Eye pieces

[Ewee]

Hi there, I have a question regarding eye pieces.. I'm ann absolute noob.i have an slt 130,, worth a 10mm and a 3x Barlow lens only. I'm not sure what other lenses to get. I think I'll mostly be looking at  planets but would like to view dso if possible at some point. Can anyone suggest what eyepieces to purchase? My budget is not wonderful so is there a not so expensive a brand worth considering that five reasonably results? Kind regards, Neil. 

[Zermelo]

For a first value-for-money upgrade, try these:

https://www.firstlightoptics.com/bst-starguider-eyepieces.html

and have a look here:

 

[cajen2]

Z is quite right: the BST Starguiders are one of the best VFM eyepieces around. In your position, I'd get a 25mm for wide views and for finding objects, plus an 8mm for good magnifications on the moon and planets. When you feel rich enough, you can start 'filling the gaps'. A cheap alternative to the 25mm BST is a Vixen NPL. I have the 30mm and it's excellent for the price (but don't get the lower focal length ones as they can have a problem with eye relief).

[Franklin]

I'll second the BST range, excellent for the money. The 25mm, 12mm, 8mm and 5mm were my eyepiece set for years, can't fault them at the price and they come up quite often in the classifieds for around £35, bargain!

[LukeSkywatcher]

I always recommend Vixen NPL eyepieces. They are obviously of superb quality, but are very affordable (about £30 each).

I think a good eyepiece collection really should have an 8mm,15mm and a 30 or 32mm.

I suppose it depends on the scope, but I find these 3 eyepieces work well across all my scopes. 

Edited August 25, 2022 by LukeSkywatcher

[Franklin]

23 minutes ago, LukeSkywatcher said:

I always recommend Vixen NPL eyepieces.

Vixen NPL's are very good value as well but I wouldn't recommend going lower than the 8mm possibly even the 10mm due to tight eye relief. The 30mm is a fantastic eyepiece for the money, everyone should own one.

[LukeSkywatcher]

1 minute ago, Franklin said:

Vixen NPL's are very good value as well but I wouldn't recommend going lower than the 8mm possibly even the 10mm due to tight eye relief. The 30mm is a fantastic eyepiece for the money, everyone should own one.

8mm is the lowest I go. Great for planets. My 30mm is my workhorse for scanning the sky. 15mm is lovely for a bit of a wider view of planets such as Jupiter and its moons. 

[Zermelo]

I agree with the comments above about the Vixen NPLs for longer focal lengths. I have the 30mm, which works very well for me in an F/5 scope. The 25mm is possibly superior to the equivalent Starguider (and I see that FLO have now started to stock this focal length - except that it's currently out of stock!). Any shorter than that, I'd go with the Starguiders.

 

[DaveL59]

I have the 30, 20 and 10mm NPL and find them all good and easy to use, fine also in the x2 barlows. My scopes are all long FL in the F10 region so can't comment on faster ones.

[Ratlet]

Bit late to the party, but I'm also a complete noob and have the 130pds (same aperture and focal length as the 130slt). 

I picked up the 8mm BST and it gives very nice views of the planets. It's a great focal length for views and you can pick up a good bit of detail.  It's also a decent FL for DSO's.  Got a real nice view of M13 and I could swear I saw some granularity, although that might have been wishful thinking.

But you should also pick yourself up a +/-30mm Plossl.  I got an SVBONY SV131 (32mm, 48° FOV) for £23 from AliExpress (I was ordering other bits and pieces).  I honestly get more use out of the Plossl.  The vixen would be a good shout unless you were desperate to save the cost difference. 

[leo82]

I started off with the standard 25mm and 10mm that came with my telescope. The 25mm ain't too bad but the 10mm isn't the best. The first thing I bought was a 2x Barlow. This meant I now had a 25mm, 12.5mm, 10mm and 5mm. As the 10mm isn't the best I bought an 8mm BST.  This was such a difference compared to the standard 10mm. I'm looking to replace the 25mm now for a wider field of view. 

To answer your question, the first eyepiece you need is a 25mm or 30mm for lower magnification. This is how you will starhop to your target, before homing in with your 10mm. It is also good for the larger clusters and asterisms. I use the celestron 2x Barlow and wouldn't think of needing a 3x Barlow so can't comment on yours. Your 10mm is probably standard so upgrading it to either an 8mm or 10mm BST would be a great option. Those 2 eyepieces and a 2x Barlow is all you'd need in my opinion to get you going through beginner and intermediate observing.

