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When is a premium eyepiece overkill? (On a cheaper scope)


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I hear a lot about the amazing contrast of the televue plossls and hutech orthos. I’ve thought about getting a TV 15mm Plossl and a 7mm ortho specifically for use in a C90 scope, but I’m wondering if it is overkill to buy a premium brand eyepiece for what is essentially a relatively inexpensive travel scope. Are the optics in the C90 a limiting factor, such that there isn’t much benefit buying a TV plossl over a generic plossl? Or is it generally the case that most scope have good enough optics that the quality of the EP is the main contributor to performance? (assuming that all other factors, such as seeing conditions, observer skill, etc. are equal). Probably not a question with a straightforward answer, but in general I’m trying to get a sense of when the quality of a scope begins to limit the value of an investment in more expensive eyepieces.

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Usually you want an eyepiece that matches the expectations of the scope. These days the Skywatchers scopes come with 2 eyepieces that will allow you to see things but really that is about it. May be a bit extreme but the supplied barlow and thw normal 10mm can be so poor they could put people off and I would generally suggest replacing them almost immediatly.

A TV plossls is good and I suppose the main advantage is they are not going to pull the scope performance down, cannot say much about Ortho's I don't have any. Until TV put the cost of the plossl's up they used to be the recommended upgrade here, when the price rose they ceased to be owing to cost.

The C90 is a SCT/Mak and that means that a means that you can use a less costly eyepiece, so a well made plossl should operate very well, instead of TV you could go for the Vixen plossl range. Here other brands have a good name such as the Revelation range however I would half expect to note a slight difference between them and the TV.

Will say that one aspect of the TV plossl's was that I never heard of a bad one and that "security" often made them attractive. You were not in a lottery of have I got a poor one, never heard of a poor TV plossl. Recently the Astro-Tech Paradigm has become a popular step up from the supplied items, in the US they are $60. They have good eye relief and are more parfocal.

A lot is down to cost, most do not want to put a $400 eyepiece on a $200 scope, but would consider a $60 eyepiece on a $200 scope. Unless you can borrow one then until you buy one and drop it in you will never be sure.

What eyepiece(s) have you at present?

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I would think that there has to be some sort of cutoff point to good EP/ cheap scope. Just as I know it works the other way around.

I would also think that getting a better EP would work out in the long run as if you plan to upgrade your scope at some point, the EP's are exchangeable. 

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The C90 has good optics so good eyepieces wouldn't be overkill at all. Premium eyepieces are overkill when the optics in them are better than the scope, for instance where plastic lenses are used or fast spherical mirrors are used (without a corrector) - the C90 has neither.

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I've always tried to use eyepieces that allow the scope and conditions to deliver the best image that can be obtained, ie: the eyepiece does not introduce any noticeable aberrations of it's own, noticeably reduce light transmission etc, etc. 

I agree that the C90 has good optics and would benefit from good quality eyepieces. 

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The thing with eyepieces is that they fit all scopes. So you can get a second scope or upgrade the current one and you dont have to change the eyepieces. This means they dont go to waste even if your current scope is teh suck. Usually also the price comes with larger AFOV and all scopes can benefit from that. 

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My experience has been that good eyepieces have always given an improvement in whatever scope I have used. There is much more that defines a 'premium' eyepiece than simply the optical quality. Build quality, fit & finish, ergonomics, and design aesthetics also play a part. My holiday scope is an ST80 that I use with Pentax XW eyepieces. £260 EP's in a £40 S/H scope. Crazy? ...the good glassware makes the little scope sing :)

I think of it in the same way as guitars and amps. The scope is the guitar and the EP is the amp. You can plug almost any old plank into a tube driven, hand-wired amp and it will sound sweet :)

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Rick makes a great point. I'd just add a note that your first eyepiece upgrade from supplied pieces to something in the £40-£50 range is usually the biggest leap in view improvement that you'll ever make. Up to £100 you'll get a further big step - but not so large as the first upgrade.

It's generally true that the more you spend on eyepieces after that - the smaller the differences will be. Further upgrades usually represent "smaller" refinements in view quality as your eye gradually gets trained to pick out  smaller inconsistencies in the fov. But you really can't beat a good quality eyepiece in even the cheapest scope - it changes everything. :)

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I have a used 114mm f4.4 newtonian which I got for £23. it's not the world's best scope but provides me with a cheap option for travel and for very wide fields (my other scopes are 6", 16" and 12" dobs). I intend to use one eyepiece with this scope, a 16mm Nagler and it provides great views. I see the eyepiece as at least half of the system and as you can always keep the eyepieces you have for future use then I'd recommend you buy whatever eyepieces you feel you can afford. I'd recomend televue plossls for sure as they are as good as anything else other than field of view and possibly eye relief.

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Reading through the various posts on eyepieces the impression that I get is that though the TV ones will always be good quality some of the cheaper ones will match them, but it will be a matter of luck as to whether you get ones of those.  The first eyepiece I bought was a 32mm TV plossl which is always the first eyepiece I use, but when I got a 15mm TV plossl it didn't seem to me to be any better than the 15mm on my Skywatcher 7 - 21mm zoom.  Indeed, if anything the latter was better.

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The eyepiece and telescope is a system, and its performance depends on the strength of the weakest link. That being said, the best view of Jupiter I have everhad came through a Skywatcher 6" f/8 dob with a Pentax eyepiece. I am sure it was the quality of the ep that gave it the amazing clarity of view that I had that night, It you can afford the ep it will work better than a cheap ep,and you can hold on ot it hwen you get a better scope.

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I would say that a premium eyepiece(s) may become overkill when you could use the money instead to buy a suitable larger aperture telescope.

In general I prefer the views with a £50 eyepiece in an 8 inch scope to the views with a £250 eyepiece in a 5 inch scope.

Of course that's just speaking in general, that some folks may get more performance by buying a bigger scope than with expensive eyepiece upgrades. I would not dream of selling my 100mm scope!

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RikM does make a good point, but his ST80 is by no means a stinker! Of cause he's going to use one of his "better" EPs in it, but if it were his only 'scope would he have spent £260 on an EP to go with it?

The C90 is by no means a stinker either!

So, I suppose there are several questions you need to ask yourself. Is this your "'scope for life" or might you upgrade at some point (As Luke has said, would you be better off saving the "expensive EP" dosh for a bigger 'scope?)? How deep are your pockets and so what is the budget you are considering (remembering, as people have already said, the law of diminishing returns!)?

Fortunately, the supplied EPs and barlow with my ETX90 were good, I thoroughly enoyed using them for over a decade! I went down the larger 'scope and then the new EPs route!  :grin:

But, at the end of the day, the decision is yours!

Cheers

Ps. Sorry to go on, but as a direct comparison, in my opinion in my 8" 'scope, the TV plossls were significantly better than the stock Skywatcher EPs, but only marginally better than Meade 4000 super plossls. If that helps!

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You don't need to pay a lot of money to get premium level performance eyepieces. Around £50 will buy a used Tele Vue plossl or a Baader Genuine Orthoscopic. These are excellently executed eyepieces and deliver optical performance as good as those costing £hundreds. What they don't do is to try and deliver a wide or ultra wide field of view as well or, in the short focal lengths, long eye relief. If you can handle those factors though, you can be using an eyepiece that could well be the strongest link in the optical system for a reasonable investment :smiley:

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RikM does make a good point, but his ST80 is by no means a stinker! Of cause he's going to use one of his "better" EPs in it, but if it were his only 'scope would he have spent £260 on an EP to go with it?

 Ha ha. You're completely right of course :) I bought the XW's to go with my Skyliner 250PX. That they work so well in a second hand guide scope was a very pleasant surprise :D

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I cant add much more to this, that has not already been said. I have bough/used Vixen NPL eyepieces that cost £30-40 each on a telescope that cost me £100 and again on a telescope that cost me £140.  Excessive cost...........considering?

Yes.

BUT you have to consider one thing:

The scope is only the vessel in which the eyepieces travel. If you have naff eyepieces in a wonderful scope....................the views wont be that good. If you have wonderful eyepieces in a naff scope................the views will be greatly improved.

Eyepieces can be used/transferred to other scopes. I now use those same NPL eyepieces in a scope that cost me 2K and the views are outstanding. I also use a Hyperion 8-24mm zoom eyepiece (cost a couple of hundred squid), in the scopes that cost 100-130 squid and the views are great.

The cheapest part of astronomy is usually the scope. Its the rest of the stuff you buy after that costs the most.

I bought a 6mm Celestron Omni eyepiece for 60 quid to use with a 130 quid scope. I used it once with that scope. Now it gets used a lot more with the 2K scope.

I'm now done buying scopes and i really dont think i need to buy any more eyepieces either.

I'll never say never though.   

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I'll bet my ST80's better than your ST80 Rick - cos I put Ethos's in it lol :grin: :grin:

FOV is overrated, you may just get lost in it like swimming in an ocean instead of focussing what you should be looking at :0)  

Let the Pentax <  ethos debate in the ST80 begin  :D

Puts on coat quickly and runs out of the room ... 

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it's actually cheaper to buy a smaller/shorter scope than a mega wide field of any sort of quality to widen the field available to you.

Quite right. Harder to explain to ones other half though !  :wink:

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Lots of insight and thoughtful advice in this dialogue! The other EPs I have that I use with the C90 are the kit 32mm Celestron Plossl, a 25mm Celestron Plossl that came with another kit (seems to be an E-lux), and a 24-8mm celestron  zoom that I picked up for the convenience that it provides. The 25mm Plossl seems to be the best of them, but it isn’t exactly a Tele Vue and I have no premium piece to compare it with, so I have no idea if I am missing out on something, or if I would even be able to tell the difference.

The zoom is convenient, and technically it eliminates the needs to get a 15mm Plossl and 10mm Ortho, but I am one of those stubborn old fools who clings to the archaic notion that zooms always involve some kind of compromise in optical quality. I might keep the zoom when I use the scope for terrestrial viewing, but for the night sky, I have this nagging feeling that I could get more from a 15mm TV Plossl and 10mm Ortho. It’s an F14 scope, so I’m guessing the zoom will appear as well corrected as the plossls, but it’s the vaunted Tele Vue contrast I’m looking for…  Seems like most people suggest that I will indeed be able experience the benefit even in a C90 with a stock diagonal.

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Great thread.

Surely if you jump straight from the stock eyepieces into the gourmet TV territory, you won't understand / appreciate what a great view you are getting. Surely there is pleasure to be had from working up to it. Could be that you feel that you don't need to go the whole hog across your whole collection?

How about the second hand market? These things don't wear out. Maybe buy one second hand and replace with new if you feel the need then dispose of surplus through the classifieds?

You will probably notice that there is a lack of green in my limited collection so it is entirely possible that I am talking absolute rubbish - in which case please accept my apologies.

Paul

NB. Managed to temporarily stave off the cravings by ordering the 28mm MV. It is only a matter of time.......

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I steadily worked my way up. It has cost more in the long run but have appreciated each incremental improvement along the way.

SkyWatcher MA --> Revelation Plossls --> Baader Hyperions, Meade 4000 SWA and Vixen LV --> Pentax, Explore Scientific and Televue.

Same with telescope aperture although I have now started to increase field of view.

60mm Refractor --> 6" Newt --> 10" Newt --> 80mm refractor --> 70mm refractor

I feel sure if I had jumped in at the top end straight away, I wouldn't have appreciated the different qualities of the instruments nor learned how to get the best out of the equipment and my observing techniques along the way.

Just my opinion though, other opinions are available ;)

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