Which eyepiece for planetary viewing with SW 130

[topdude]

Hi, i need advice on which eyepieces would work well with a SW 130 Newtonian 650mm f/5 for planetary viewing.

I know there is a theoretical maximum magnification of approx 300x for this scope and i have read that some eyepieces are not ideal with fast apertures.

So any advice would be much appreciated.

Budget is low so less than £100 would be good.

Thanks.

[great_bear]

i have read that some eyepieces are not ideal with fast apertures

Yes - that's unfortunately true for nearly all "classic" eyepiece designs.

There is also the problem that a classic eyepiece which resolves the most detail in your scope - a 4mm one - has very short eye-relief (you have to press your eye right against it) and as such is very uncomfortable for normal users and unusable for spectacle wearers.

However a Barlow lens in combination with a longer-length eyepiece cures both problems.

So this leaves you with two choices:

1) A classic eyepiece like an Ortho, a Plossl or a Monocentric in combination with a Barlow.

2) A more complex 4mm eyepiece that works by (effectively) having the Barlow built in.

Some purists don't like using complex, multi-element eyepieces for planetary use, citing transmission losses because of all those glass surfaces. However, at high powers with an F5 scope like yours you'd need to otherwise use a Barlow lens anyway (which has at least two elements) so I feel that it pretty much evens out.

The "Standard" Barlow that comes with some Sky-Watcher scopes isn't very good at all - however some other Sky-Watcher scopes come with the so-called "Deluxe" Barlow, which is better.

As you've discovered already there are many, many options. If you're on a budget, in my personal opinion it's better to buy good quality eyepieces second-hand than second-rate eyepieces new.

A 4mm will show all the detail your scope can resolve (a good choice for planets and lunar) and around 2.5mm provides higher magnification for star-splitting.

I'm sure people will offer lots of suggestions, but if you got a Baader Hyperion 5mm (£99 new or £60 second-hand) and purchase both "fine-tuning" accessory rings at £10 each, then you'd have an eyepiece that you can customise to provide you with the following magnifications: 130x, 160x, 200x and 250x which will at least give you experience of how far you can push your scope under different conditions.

[TheThing]

Really not much point in spending £100 on an EP if you're just starting out. You can get some great 2nd hand EPs on this very board. Plossls will (despite what might be suggested) give you good results, even with a fast scope.

I wouldn't even bother with a £60 Baader TBH. For £60 you could get 2 or 3 plossls or orthos 2nd hand, giving you a range of magnifications.

[Starflyer]

I started with the same 'scope that you've got

My first upgrade was a 26mm 4000 series Meade eyepiece, I picked it up for ~£25 second hand and it was a massive improvement over the supplied 25mm EP. The supplied eyepieces aren't great and you don't have to spend big money to see a big improvement.

I'd suggest looking for similar second hand eyepieces (the Meade 4000s are great value) and add a better x2 barlow such as the TAL barlow. If I was doing it again then I'd probably look out for some second hand Meade 4000 series - 32mm, 26mm and 9.7mm with a TAL x2 barlow. You'll probably get all of these for around your initial budget or just over, just keep looking on the For Sale board here and AstroBuy&Sell, they come up quite regularly.

[Whippy]

I think you may want to hold off going for such a high power eyepiece. It's not very often at all that you're able to reach your scope's theoretical maximum and so buying an eyepiece that enables you to do that won't get used that often.

I'd go for an eyepiece in the reigon of 6-8mm, you'll get a whole lot more use out of it.

Tony..

[Mark at Beaufort]

I totally agree with Tony (Whippy) over getting high powered EPs. The suggestion that you obtain a 6mm to 8mm is very sound. I am sure a S/H Plossls would be a good purchase and you could obtain a better 2x barlow in the future.

Mark

[great_bear]

Really not much point in spending £100 on an EP if you're just starting out.

Depends on the eyepiece... Second-hand eyepieces tend to keep their value so it's no different from keeping money in the bank really.

You can get some great 2nd hand EPs on this very board.

Agreed - second-hand is definitely the way to go, and this board one of the best places to find 'em.

Plossls will (despite what might be suggested) give you good results, even with a fast scope.

