[mental4astro]

Stephen,

The weird shape that you are seening at the edge of the field of view of our 30mm is astigmatism. It is the prime symptom of an optical mismatch between scope and eyepiece. The hardest gem EP to find for Newts is long focal length ultra wide angle. I have not found a cheap 30mm EP that doesn't show a lot of astigmatism. Unless you shell out the big bucks for an Explore Scientific or TV, you will need to tolerate a lot of astigmatism.

A little shorter focal length that is bloody good in Newts, especially at f/5, is the Celestron 23mm Axiom LX. Available now only 2nd hand, but inexpensive (less than $150). The Luminos 23mm is not the same design and does not perform anywhere as well in Newts.

A decent and inexpensive 15mm is the GSO Superview. It will show a little astigmatism, but it is not grotesque at f/5. It is also a really easy EP to use as you don't need to struggle to look into it. People tend to hold onto their Superview eyepieces as they perform really well for their price. Best in slower refractors & in SCTs and Maks, but respectable in Newts if you are on a tight budget.

In short focal length EPs, the Explore Scientific 82° line isn't outrageously expensive, usually less than $200 even new.

If your budget is tight, the TMB Planetary Type 2 line is a bargain! They all have a BIG eye lens (the lens you look into) and all have the same generous eye relief meaning you won't need to park your cornea onto the eye lens to look into them, not even the 2.5mm. They will all do a good job in Newts, but the very best performers are the 7.5mm 7mm, 5mm, .5mm, 4mm and the 2.5mm. These were specifically designed for refractors, but in Newts they do very well. You will find these on Ebay for less than $50 each. Do an Ebay search for "SWA eyepiece".

Other people will be able to recommend other gems for your Newt. But all the same read as much as you can, and learn to identify the clues that indicate optical matching or not. It may be just the one single focal length from an entire line, but that's the gem! ;)

Alex.

[silv]

Awe, Alexander, you did it again. I understood a lot from your again-great posts. If I may ask a question in your thread, Stephen?

Can we tell from the build type https://en.wikipedia.org/wiki/Eyepiece#Eyepiece_designs which EP is designed for correcting concave (Newts) and which convex (refr., CS, Mak)?
For example, if a lens design ends with a concave one nearest the eye-end, it'll correct best in a newt? Or vice versa, a lens design ending with a convex will best correct in a newt?

Will a barlow mitigate or amplify the eyepiece design mismatch in a newton?

[mental4astro]

Great questions, Annette! :D

I'll start with the barlow. Most people think that a barlow is somehow a neutral or non-active optical element. Thing is there is no optical element that is neutral. ALL are active. This includes the human eye which has its own aberrations unique to every individual, and its own set of corrective capacity. Barlows can both exacerbate and mitigate aberrations, depending on the EP/scope combination.

As for which determining which EP design is best suited to which scope, there's two parts to this. One is knowing that most EPs are designed for a convex focal plane. But remember, this is not a hard and fast rule as EP designs are not geometric in their aberrations. Take the Plossl and Orthoscopic designs. Both are old designs (more than 100 years old). Their lens design/arrangement is the same in all focal lengths, including the glass type. What changes to give the different focal lengths is the thickness of the lens elements and the radii of the various surfaces. And this in turn means that there will be differences in performance between the different focal lengths across all the different scope types AND between focal ratios. Hang on there, I'm coming to a point... The above is to say things are not so straight forward...

Now, the plossl design was made for Newts. But when it was created, Newts were f/7 or slower. You will find that plossl performance is challenged as the f/ratio gets faster.

As for which other designs best suits Newts, this brings me to the second part of the reply. EP manufacturers will never say this. The reason being is as most people think a scope is a scope is a scope, they also think and eyepiece is an eyepiece is an eyepiece. So if a manufacturer were to say that their $200 eyepiece is best for refractors, people will think that there must be something wrong with that line and will not buy it. This leaves us amateurs kicking the can, spending our hard earned money, getting ****ty results with these eyepieces, and dismissing outright entire lines solely because of our ignorance. But all is not lost. It is with threads like this that the how and why of EPs and optics that shed light on the true relationship between EPs and scopes, and everyone learns how to recognize the tell-tale aberrations of optical mismatching. Astigmatism being the key one.

