130pm Eyepieces advice

[Bathurst]

Hi all, I read the brilliant sticky post on Eyepieces and did post this in there but figuered people might skim over it:

Would just like to check that I'm buying correctly before hitting the Purchase button!

Sky Watcher 130pm scope owned:

To Buy - Skywatcher 2x Deluxe Achromatic 1.25" Barlow

To Buy - Skywatcher SP Plossl eyepieces 17mm and/or 20mm

I'm not rich so cant afford the more pricey models, but not sure if there's a vast difference between 17mm and 20mm? bearing in mind they are out of stock of the lower EP anyway, not sure if they are both worth getting or just getting one now and a 25mm and lower mm later on? Complete beginner so doing the obvious Planet hunting and Moon stuff currently.

Thanks all

[Schorhr]

What is your total eyepiece Budget?

Quality wise the cheap 2x achromatic barlows probably Don't differ much or come from the same factory anyway.

I have one from meade and one from seben (their eyepieces are decent while their telescopes have had bad press).

Do you own the stock 10 and 25mm eyepieces?

For planetd you should get a 5 to 6 mm eyepieces and a barlow, but don't get Plössl with such short focal lengrh as the eye relief is too short to comfortably use them.

Budget solutions are the 66 degree swa eyepieces, around 27£ shipped, better at f/5 focal ratio are the tmb or bst planetary eyepieces (around 40£).

The seben/orbinar barlow costs around 13£ shipped.

Budget-budget solution:

30/32mm Plössl for the widest field possible on 1,25" focuser (or don't, stock 25mm eyepiece will be sufficient for a while, the 30mm 12£ Plössl require a diy eyecup and the 32mm brand name Plössl are good but not cheap)

6mm swa 66 degree aparent field of view eyepiece

http://m.ebay.de/itm/140717462903

better the bst or tmb/hr planetary, though they cost a bit more. Their ouer field is sharper on f/5, the 66deg eyepieces are still pretty good, at least the 6mm, at 20mm it's more noticable

2x barlow

http://m.ebay.co.uk/itm/200607942106

A 30mm and 6mm plus barlow would give you about

22x, 44x, 108x, and 216x for good conditons, great for planets and such.

Together with your existing 10x this is a pretty decent magnification palette, but of course later on a few gaps should be filled.

I have a 8mm tmb hr also as it is a bit more versatile under not-so-good conditions; So depending on lightpolution at your location there is also a 9mm66deg eyepiece.

To sum it up, higher magnification 260-200 is possible under good conditions and when the telescope is well collimated. Saturn, Jupiter and moon look stunning. Despite the loss of contrast with a cheap barlow, it's a good solution as a 3,2mm hr planetary is awesome but at the beginning you won't be able to use it as much (seeing conditions, planet positions) as a good overview or mid range eyepiece.

At the Moment I use for my 130/650:

30mm plössl, 20mm erfle, 8mm hr planetary, 6mm66deg, 3.2 and 2.5mm planetary as I got those cheap, and a 2x Barlow.

The Most use get the 20mm erfle (similar afov to the 20mm66deg) and the 8mm, and the 3.2mm when the seeing is okey.

If I had to choose now I would buy the 6mm erfle again it's a good budget eyepiece if you can live with the slightly worse view then the tmb hr.

[bingevader]

Do you currently own any eyepieces and roughly what is your budget?

The Vixen NPL eyepieces seem to be reasonably well thought of budget eyepieces on the SGL forum.

But as Schorhr has said, the eye relief (how close you have to get your eye to the eyepiece to view anything) gets a bit tight in the lower focal lengths.

As you have found out, a Barlow would be a good option if you are on a very limited budget, so you can in effect double your eyepiece collection.

I which case, I'm not sure I'd get a 6mm eyepiece as you'd only be able to use the barlow on it on very good nights.

Perhaps an 8mm or 10mm would get better use.

I'll stop there, as without knowing budget and what you already have or not, it's difficult to advise on what would give a good spread of eyepieces for the minimum out lay.

Cheers

[Bathurst]

Hi thanks for the quick responses, please bare with me I'm totally new so still trying to understand all the schematics invloved

Firstly Budget, actually forgot today is Pay Day which is nice and increased my spending somewhat (after figuring out this months direct debits!)  £125-£150 cant do anymore than that really and would like to spread that over 1 Barlow and 2 or 3 Eye Pieces if possible, maybe more if cost & quality allows.

Secondly Eye Pieces owned, just the two I got with the Scope: Super 10mm and a Super 25-Wide Angle Long Eye Relief

Thirdly...and this is something I've only read about today and come to think of it it's quite important..is that I'm 36 and dont wear glasses

[AlexB67]

If you main interest is planets for now and the moon that barlow will work quite well. I have the same barlow you quoted. That being said, it will not make up for, or get close to what even a cheapish sky-watcher 6mm UWA will deliver if you compare it to barlowing the stock 10mm eyepiece ( if you own that already ).

You may find that because of fairly small aperture, but not to be sneezed at 130mm, when it comes to DSO viewing particularly if you got into that later on, faint targets like galaxies the SW barlow will show its short comings, due to quite a loss in contrast and light loss in general. That being said, I had quite satisfying views with in brighter targets, Moon, Jupiter, Saturn, and so on.

In my scope ( same aperture as yours ) I find magnification is not everything, or perhaps depends a bit on the observer, but for me personally to give an example. I prefer viewing Jupiter through my 8mm BST, the best higher mag eyepiece I have, then followed by the 6mm UWA which has in actual fact higher magnification, but the image is not as crisp, colourful. The moon is very bright anyway, so this is where I use the barlow mostly, even on the planets not I do not use it often these days.

