Which eyepieces next?

[Rear Window]

Hi everyone, brand new here for a brand new year!  I bought a Skywatcher 150p F/5 Newtonian last year and only have the standard 10mm and 25mm plossl eyepieces it came with.  Christmas has come and gone and I'd like to upgrade my eyepieces.  I've seen a lot of different eyepieces, wide range in prices and a lot of attention on this forum to slow and fast telescopes.  What would people recommend for me?  My budget is around £400 so should I get one or two of the more expensive ones (Televue seems unilaterally praised on here) or get less expensive ones for more range in one purchase?  I had originally considered some Baader Hyperions but read here that they may not be great for my speed of telescope?

[Floater]

Welcome to the forum and welcome to the head-frying topic of ‘which eyepiece?’. You will receive a wealth of information, opinion and suggestions from people who are very knowledgable and experienced. You will be asked what you want to observe - solar system or deep sky; do you prefer immersive, wide fields of view or are happy with less ... and lots of other things.

My tuppence-worth would be to suggest you buy TVs and try to source them on the used market.

Happy hunting!

 

[Rear Window]

Hi Floater, thanks for the quick reply!  I suppose all beginners would say they want to observe it all but I'd prefer to start with more solar system viewing and move onto deep sky.  The TVs definitely stand tall on here, which end of the mm scale of eyepiece would be a good starting addition to the empty collection?

[Trikeflyer]

Pentax xw 10mm gets a good write up and might be a good fit for your scope with a decent 2x Barlow. I haven't used the Pentax xw yet but it's on my grail list of desidered eyepieces. I'm waiting for a used one to come up which doesn't happen often but does happen from time to time. I'd also suggest as I said above,  spending money on a decent Barlow or powermate to turn one eyepiece into 2. Of course as Gordon mentioned, televue used are also super (not that I've used one). 

[michael.h.f.wilkinson]

I have the 5, 7, and 10mm Pentax XWs and they are superb. However, they are not cheap. For travel, I use Vixen SLV 5, 10, and 15mm EPs and they are excellent as well, a lot cheaper, par-focal with the XWs, and essentially as sharp. They also have a very comfortable eye relief. Downside? Just 50 degree apparent field of view, as opposed to 70 in the XWs. If you can afford the XWs, by all means go for them, but the SLVs are a very good alternative.

[Victor Boesen]

I have been very happy with my Explorer Scientific 82 degree eyepieces.

[Alan White]

I have the same scope and confirm that the XW 10mm is excellent but a big chunk of your money.
I also have Televue Plossl's 25, 20, 15, 11 and they are excellent in the 150p.

The scope at f5 will demand decent eyepieces in my opinion, I have tried much cheaper and then sold them on.

XW come up used very occasionaly, I have waited nearly a year to buy the 10mm used!
New they are good value from FLO at £249 each.

One thing to be sure of, do you wear glasses?
Do you like long eye-relief?

[Rear Window]

Coincidentally Alan White, I just read about your purchase of that XW 10mm on the For Sale forum!  No, I don't wear glasses.  I'm not too familiar with eye relief, I've used the scope several times but don't really have a point of reference since it has only been whilst using the standard Skywatcher plossls.

[Alan White]

You may be better buying some decent but inexpensive next step eyepieces before stepping up to XW's to be honest.
The journey through the ranges of eyepieces I have taken over a number of years, you have to find what you like and don't like by observing with them.
Eyepieces are very personal things.

The Televue Plossl are good quality and very well made, but very good value when bought used.
I like them a lot and will not sell them although now duplicated with wider field of view eyepieces.
This is due to liking both images presented, they are subtly different as well as wider or narrower in view.

Eye relief is the distance from the upper eye lens to your eyeball.
The shorter it is the more you feels as if your eyeball will glue itself to the lens!  (semi-Joking)
I do not wear glasses to observe presently, but I do prefer a 15mm+ of eye relief.
 

[Timebandit]

 

Hi .

If it's your next step up I would go for a couple of BST starguiders 

They have about 18mm eye relief, fov of 60d and very good optics. And at £50 new will not break the bank. A very good next step up from stock eyepieces. And if you do decide to go up to the super fov , extreme high class optic expensive eyepiece in a year or so ,you will get most of your money back on selling the used starguiders.

I hope this helps☺

 

 

 

[Trikeflyer]

1 hour ago, Timebandit said:

 

Hi .

If it's your next step up I would go for a couple of BST starguiders 

They have about 18mm eye relief, fov of 60d and very good optics. And at £50 new will not break the bank. A very good next step up from stock eyepieces. And if you do decide to go up to the super fov , extreme high class optic expensive eyepiece in a year or so ,you will get most of your money back on selling the used starguiders.

I hope this helps☺

 

 

 

I agree with this as I have Starguiders and they perform very well. I have had them for a year or so and use them all the time. I recently invested in 2 inch 82 d Es 24mm and find it excellent, however, it's a big chunk of glass.  Now I want the Pentax xw 10mm. 