Remember, even between high end EPs, performance will vary between individual EPs, and will again vary between different scope designs and focal ratios, this includes with Newt specific eyepieces. A 20" f/4 Newt will have a focal plane of a different radius from an 8" f/4 Newt, and so EPs will perform a little different again. ALSO, an EP line today is defined by all the EPs first having the same Apparent Field of view, and the same or similar amount of eye relief. The ONLY difference being focal length. So the internal design and composition of the different glass elements, and number of elements can differ tremendously. It is nothing like old EP designs, like the plossl, which was a four element design in two groups. Look closely at the spin on EP adverts today and you will read stuff like "EP design with 5 to 7 elements"... This is not a "plossl" design now, is it. Things are never straight forward.

239112

Oh, and so you know, to recognize astigmatism, the stars along the edge of the field of view appear as little "seagulls", cocentric to the centre of the field of view. The more grotesque or larger the seagull effect, the more the optical mismatch. Coma makes stars appear as little comets radiating out from the centre. If all you see is coma, THIS IS GOOD! Seagulls not so good, but not necessarily fatal either. It also depends on your individual eyes and your preferences as to how much it bothers you. Recognize astigmatism being described in a review, and you will be streets ahead if the author of the review doesn't! :D

There is one more line you may like to keep an eye out for your Newts, the Vixen LVW line. Though now discontinued, they are now pretty much just second hand items. One brilliant thing about this line is they are one of the very few lines that perform really, really well across all scope designs! Yes there will be some slight variations, but as a whole they are very bloody good.

Oh, many people also think that the Baader Hyperions are a copy or clone of the LVW's. They are not. They are only similar in size and colour coding, but the Hyperions are designed for a convex focal plane. Their internal design is not any form of copy of the LVW.

I hope this answers some of your questions.

[Ukastronomer]

I use Vixen LVW (W is Wide) eyepieces, they are not cheap and very occasionally available pre owned

I mainly use 2" but for 1.25, Vixen, they are quality

This is the new range

https://www.vixenoptics.co.uk/Pages/ssw_eyepieces.htm

[Wavytone]

No, you cannot.

FIRST, four general observations:

A. The problem depends on focal ratio - squared. In scopes with fast f-ratios (f/7 and under) matching the eyepiece to the scope is a significant issue, and at f/4 it is a huge problem. OTOH at f/10 (Celestron/Meade SCTs)it is not an issue and almost any eyepiece made in the past 100 years will work fine.

B. In the US the telescope market is dominated by large fast dobsonians and Celestron SCTs. The two main US eyepiece brands - Televue and Explore Scientific - both have tailored their eyepiece designs specifically to suit fast newtonians, not refractors. What that means will be evident below.

C. In Europe and Japan the telescope market is dominated by small refractors, which have field curvature opposite to that of newtonians, and no coma.

So it should be no surprise that the premium Japanese eyepiece manufacturers - Vixen, Pentax, Takahashi, Nikon, and Masuyama - all make eyepieces optimised for refractors, not Newtonians.

D. The cheap Chinese "budget" eyepieces such as GSO, Prostar and numerous clones... aren't optimised for anything and you're taking pot luck there. But one thing is for sure - they'll all work reasonably well in SCT's.


DETAILS: The real problems are:

1. The aberrations of a complete system (ie telescope + eyepiece+ eyeball) are the sum of the aberrations contributed by each element, ie telescope and eyepiece and eyeball.

A good choice of eyepiece can negate the aberrations of the scope (and the result is very good). For example, Newtonian scope (coma and positive field curvature) plus Plossl eyepiece (negative field curvature) = very good.

A poor choice of eyepiece makes matters worse. For example, Newtonian scope (coma and positive field curvature) plus Erfle eyepiece (positive field curvature) = quite poor.

2. Field curvature of the eyepiece is a parameter that manufacturers do not disclose - in order to keep people guessing and shelling out $$$ to find out the hard way.

3. Coma, or the lack of it, from the scope and whether the eyepiece cancels that. From trying eyepieces in the field with various scopes over 40 years it is quite evident all the Televue eyepieces MUST have some negative coma to cancel the coma produced by fast Newtonians, but those from the Japanese makers do not.

Alternatively if you really want to use an f/3 Newtonian visually, you had better add a coma corrector (eg. Televue Parracor, there are others).

3. Astigmatism, in the observers eye. Televue make a gadget to correct for this - the Dioptrix.

FWIW I use Vixen SLV and SSW eyepieces with my scope, which is a 9" f/13 Rumak. It has a fully corrected flat field - no need to pay the Televue Tax - and doesn't do low power... it starts at 100X and runs to 660X.