So, where am I leading with all of this, well one view, and it is just that, a consideration may be to buy two eyepieces instead of 2 eyepieces and a barlow to begin with ( depending on budget ) or even one for that matter instead of buying in one go, and see how you find it, perhaps consider getting a barlow a bit later and more eyepieces and save a bit more. Hope that helps a bit

edit: missed your last post but anyway, now you got budget in there.

[Schorhr]

Rule of thumb is to get something with an exit pupil ->(eyepiece_mm devided by telescope_focalratio) between 5-7mm  and 0.5-0.6mm.

Smaller = Too dark

Larger = Depending on age, eyes and light pollution the iris won't open up more then 7mm, in urban sky conditions less (5-6mm)...

Then there is air turbulences, seeing; Either in the atmosphere or caused by viewing objects over roof tops for example that are warmer then the surrounding air.

Here, 200x works quite often. And I would not want to miss such high magnifications as it's stunning to view planets, double stars and the moon. But  as I mentioned and bingevader explained, most of the time seeing conditions may limit how high you can magnify anyway.

The main advice: Don't buy too much too fast. Use your telescope and equipment, and then get another eyepiece or barlow.

Don't get one of those Plössl-Case sets as you won't use two thirds  of them anyway ;-) 

Do you use Stellarium?

Set up your telescope there. Sure, it won't show a realistic view regarding the lack of color on deepsky objects and darkness of faint objects, but it will help you decide what eyepieces you want to get regarding magnification and field of view.

As a quick example, a 6mm 66degree wide angle eyepiece for 32euro/27gbp will show roughly as much as a 8mm Plössl eyepiece. The wide angle view of stars and moon are stunning. Plössl have about 50 degree  apparent field of view, other designs around 60 (tmb, bst), 70 (erfle, swa) or more (82-120 degree, "budget eyepieces" in that area are the explore scientific, but some may cost as much as your telescope or more).

Plössl and older eyepieces like Kellner and Hyugens (30-40 degree afov) have about the eye relief of their focal length. Even without glasses under 10mm it get's pretty anoying; I don't wear glasses either but using my 4mm Plössl is nearly impossible. 

A nice, relaxed view helps a lot when trying to see faint galaxies. Also the wider field of view helps keeping planets in the view at higher magnification, especially without tracking.

As the  17eur/14gbp barlow is cheap, it is a great way to increase the range of your existing eyepieces. I am normaly not a fan of barlows as better one may cost as much as one or two good entry level eyepieces, but at that price it's a good way to find out what magnifications work best for you.
There is a 3x meade for 19eur/16gbp or so, but the color fringe of the 3x barlow is more noticable. Still usable.

More glass means more optic errors and less contrast. Of course modern eyepiece designs have barlow elements too, but they work better as they are calculated for their specific lens setup.

Stay clear of zoom eyepieces. The seben/orbinar 24-8mm seems to be better then the one I have (ts 21-7mm) but still both have a verrry narrow field of view at the low magnification. In that price range, get two or three of the mentioned eyepieces instead.

Of course brand names may have better lens coatings, black coatings and so on, but as a rule of thumb the order of good entry level eyepieces would be

Hyugens, Kellner 30-40degree afov, !not advisable 5-10gbp

Plössl 50-54 degree afov 6-12gbp no-name, up to 30gbp as brand name 

SWA or whatever-lable 66degree  eyepiece, 27-40gbp

58deg TMB HR-Planetary 38-50gbp

60deg BST Eyepieces 45-60gpb

Explore Scientific 68, 82 degree eyepiece depending on the ep they can cost 100 and up

[bingevader]

Ok! Firstly, if you are totally new to this, then maybe a bit of time to get used to the 'scope with the EPs you have may give you a better idea of what you want to get out of this hobby. If you've a local club, it would also be a good idea to check them out too.

The 10mm and 25mm EPs will definitely do for a while, they're not that bad, just not great.

However, with that budget, you're definitely into BST Explorer territory! I know it's a well known auction site, but the EPs are brand new from a very reputable seller and are highly rated (even in the Sky@NIght magazine!). He also does a Barlow, but I don't know what it's like.

You are also just about into Maxvision territory! These are re-brands of expensive Meade EPs. The 16mm, 20mm, and 24mm 68^o Okulars would all be in budget.

As for a range of EPs, the 8mm and 15mm are very popular and would nicely fill your gaps. If you got a barlow, that would take the 8mm up to 4mm and around 162x magnification.

Hang fire for a bit though and see what others suggest.

Cheers

[Bathurst]

Thanks very much for the responses all it's very much appreciated and welcome

I'm gonna re-read your posts to make sure it all sinks in and continue browsing the threads on the forum as I am doing currently, even though I'd like more time I'd like to get the new EPs (abbriviation learnt!) sooner rather than later, mainly because Xmas is around the corner then New Year expenses meaning the next chance to buy wont be until February. That means missing out on 3 months of Winter Skies and the all important Comet Ison in December (fingers crossed on that one).

I do have Stellarium but have yet to set it up correctly, I'm going to contact my local club (ADUR Astronomical Society) soon as face-to-face expertise will aid me greatly (not that this site does'nt but you know what I mean!), but please if anyone else has experiences post below and I shall cram it all in before I spend, Many Thanks again

[Schorhr]

Good luck and don't worry it gets less and less confusing with time. Just don't get a short focal length plössl and everything will be fine :-)

There is a lot to explore out there, and there is no wrong tool.

[Bathurst]

I've ordered the Barlow as quoted in the first post and the BST 8mm Duel ED eye piece, I'm gonna hang fire on another EP just for the time being so I can get more used to the new one and current stock EPs, then I'll purchase another one or two when I know what I'm missing.

Many Thanks for all your help again, not just to the posters who took the time to reply directly here but all the other replies to other threads, it's very much appreciated

[bingevader]

Good choice, haved fun.

Cheers