[Louis D]

Thanks to FLO's 20% discount when buying 7 BST Starguiders, you could get all 7 for about £280.  Aside from a very wide, low power 2" eyepiece, you'd be covered for most all of your observing needs.  As your skills evolve, you can start adding premium oculars in the focal lengths you use most as Christmas, birthday, Father's Day, anniversary and Valentine's Day gifts to you from your significant other.  Nothing says "I love you" like a £300+ eyepiece!

[Rear Window]

Thanks everyone, that is all really helpful!  I think I'll invest in the Pentax XW 10mm to replace my existing 10mm and either get a case/bag (to carry everything and to look longingly at the eyepiece cutouts ready for more) or a BST Starguider 25mm or 18mm.  I'll have more chance to save up for another Starguider quickly and would probably have to wait a long time for the chance to get a Pentax again. 

[alanjgreen]

In your scenario of owning just the freebee eyepieces, I would not blow my budget on just one expensive eyepiece!

What you really need is a set of 3 or 4 eyepieces covering a range of magnifications so you can try to match your scope to the conditions or object you want to view.

I would be looking to get eyepieces filling my magnification spread of x50, x100, x150 and x200.

I would not be looking to use a Barlow as it's just more glass and weight at the end of the day.

Your scope has focal length 1200mm (according to the spec)

scope focal/magnification = eyepiece focal

1200/50 = 24mm (a 24mm EP gives x50 magnification in your scope)

1200/100 =12mm

1200/150= 8mm

1200/200 =6mm

As said above get EPs with 15mm or more eye relief if you want a comfortable viewing experience with less eye strain.

I would buy one BST of a focal length that's useful (see above), use it and see how you get on with it. If you like it then get some more.

Have a look at second hand to save some money, in case you don't like the eyepiece.

Whatever you buy, keep all the boxes and packaging to make it easier to sell when the time comes to move up to another EP.

If I had £400 to spend I may also be considering moving to 8" aperture and some eyepieces all within that budget! What mount have you got? Can you swap out the tube for a bigger mirror or is it a dob?

An 8" scope gathers 77% more light than a 6" and will show you a lot more objects! (Just a thought, but I want you to get the most you can for your budget  This would make a bigger difference at the eyepiece than buying an expensive eyepiece! ). Of course, more storage space etc is also needed...

Alan

[Rear Window]

Hi alanjgreen, I'd be hard pushed to justify changing the whole scope as I've not long had this one!  My focal length is 750mm so based on your calculations it would be 15mm, 7.5mm, 5mm and 3.75mm for eyepiece focal.  The mount I've got is the Star Discovery AZ Go-To Mount.  I'm hoping to put these details in my signature once I've put enough content on the forums!

[alanjgreen]

1 minute ago, Rear Window said:

Hi alanjgreen, I'd be hard pushed to justify changing the whole scope as I've not long had this one!  My focal length is 750mm so based on your calculations it would be 15mm, 7.5mm, 5mm and 3.75mm for eyepiece focal.  The mount I've got is the Star Discovery AZ Go-To Mount.  I'm hoping to put these details in my signature once I've put enough content on the forums!

The star discovery is a nice scope

Beware of creating "balance" issues for your goto if you buy HEAVY eyepieces. 

Your motors will get noisy and struggle to move the scope if you get out of balance. The solution is to slide the tube up or down until balance is restored. Not sure if the tube is slideable on a star discovery?

[alanjgreen]

1 hour ago, Rear Window said:

Hi alanjgreen, I'd be hard pushed to justify changing the whole scope as I've not long had this one!  My focal length is 750mm so based on your calculations it would be 15mm, 7.5mm, 5mm and 3.75mm for eyepiece focal.  The mount I've got is the Star Discovery AZ Go-To Mount.  I'm hoping to put these details in my signature once I've put enough content on the forums!

You don't have to stick rigidly to these resultant sizes. +\- 1mm is ok. Just try to keep a spread of magnifications within your set.

Any difference under x50 is not really noticeable at the eyepiece so you would not be getting value for money having all your magnifications bunched up close together.

i would still get a nice 24mm eyepiece to give a nice low power view, useful for Milky Way in the summer and the largest clusters and nebulas (if I were you  )

750/24= x30 

then go up in x50 from here ...

x30, x80, x130, x180, x230 (you will likely get the least use from the x230 so leave this until last)

Speaking of which, you could also add a Castell 1.25" UHC filter onto your buy list for the summer nebulas and of course Orion at the moment. The Castell is a nice filter and good value at £40 from 365astronomy. 

Hth, Alan

[bingevader]

Reading your posts, I think you may have already changed your mind.

However, if you are only buying one or two eyepieces, may I be so bold as to suggest you don't replace the ones you already have!

Your latest set of calculations would suggest that you won't be.

The supplied 25mm really isn't that bad. 

I've compared it to similar TV and Meade plossls and yes they were better, but not blow your socks off better!

I'm sure others will disagree, but the 10mm might not be great, but its not a total stinker, especially in the centre, which with a goto is where your object should be!

Like me, it doesn't sound as if you've been able to do much observing this year.

Rather than blowing the whole £400 in one go on one EP or a whole set, why not, as others have suggested, buy one and see how you get on.