Again, depends on the eyepiece. Some Plossls (Televue / some Meade) are OK, but many cheap Plossls don't fare so well at all.

I think it's especially important when starting out to work with quality equipment. "Making do" with comet-tailed stars nearly put me off astronomy for good - until I learnt what was going on and how to fix it.

[great_bear]

I think you may want to hold off going for such a high power eyepiece

Yes - 300 isn't going to be used much - but I can't help thinking that 8mm is a bit on the weak side? That's only 80x magnification with this scope. I know our weather's bad, but it will bear more than 80x magnification.

I use 150x regularly on the moon and sometime the planets (even from North London), dropping down to 120x or less if the atmosphere is particularly bad.

As for higher magnifications (in my Mak 180) - of 180x / 216x - surprisingly I use these almost every time I go out, regardless of less-than-perfect "seeing" - since I particularly like looking at double stars and distant clusters, and - with a deep red #29 filter - the moon bears much higher magnification.

Low-power deep sky is so fashionable these days I wonder if people forget that there's lots of high-mag highlights to see which don't require perfect seeing or pollution-free skies.

[topdude]

Wow, thanks for some brilliant replies, i have a Tal 2x barlow so i think i will try that with one of the suggested eyepieces to give better eye relief and see how that works out.

Thanks again

[great_bear]

Ah... Well... Since you've already got a good Barlow, then I thoroughly recommend trying out some "Circle-T" Orthos (known as University Orthos in the USA).

You can pick them up for £25 second hand, and they are world-class in performance terms.

A 9mm and a 7mm - in conjunction with your Barlow - are well worth a spin, and you can sell them on if you don't like them (unlikely) and for the same price you paid for them.

[superjody]

hey guys, reet im very new to this with alot to learn, still have to figure out all different magnifications etc

anyway, iv got a skywatcher 130 with the standard eyepieces and had a clear night for a while tonight in manchester and jupiter was clear and bright. i got it into focus using the barlow lens and the 10 and 25mm eyepieces (forgot which got me in closer). i could see the moons and just about make out the different colours on jupiter but they were very very very faint.

what eyepiece would be suitable for getting closer or making it clearer to see?

im finding that the barlow gives false colour slightly around the edge

cheers

Jody

[great_bear]

Hi Jody,

Assuming a reasonable-quality telescope such as yours, here are some things that beginners typically don't know, which can lead to eyepiece purchase disappointment:

a) The single biggest contributor to planetary fuzziness is the atmosphere. Ideally, you should have good weather, your planet should be as high in the sky as possible, clear of rooftops, and check on the internet that the jetstream is not overhead since this will cause views to appear out-of-focus.

Atmospheric conditions frequently cause Jupiter to have a coloured fringe - irrespective of the quality of eyepiece.

c) The above issues form a "brick wall" over which you cannot magnify without simply getting a featureless blob.

d) This maximum planetary magnification level will vary significantly from day-to-day from less than 120x to over 200x

e) For reasons which are not entirely clear, Jupiter doesn't seem able to accept quite as much magnification as other planets.

f) The moon is able to accept more magnification than the planets.

g) You can achieve much more successful high-magnification views of the moon by observing through a "#29" dark red filter.

In summary, you will see significantly more difference day-to-day as a result of changing atmospheric conditions, than you will by using a new eyepiece. Having said that, there is no denying that high-quality eyepieces are a delight to use.

Casting aside from discussing "collectors eyepieces" (such as "Zeiss Abbes") and focussing (no pun intended) on readily accessible products in the shops, your best planetary views would arguably be achieved by having Baader Genuine Orthoscopic eyepieces, and a Celestion Ultima Barlow. Starts to get expensive though.

For a lot less money though, second-hand "Circle-T" eyepieces (sold as "University Orthos" in the USA) are undoubtedly the best price / performance winner at around £25 second-hand, and provide views almost indistinguishable from the BGOs. They are beautifully well-made. I am not sure what the best second-hand Barlow would be though.

If you observe with spectacles however, you may be better off choosing good quality "long eye relief" planetary eyepieces instead.

[nitram100]

Second hand circle T orthos are amazing value for money, i have a 12.5mm and 9mm, they are by far my favourite eyepieces, great on globulars aswell.