[dweller25]

As others have said the BST Starguiders are a good value upgrade.

I think your scope is an F/5 so it has a focal length of 650mm.

A 25mm eyepiece will give you x26 (650/25) so that is good for deepsky.

For the planets around x160 would be good - that’s a 4mm eyepiece.

You did not mention the Moon but around x80 upwards is good so that’s an 8mm eyepiece.

So I would suggest you buy a 25mm and an 8mm and a x2 Barlow that both eyepieces will fit into.

That will give powers of :

25mm = x26

25mm barlowed = x52

8mm = x81

8mm barlowed = x162

There may be other options that suit you better.

[Ed the Fox]

I have a Skywatcher 130m  and have purchased the BST 8mm and 15mm and both are excellent eyepieces. I will be buying the 12mm and 18mm in due course. I still use the 25mm eyepiece that came with the scope as that's more than adequate. 

For me the BST eyepieces where one of the best purchases I ever made.

[Louis D]

2 hours ago, Ed the Fox said:

I will be buying the 12mm and 18mm in due course.

The difference in magnification between the 12mm and 15mm is only 15x (75x-60x) and 10x between the 15mm and 18mm  (60x-50x) for your scope.  Both would be negligible differences.  I usually recommend the 12mm and 18mm for a 75x-50x=25x difference which is noticeable, but you've already got the 15mm, so we'll work with that.

I would get a 32mm Plossl for widest field at 28x and a 5mm BST for 180x.  That would give you 28x, 36x, 60x, 113x, and 180x with exit pupils of 4.6mm, 3.6mm, 2.2mm, 1.2mm, and 0.72mm, which is a nice progression.

You might want to hunt down a 6.5mm or 7mm for 139x or 129x for nights that won't support jumping to 180x.  A barlowed zoom might fill this role:

 

[Ed the Fox]

@Louis D The 32mm plossl is a great idea as I do go hunting open clusters a lot and the 25mm just doesn't quite cut it.

I thought the 5mm BST may be pushing it a bit with my scope but you think it's OK?

[Louis D]

14 minutes ago, Ed the Fox said:

I thought the 5mm BST may be pushing it a bit with my scope but you think it's OK?

It would be right at the limit of what your scope can do.  You might want to explore the Barlowed zoom route to better explore the magnification limits of your scope and the seeing limits of your skies.

[Ed the Fox]

Cheers @Louis D I'll look around for those eyepieces. 

[Carl Au]

On 25/08/2022 at 18:37, cajen2 said:

Z is quite right: the BST Starguiders are one of the best VFM eyepieces around. In your position, I'd get a 25mm for wide views and for finding objects, plus an 8mm for good magnifications on the moon and planets. When you feel rich enough, you can start 'filling the gaps'. A cheap alternative to the 25mm BST is a Vixen NPL. I have the 30mm and it's excellent for the price (but don't get the lower focal length ones as they can have a problem with eye relief).

I concur 

[cajen2]

On 25/08/2022 at 19:55, Zermelo said:

I agree with the comments above about the Vixen NPLs for longer focal lengths. I have the 30mm, which works very well for me in an F/5 scope. The 25mm is possibly superior to the equivalent Starguider (and I see that FLO have now started to stock this focal length - except that it's currently out of stock!). Any shorter than that, I'd go with the Starguiders.

 

There's a bit of a trade-off in the fields of view though, Z. The BST is 60° whereas the Vixen is only 50°. Therefore, the actual FOV of the Vixen 30mil is almost identical to the BST, with the latter of course giving a higher mag . With both makes at 25mil, the BST has a wider field.

Edited August 29, 2022 by cajen2

[Zermelo]

1 hour ago, cajen2 said:

There's a bit of a trade-off in the fields of view though, Z. The BST is 60° whereas the Vixen is only 50°. Therefore, the actual FOV of the Vixen 30mil is almost identical to the BST, with the latter of course giving a higher mag . With both makes at 25mil, the BST has a wider field.

True, you're not maximizing your TFOV with a Plossl at 25mm.