If you like them, you can then jump in with both feet!

[Rear Window]

Hi bingevader, yes we haven't had the best weather for observing.  Thought I might have ended up in Oz yesterday!  So if I kept hold of the 25mm and 10mm supplied, should I be aiming for smaller mm EPs as described above?  Say 5, 7 or even 15 or 20mm as an inbetween?

[alanjgreen]

29 minutes ago, Rear Window said:

Hi bingevader, yes we haven't had the best weather for observing.  Thought I might have ended up in Oz yesterday!  So if I kept hold of the 25mm and 10mm supplied, should I be aiming for smaller mm EPs as described above?  Say 5, 7 or even 15 or 20mm as an inbetween?

You need to calculate the magnifications of each and fit them into a range from x30-230 as above.

your 6" scope will not give good results above x230 (the aperture is small so at high magnification the image will get dimmer and dimmer)

Calc what the 25 and 10 give you?

Plot them within the range x30-230

Be aware that you don't want to get within x50 of what you have and look to buy something that fits into the gaps.

Its best to decide the magnifications you eventually want in your full set now and just buy single eyepieces that will eventually make up your final set OR you will end up with eyepieces too close together and need to start selling them or leaving them in your case unused.

first thing is to DO THE MATHS

[bingevader]

34 minutes ago, Rear Window said:

Hi bingevader, yes we haven't had the best weather for observing.  Thought I might have ended up in Oz yesterday!  So if I kept hold of the 25mm and 10mm supplied, should I be aiming for smaller mm EPs as described above?  Say 5, 7 or even 15 or 20mm as an inbetween?

Yep, that's what I did to begin with.

My budget was much less mind you, and I've built up my collection over a number of years.

At longer focal lengths, you need to make a bigger leap to make a significant difference in the magnification.

As you know, your 25mm EP gives you 30x, but a 20mm EP would only go up to 37.5x, so I'd go for the 15mm at 50x if you were going to fill the gap.

At the over end, with shorter focal lengths, small changes make a big difference in magnification.

The 7mm will give 107x compared to your 10mm at 75x and the 5mm will give you 150x.

So either of those would be a significant difference over the 10mm.

[alanjgreen]

21 minutes ago, bingevader said:

Yep, that's what I did to begin with.

My budget was much less mind you, and I've built up my collection over a number of years.

At longer focal lengths, you need to make a bigger leap to make a significant difference in the magnification.

As you know, your 25mm EP gives you 30x, but a 20mm EP would only go up to 37.5x, so I'd go for the 15mm at 50x if you were going to fill the gap.

At the over end, with shorter focal lengths, small changes make a big difference in magnification.

The 7mm will give 107x compared to your 10mm at 75x and the 5mm will give you 150x.

So either of those would be a significant difference over the 10mm.

I have to disagree a bit with the above. Not wanting to offend anybody by this  

If you have a x30 eyepiece then also having a x50 eyepiece would not be a significant difference at the eyepiece. I would not want both x30 and x50 as a beginner.

skywatcher have given you a 25 and a 10. The 25 gives x30 and the 10 gives x75 that's a gap of x45 which is significant to notice at the eyepiece (as you will have seen).

if it was me I would jump from x75 to around x125 as a next step. So I would be looking at a nice 6mm with decent eye relief. Looking at FLOs website I do not see any 6mm...

BST do a 5mm which would give x150, they also do an 8mm which would give x94. If you keep the 10 then I would not get the 8.  The 5mm would be ok.

celestron xcel is available in a 7mm (these are decent 60 degree long eye relief EPs at £69 from FLO). The 7 would give x107 in your scope this would be a gap filler between the x75 and the x150 BST.

So, now you have x30, x75, x107, x150. 

If you like either/both BST and XCEL then you can add more at the higher power around x200 later or maybe replace the basic 25 & 10mm later too.

https://www.firstlightoptics.com/celestron-eyepieces/celestron-x-cel-lx-eyepiece.html

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

Alan

[Rear Window]

Thank you everyone for your feedback, I've learned a lot!  I've decided to combine what you've all told me, especially about ensuring some range of EPs for different magnifications.  I've gone with the Pentax XW 3.5mm which is under full budget.  The logic being that it will provide the higher end of magnification to compliment what I have with less magnification.  If it doesn't suit or I don't like it, then I can sell it on and try the BSTs but because I've saved a bit I can still get one later in the month.  I'm happy to take this hobby slowly, it started slowly so I am fine with gradually progressing my collection and trying new things.  That filter does also appeal though!

[happy-kat]

I can't see exit pupil mentioned. 10mm gives an exit pupil of 2mm on your telescope anything smaller could see your head waggling to place your eye exactly where it needs to be to see the image, though maybe not everyone is as bothered by this as me. DSO objects are easier to look at using mid range power I find, my 16mm eyepiece is my most used in my 650/130. You don't know yet if you like twist up eye cup or rubber topped eye cups etc.

[happy-kat]

When you turn binoculars upside down you will see a circle of light on each side, this is exit pupil it is where your eye would be to see the image. Eye piece focal length/focal ratio of telescope.