[mental4astro]

What Wavy and I are saying, to just give a dumb "get this and that eyepiece" is to do you a disservice. It can also create a brand prejudice (in favour or against) based on ignorance or on Brand loyalty, not on optics or understanding or $$$ situation.

Understand HOW EPs and scopes work together, and you will be able to make better choices for YOUR scope and situation. This way you will be able to knowingly work through the flash spin of advertising, the ignorance displayed in many reviews (most unfortunate), and not be seduced by the cheap prices of some eyepieces that in reality will not give you what you want.

Even with expensive eyepieces, there's those that are better suited to different scopes. BIG BUCKS does not guarantee an optical match, nor a performance you seek. Don't forget your eyes are also an active element of the optical train...

There are also those inexpensive gems. But there is a lot of stuff to sort through in order to find them. And an understanding of how scopes and EPs work will not only make it easier to identify them, but may actually give you just what you want without killing the piggy bank. :)

If you can, do look through as many EPs AND scopes as you can so you can make sense of all Wavy and I have rabbited about. Star Parties are great for this. If getting to a Star Party isn't practical, read carefully and read a lot before laying your money down.

My own kit is a collection of EPs I've cherry picked that have performed brilliantly to my eyes. I have a variety of scopes, Newts, SCTs, Maks and refractors, and they all have different optical characteristics, so I have EPs that are excellent for those scopes, many EPs are scope specific, very few are excellent in all scopes, some are expensive and others are inexpensive gems :)

Alex.

[Placesinthedark]

Thanks so much, will look into ES eyepieces

[Placesinthedark]

Yes, there is a Toowoomba astronomy club but they don't seem active by their webpage :(



In that case I would love to try out different eyepieces for sure, but the plossols just seem so constricting for me and I'd love to see more Wide angle stuff.

[Placesinthedark]

Thanks so much for this info! I had no idea I needed to match the scope with the eyepiece. Phew, glad I asked otherwise I might have spent some serious money.



So I might have to bank a bit more cash before I go looking for my next eyepiece...

[Placesinthedark]

I've seen the Hyperion at Astro Anarchy for a decent price...I might start with that, but worried a 5mm would only be useful with perfect conditions and optimal cool down.

[Placesinthedark]

Alright, after reading all the excellent and in-depth replies I think I need to just try and go to a star party and try out a bunch. I'm thinking there are a few elements to design and personal preferences which need to be considered - yes, price as well, but seems it's not as a easy and length = perfect choice.



At least it gives me time to save some money and the eyepieces I have aren't hurting me or anything.


Now...to get a drummers chair or some such so I can sit comfortable which star gazing.

[astro744]

Yes definitely go to a star party and have a look through different eyepiece telescope combinations and preferably in your own 'scope. Try different focal lengths too.

Other than that give Bintel a call as they currently have Celestron X-Cel LX on sale and these would definitely be a step up from your stock Plossls although I have not personally used these so I recommend advice from Bintel.

See https://www.bintel.com.au/product/celestron-x-cel-lx-eyepieces/?v=6cc98ba2045f

and https://www.cloudynights.com/topic/474474-why-no-reviews-on-celestron-x-cel-lx-eyepieces/

If budget was not an issue I would recommend Tele Vue as these are highly corrected eyepieces and work well in ANY telescope to f4. Primary mirror coma can also be corrected with the Paracorr. Note primary mirror coma alone is quite insignificant compared to the aberrations caused by a poorly designed eyepiece and a Paracorr won't make a poorly designed eyepiece perform much better other than adding a 1.15x amplification giving a flatter field.

See http://www.televue.com/engine/TV3b_page.asp?ID=2

Tele Vue also make Plossl types and although these are high quality the design still means a small eye lens and short eye relief especcially in the 8 & 11mm.

If you can find a used Nagler, any TYPE (generation) within budget, go for it. Any of the newer types (DeLite, Delos, Ethos) will serve you well too with the first two having the long eye relief. A used Tele Vue Radian would also be excellent value.

Whatever you choose, enjoy!

[Wavytone]

Stephen,

Many beginners are struck with the "stick your head in a fishbowl" effect of the UWA eyepieces (Ethos etc) - I agree it is amusing at first and useful on large extended nebulae and a handful of the larger galaxies, but ultimately I regard it as a party-trick.

In some situations UWA eyepieces aren't ideal for getting the most out of your scope on small objects because flooding you eye with things to look at affects your eye's dark adaptation ( ie night vision).

