Eye Pieces

[Stu1smartcookie]

Hello all ...Whilst i would not describe myself as a total beginner in Astronomy , but , when it comes to Eye Pieces ( we will call them EPs from now on) i have very little knowledge . 

Indeed , every time i see an EP come up for sale on here i wonder what it will give me as a replacement to my , admittedly poor selection . Let me tell you where i am on this ... I have about six 25mm and the same number of 10mm , basic EP's that came with various scopes a 6mm cheap plossl , ... 3 or 4 cheap barlow lens ... a rather nice little 26mm Celestron EP all of which are 1 1/4 " .. oh and one 2" EP at 28mm . i rather like the 2" EP and the Celestron 26mm ... to be honest the rest are at best barely ok . So with that in mind i think its time i invested in something decent . Sure , just like scopes there are a wide variety of prices and manufacturers that offer a great product . 

I want a nice widefield EP , maybe a mid range and probably something like a 5mm ... maybe a good barlow lens ... 

I was thinking along the lines of a zoom EP ie one size fits all ... Any advice on these would be welcome 

My ST80 can only take 1 1/4" EPs , so until i upgrade the focuser ( when i can actually find one ) i probably need to stick to the 1 1/4" ... I do however have another refractor that takes 2" EPs . 

Like most , i am never going to buy the most expensive ... but , i suppose ( if i can use this analogy ) its like buying tyres for the car ... you get the best you can afford . 

So ... come on guys , give me some personal favourites that you use ... and maybe tell me why they are so good . After all ,any knowledge passed on here will help a whole bunch of people that are starting out on their journey into visual astronomy 

 

Thanks for reading 

Stu

[Louis D]

If you're on a budget, I would recommend the BST Starguiders, especially at the 5mm to 12mm focal lengths.  They have good eye relief, good correction even in faster scopes, and a 60 degree apparent field of view.

For zooms, either the 7.2-21.5mm or 8-24mm varieties are fine.

[Nicola Fletcher]

I also use the BST Starguiders, they are great. I've recently bought a Baader Hyperion 8-24mm Zoom and I really like it too.

[wulfrun]

I have the SVbony 7-21 and a Hyperflex 7.2-21.5 zooms (long story why I have both). The Hyperflex does really well in my fast, small newt and possibly has the edge there. In the longer FL newt there's really not much to split them but the Hyperflex is 50% dearer. Both of them are lacking for FOV at the longer end so I dug deeper for an ES20/68-degree to cover that use. Zooms aren't for everyone's taste but I like the ability to dial-in on what magnification I want or need and I'm a very happy user. I know they aren't "premium" but I think they're excellent performance-for-money.

[Dark Vader]

+1 for Starguiders if you're on a budget. I have the 25,15 & 5mm. I got some good views of Mars last year through the 5 but it gives me 240x so at the top end of useful magnification most nights. The 25, while a step up from stock EPs is ok, but my favourite is the 15.

In terms of zooms - the Baader Hyperion IV with matching Barlow is very good. 

[Raph-in-the-sky]

And another +1 for BST starguiders (I have the 5mm and the 15mm)

Otherwise you could have a look at OVL Nirvana's (I have the 7mm and 16mm is on its way). Price is not crazy (69£ at FLO), you get a 82° AFOV and the general quality of the image is very good. On the other hand the range is quite limited, only 4mm, 7mm and 16mm. To me those EPs are among the best deals you can get in astronomy.

[Stu1smartcookie]

Well , already some very interesting replies , thank you for those . The BST starguiders certainly seem popular . I also really like the look of the Hyperion Zoom . There is so much choice . For me , this area is a minefield . What about Barlows ?.

 

[Raph-in-the-sky]

1 minute ago, Stu1smartcookie said:

Well , already some very interesting replies , thank you for those . The BST starguiders certainly seem popular . I also really like the look of the Hyperion Zoom . There is so much choice . For me , this area is a minefield . What about Barlows ?.

 

I also have a zoom EP and to be honest I barely use it. I much prefer fixed focal lengh EPs as most people do. A zoom EP is great for a travel scope as it allows you to have all required focal lengh (might need to add a Barlow) in a very small package. 

[Stu1smartcookie]

6 minutes ago, Raph-in-the-sky said:

I also have a zoom EP and to be honest I barely use it. I much prefer fixed focal lengh EPs as most people do. A zoom EP is great for a travel scope as it allows you to have all required focal lengh (might need to add a Barlow) in a very small package. 

Do you lose any clarity with a Zoom EP ?

[Raph-in-the-sky]

Just now, Stu1smartcookie said:

Do you lose any clarity with a Zoom EP ?

To me the main issue is the narrow field at high power. For example, my zoom which is a basic Celestron 8-24mm provides only 40° of AFOV at 8mm.

[John]

I have a 7.2 - 21.5mm zoom. One like this:

https://www.firstlightoptics.com/ovl-eyepieces/hyperflex-72mm-215mm-eyepiece.html

I often use it with a 2.25x barlow lens to get a high power zoom - 9.55mm - 3.2mm.

I also have a range of top quality fixed focal length eyepieces (Pentax and Tele Vue) and the zoom and zoom barlow combination compares surprisingly well to those in terms of optical quality. If I'm being very fussy or have a particularly challenging target I will use a fixed focal length eyepiece but very often the zoom does the job well.

The area that the zoom does not compete with is the field of view at the longer focal length end which is rather narrow but this is also the same with most other zooms.

I used to be a bit cynical about zoom eyepieces but over the past couple of years they have found a steady place in my eyepiece case and have proved very useful.

 

 

[John]

5 minutes ago, Raph-in-the-sky said:

To me the main issue is the narrow field at high power. For example, my zoom which is a basic Celestron 8-24mm provides only 40° of AFOV at 8mm.

It's usually the other way around with zooms - wider field at the short focal length and narrower at the longer focal lengths 

 

[wulfrun]

20 minutes ago, Stu1smartcookie said:

Do you lose any clarity with a Zoom EP ?

That would be hard to define, I suspect. Which zoom versus which fixed EP? On what target, under what circumstances? Or in a lab? Zooms involve compromises - but then again, so do fixed EPs. I think the question should be "will I notice in most circumstances?"

[Raph-in-the-sky]

20 minutes ago, John said:

It's usually the other way around with zooms - wider field at the short focal length and narrower at the longer focal lengths 

 

You re right! I got mixed up... I really don't use my zoom often!

I still find the AFOV too narrow ... now that I got used to 70-80° EPs, it's difficult to use something else.

Edited February 9, 2021 by Raph-in-the-sky

[Stu1smartcookie]

3 minutes ago, wulfrun said:

"will I notice in most circumstances?"

Sure , good point ... and also , how good are my eyes 

[Carbon Brush]

Not really mentioned...

Your preference on eye relief.
Some are happy with their eyeball almost stuck to the glass.
Other, particularly specs wearers, like to be further back.

When talking FOV. For planetary viewing you don't care.
But for larger (clusters) a wider FOV gives (I think) more of a wow, rather than a 'through the keyhole'.
A wider FOV also means there is less 'chasing' as a target moves across the sky, especially a consideration with a push dob.

Maybe an idea of your budget, whether individual or for a collection?

More coniderations and questions😁

David.

[Raph-in-the-sky]

5 minutes ago, Carbon Brush said:

When talking FOV. For planetary viewing you don't care.

Actually if you use a manual dob, a widefield EP on planetary allows you to stay longer on the target without having to nudge the scope... I find this valuable.

 

Edited February 9, 2021 by Raph-in-the-sky

[wulfrun]

I think the only way to decide if a zoom is for you or not is to buy one and try it. I like them, others do, others don't. It's a personal thing. Get a budget one like one of the SVbony range, if you don't like it you can sell it on and be down very little. Get a premium one and do the same, with a higher chance it'll sell on easily if you don't like it. None of them will compete with a wide-angle for FOV, whether that matters depends on your use. You already have longer FLs that you like though.

[Stu1smartcookie]

3 minutes ago, wulfrun said:

I think the only way to decide if a zoom is for you or not is to buy one and try it.

Yes its the obvious answer really , but its good to get other Views ( no pun intended) from users . I've just put a Hyperflex 7.2mm-21.5mm Eyepiece  into my basket on the FLO website .. looks like i will start there . 

[Louis D]

I mainly use my zooms in my binoviewer because it's a pain to swap two eyepieces instead of one and to make sure each is seated square to the holder so the images will merge properly.

In the central 50% of the view, most zooms perform about as well as Starguiders in my recollection.  It's at the edges that they start to lose out a bit on clarity.  That, and the field stop is sharp only around the middle of the range.  It grows slightly fuzzy toward both ends.  Not everyone is bothered by this, though.  In a binoviewer, you can't really look too far off axis without losing one or the other view, so that lack of absolute outer field clarity and field stop sharpness is in peripheral vision anyway.

[Raph-in-the-sky]

1 minute ago, Stu1smartcookie said:

Yes its the obvious answer really , but its good to get other Views ( no pun intended) from users . I've just put a Hyperflex 7.2mm-21.5mm Eyepiece  into my basket on the FLO website .. looks like i will start there . 

You can find these zoom second hand quite easily here or on UK astro buy sell. You could definitely save a few quids that way.

[Pitch Black Skies]

On 09/02/2021 at 14:07, Raph-in-the-sky said:

And another +1 for BST starguiders (I have the 5mm and the 15mm)

Otherwise you could have a look at OVL Nirvana's (I have the 7mm and 16mm is on its way). Price is not crazy (69£ at FLO), you get a 82° AFOV and the general quality of the image is very good. On the other hand the range is quite limited, only 4mm, 7mm and 16mm. To me those EPs are among the best deals you can get in astronomy.

Hi Raph, how would you compare your 2 BSTs towards your 2 Nirvana's?