Conversely the smaller field eyepieces (such as Plossls, Orthoscopic, Vixen LV, Edmund RKE) have a much smaller field stop, which simply blacks out a large chunk of the field in your eye. The dark adaptation of your eye responds accordingly and is improved when looking at faint smallish objects like planetary nebulae and small galaxies, as well as the planets at high power. The effect is easily demonstrated in light-polluted urban skies, and even in Bortle 2-3 skies (Blue Mountains) it is noticeable.

A similar technique some use is to cover the observing eye with a black eyepatch while not actively observing, and only uncover it at the eyepiece. This assumes you have two good eyes (I don't) so you won't stumble around tripping over stuff in the dark.

The second aspect to consider is maximising contrast vs scattered light and ghosts in an eyepiece; these are a function of the number of air-glass interfaces in the eyepiece (fewer is better). For this reason some have monocentric or even spherical ball eyepieces (2 air-glass surfaces) which offer the ultimate contrast at the expense of a small field of view.

Many years ago an experiment was conducted in which a group of experienced observers, scopes and eyepieces were tested to find out what magnification/eyepieces were optimal for faint objects - specifically galaxies, as the application was visual searches for supernovae. It concluded that for faint objects there was indeed an optimal magnification - that which gives an exit pupil of 1mm, or X1 per mm aperture of your scope. This is surprisingly high magnification - not low power at all.

[DeWynter]

Stephen,

please remember that despite the fact that all what Alexander and Nick have said about choosing eyepieces is correct, you are still in the beginning of the journey and at that stage it could be difficult to digest and apply all that knowledge and therefore sometimes simple and dumb suggestion to "get this and that eyepiece" is exactly what you need. I still very grateful to people at CN forum for suggesting on buying Baader zoom eyepiece at the very beginning and before I read all these articles about how zooms are bad. :) If I read all that I would never buy it and therefore I would spend lots of money right at the very beginning trying to find ideal eyepiece instead of just observing. Same here - you can start digesting all reviews, trying to understand all issues big boys are dealing with instead of just observing.

Let me provide an example from non-astronomy fields. Can you do 4WD driving on a stock Nissan X-Trail or Toyota RAV4 SUV? Of course you can. I did that for many years with no issues, knowing the capabilities and limitations of the car. However if you read 4WD forums then the suggestion would be "No, you cannot. Get a proper lifted 4WD." And then there could be explanation why. And it will be a proper and correct explanation, but you do not have that. You've got only a SUV and what to start. And the explanation is based on big boys needs. Not yours. So instead of saying "no, you cannot" there could be a suggestion - yes, you can do Stockton Beach sand driving or Lost City, but do not go to Monkey Gap. Or photography – can you make beautiful pictures with simple point and shot camera? Of course you can. If you read photo forums then the suggestion would be to buy a full frame camera and pro lenses with proper explanation why you need that. Yes, you do need that when you are doing that professionally, but not at the very beginning. I'm a pro photographer for quite a while (I've got business, profit etc.) but at the same time I understand the difficulties for the beginner. These are proper suggestions, but even reading all these articles will not save you from lots of frustration. Unfortunately it is a trial and error journey in any case. But you need to start with something.

So my dumb suggestion was based on a few facts:


The suggested eyepieces are within the focal range you need.
The suggested eyepieces are within the price you need.
They both have long eye relief (18-20mm) in case you are wearing glasses.
They are of light to moderate size and weight. Not like "hand grenade".
ES68 24mm has generous field of view which means you won't be looking through a keyhole.
They both have great image quality and perform quite well in fast Dob/Newts, not even counting slow scopes.


Hopefully that will delay some frustration on your eyepiece selection journey for some time and just gives you time to be prepared for the next round. :)

[mental4astro]

"Looks" like so many eyepiece options...

One thing that you may think is the case with eyepieces is there is a wonderful array of choices. That's what we are led to believe. Reality is a very different situation.

Most telescope manufacturers appear to also make and sell their own eyepieces. No one makes their own eyepieces. Celestron, Meade, Skywatcher, Saxon, TV, Baader, etc. All their eyepieces are made by a handful of predominantly Chinese manufacturers.

And the true variety of eyepieces is actually very limited. Most telescope companies will commission a manufacturer to make a run of eyepieces for them using this or that optical design, with the only differences being external cosmetic ones, and occasionally variations in coatings. Because so many people are ignorant of how all of this works, they will say this eyepiece is a "copy" or worse still a "clone" of that eyepiece. They are the same bloody eyepiece...

Take the Baader Hyperion line. These are the exact same as the Saxon SWA, the Celestron DUO, the Orion Stratus, and a few others. Their differences are all only skin deep as optically they are all the same. Same goes for the majority of other eyepieces, plossls, kellners, wide angle, etc. It is extremely expensive to design unique EP optical designs. It is much cheaper to use an existing optical design and just change its colours. That's business.

Now there are some exceptions. Some manufacturers will make a line exclusively for some scope companies. TV's are made in China, but their designs are exclusive to them. Vixen with its high end designs the same. This also goes a long way to explaining the premium one pay for such eyepieces. There's not many firms that will do this.

Don't feel cheated though. It's actually a good opportunity though if you know your way around to pick up some real bargains!

Take the Vixen LVW line (again, the Baader Hyperion line is NOT a copy or clone of these). These were rebadged as the Orion Lanthanum Super Wides. This Orion line ran for just a couple of years and then discontinued. Same great optics, but much cheaper! Even second hand the Vixens command a better price. But if optical performance is more important to you, you now know where the bargain lies.

So now all of a sudden, the world of eyepieces had just shrunk!

Rather incestuous, but that's business. Every industry does the same, not just scopes.

Brand prejudice...

This is another gem provider! :D There are some firms that have a cult following, yet others may as well be lepers. Celestron is one of latter. They occasionally offer some outstanding EP lines, but because they carry the wrong name and colour, next to no one gives these eyepieces a chance. The discontinued Axiom LX line is one such example. Designed for a convex focal plane, these are really great performers, and some individual focal lengths also do really very well in Newts too. The Luminos line is NOT the same optical designs, despite the same focal lengths, and they do not perform the same way. Read a lot, and you will be able to find some real gems and bargains.

Alex.

[DeWynter]

Off-topic:

Alex, you do need to combine all your posts into proper articles on this forum. Things like 'Understanding Nebulae' and 'Observing the Moon & Planets' deserve to be as articles with proper formatting.

On-topic:

I wish all these great second-hand EP were available on the market. On CN classified you can find gems from time to time, but quite often they are not sending overseas. Or even not accepting PayPal - money order or cheque only!!! :rolleyes: Hey, it's 21st century now! So it will take quite a bit of time to find what you need here in Australia. Or might not find here at all.

[SkyWatch]

Hi Stephen,
Another option for planetary/high power viewing is the Orion Edge-on series (see, eg: https://www.bintel.com.au/product/orion-edge-on-planetary-eyepieces-1-25-inch/?v=6cc98ba2045f ). These are identical to the Long Perng ones (which are lots cheaper!), but they seem to be sold out at Andrews (although it might be worth giving them a ring: see http://www.andrewscom.com.au/site-section-10.htm ). Williams also brand them, but at a higher price than Orion and Long Perng.
They have a 20mm eye-relief, which makes them a lot easier to look through that the supplied plossls, and I find them nice and sharp with a good FOV.
I have tried the 9mm, 6mm, and 3mm Long Perng versions in my f5 Newtonian as well as f6 and f8 refractors: and they are all fine in all the scopes.
If you do go down this road though, I think you will find that the 3mm wont get as much use as the 6mm, simply because the seeing wont allow you to go to that power anywhere near as often.
Good luck with your search!

- Dean

[Ukastronomer]

In the UK we have the Distance selling regulations (act) which allows us by law to return anything bought FREE postage within a few weeks for a refund, allowing things to be tried out, such as eyepieces, do you.

Also if like me you are loyal to a reputable seller, with me it is the Widescreen centre who have been around for 30 years, I can ask Simon to try before I buy, do you have shops like this

https://www.widescreen-centre.co.uk

[Wavytone]

Ditch the compass.
Ditch the phone except as an atlas, which it’s good at
Forget about altitude, it’s irrelevant.

Use the method in the other thread I linked. Print it off if need be so you can read it in the dark.

Technology is a crutch which is dumbing most of you down. We didn’t have or need it, 30 years ago. Let go of it, look up and learn the basic visual skills.

[Placesinthedark]

Thanks all, will be referring to this thread and saving some money for the future. Probably try and get into a star party, if any close by, and just try before I buy. Might pop into Astro Anarchy and have a chat next time I hit Brisvegas. :thanx: