10" dobsonian suggested eyepieces

[Norfolk star gazer]

Hi, I am very new to astronomy and bought a 10" skywatcher dobsonian at the weekend.

I am after some advice on what eyepieces to buy. I mainly want to look at planets and deep space objects. I'm completely baffled by the array of different eyepieces you can buy and was wondering if the SkyWatcher Planetary UWA Eyepiece range was any good and what sizes would be good for my scope and what I want to do? I would rather buy cheap ones at this stage and that more expensive ones as time goes by.

I would like to buy a couple and assume that there's no point in buying two that are only a mm apart (or am I wrong) and does this depend on what planet / DSO you are looking at?

Jason

[ronin]

First and almost standard question: What budget are you looking at per eyepiece and I am guessing 2 eyepiecce from what has been mentiioned, any chance of 3??

10 inch is probably f/4.8 or something, but less then 5.

You may be wrong on 1mm difference, things are sort of critical at the small end.

The BST's (£49) should work well, they come in 5mm, 8mm, 12mm (at the lower end),

Nice eyepieces but for planetary viewing the gaps may be a little big, or not.

The Celestron X-Cels (£59) perfom similar and they come in smaller steps: 5mm, 7mm, 9mm, 12mm.

For planetary these are likely better, more selection.

Problem is you say mainly planets and DSO's, what else is there?

DSO's are different to Planets.

Not 100% sure about how goo a 5mm will be, 7mm and 9mm sjould be good on planets, but you need a 25mm and one in the middle for DSO's.

Now at 4 eyepieces however.

If DSO and Planets I guess that an 8mm and 25mm BST will do you well.

Equally a 7mm and 25mm X-Cel good.

If planets take precidence a 7mm and the 12mm X-Cel, nice balance.

For greater magnification you will want the 5mm eventually.

I took the "simple" option, I bought all the BST's.

[kev100]

Hiya,

I have the same scope as you, and, as you mentioned preferring cheap at this stage, you could do worse that the 9mm revelation plossl. It's a pretty good (and cheap) EP, and will give 133 times magnification – and on Jupiter and Saturn that may well be as much as the seeing will handle. I haven't tried the SW planetary UWA, but I see they're available form FLO, so they should be able to give you advice on these, but I wouldn't go higher than 6mm, as the seeing in the UK just won't deliver at that magnification. 

I have a 6mm William Optics EP and more often than not the 9mm plossl gives a crisper, though smaller, view. On nights when the seeing is very good, though, the 6mm is pretty awesome!

Kev.

[ronin]

P.S. Where in Norfolk?

There are a few clubs around the area, one may be close.

[Norfolk star gazer]

Hi Ronin,

Thanks for the advice. More to take into consideration.

I would consider 3 or more and am willing to spend a couple of hundred as long as they will cover most viewing needs.

As for my comments about wanting to view planets and DSOs, I only wrote that as when I was choosing what scope to buy, people said that it depends what you want to view. I thought at the time that it was a strange question.

I live in Aylsham, Norfolk and have been in touch with the club near Wiveton and also have friends who go to one in South Norwich at Seething. The Wiveton one is nearer (30 mins drive) as opposed to the other one (over an hour), but just my luck the nearest one is a very small group.

[Norfolk star gazer]

Hi Kev

Thanks for the info.

It appears that it's not a case of having just a few EP's then but a multitude to cover all eventualities.

[Norfolk star gazer]

Ronin, I see that there is a 2.3mm version of the celestron. Is that one to consider?

Also, can I ask why did you go for the BSTs instead of the Celestrons?

I see the Celestrons are £80 online so would consider 3 of them, but there are 7 in the range (so many choices)

[Norfolk star gazer]

Ronin,

Just re read your original reply about getting a 7, 9, 25 and one in the middle, so it's looking like a £320 spend (eventually) if not more.

Might start with a 7, 9 & 25.

[ronin]

Best to say forget the 2.3mm, I cannot really think of a scope it would work in and I have shorter focal length ones then the 10".

X-Cels are £59 at FLO so anywhere asking £80 is pushing their luck and hoping to gain from it.

Think I heard of the BST's first and I wanted a 5mm for a small scope, so I bought 2 BST's and 2 TMB (clones).

Another aspect was at the time Celestron did not really produce "good" eyepieces, presently some of theirs are produced by Barsta who make the BST's.

BST's were simply very good, so I bought another 2, then got impatient and got the final 2.

When the 3.2mm BST came out I got one of them - mainly to have the lot.

Never really used the 3.2mm, not much chance since I got it and for whatever reason when I have taken it out to be used never managed it.

If the BST's came in 4mm, 5mm, 6mm then the others I would not bother with anything else. But they don't.

Aylesham = Altair Astro, have you looked at their Planetary eyepieces?

5mm, 6mm, 9mm and 12.5mm all at £45 ?

I do tend to stick to a set - prefer to keep them parfocal - if you did not then the BST's at 8mm, 12mm and say a William Optics 6mm planetary.

There are so many possibilities.

[kev100]

Hiya,

Yep, definitely a case of having a spread of EPs. Seeing can be so variable, and different targets respond differently, too. I really wouldn't go any shorter than 6mm, and I'd be wary of spending over £300 on a set of EPs without trying them. I've tried BSTs in the 10 inch Skywatcher, and I found the coma/distortion around the periphery to be off-putting. Others find it OK. I also experience coma/distortion around the periphery of my MaxVisions, but it doesn't bother me ... it's a very personal thing.

I'd really recommend you stick with the stock items until you've had a chance to try some others and see how you get on with them.

Kev.

[Norfolk star gazer]

Ronin,

Altair is my local shop and I met the guys at a recent star party in Kelling and was intending to buy a more expensive set up (nearly double what I've paid) from them, but decided against it.

I know that they do eyepieces and I only emailed them today to say that I would pop in, but they never seem to be open when I go there.

Will have a look at the website and see if I can get them online.

On a positive note, I got a good look at the moon, Venus and Jupiter last night with my stock pieces that came with the scope (10mm and 25mm) and a hours viewing tonight before the clouds moved in

[Norfolk star gazer]

Kev,

I will see if my local shop is willing to let me try a few before I buy and failing that, I will ask someone I know that has a range of pieces if I can borrow some, but I know that some of hers are expensive £100's.

[Qualia]

For general DSO viewing, I feel you don't need more than three eyepieces. For my 10" f5, for example, I generally observe and sketch with wide field (72º) eyepieces offering around 50x, 90x and 125x. Coupled to a decent Barlow (or Powermate), you've then got  50x, 90x, 100x, 125x, 180x and 250x which should suffice for most clusters, galaxies, nebulae, and general lunar and planetary work.

If it took your fancy, for white light solar viewing the 50x will also be ideal and all you'll need is Baader's Visual Solar Film from First Light Optics which is extremely effective and cheap.

If you decide later to really get into planetary and lunar observation, you will probably find that it helps to have a good run of high power eyepieces. Depending on the evening, seeing condition etc, even the difference of just 1mm in focal length - about 10% to 15% difference of magnification - can be surprising. But the good news is the eyepieces themselves do not need to be widefields, so you can buy cheaper Orthos and there's no hurry to build the collection all at once. Again, by way of example, in my own case if I fancy doing a bit of concentrated planetary, lunar or 'getting-in-there' observing of a deep sky object, I use 5mm, 6mm, 7mm, 9mm and 12mm Orthos and an 8mm and 11mm Plossls. 

There's certainly no need to go spending loads of money to get decent eyepieces and on this account your best bet is to scan the secondhand market. Nevertheless, extracting budget from the equation and purely looking at some of the the most popular eyepiece options available the following seem to get rave reviews time and time again:

Tele Vue

Pentax

Explore Scientific ES68, 80 and 100

Meade 5000 UWA

William Optics UWAN's

Vixen SLV

Skywatcher Nirvanas

Orthoscopic like Baader's Genuine

X-Cels LXs

BSTs

I cannot comment on most of these eyepieces mentioned but at the end of the day, I feel it makes more sense to not buy a load of eyepieces but instead, save for two really cracking, quality glass eyepieces with a magnification around 90x and 125x, a decent low power eyepiece and Barlow that will last you many years.

[Norfolk star gazer]

Might be a stupid question, but how much difference would I see between my stock 10mm EP that came with the scope and say a decent 9mm BST, Celestron or Altair when viewing planets.

I'm thinking of buying 1 new EP a month and would like to start with one that will be a lot better than I already have, so would like the first one to give impressive views.

Or should I go lower like a 7?

Just to clarify, is it lower EPs for planets (10 or less) and higher ones for DSO (25+)?

[ronin]

The 8mm BST or 9mm X-Cel should give a much improved view.

Not sure how good a 7mm will be, really it should be fine.

It is somewhat longer then my normal minimum rule but the 8mm would be "easier".

The 8mm BST gets good reports and also seems one of the most used, not too much magnification but enough and therefore the viewing is generally crisp and sharp.

From Robs post he says:

"I use 5mm, 6mm, 7mm, 9mm and 12mm Orthos and an 8mm and 11mm Plossls."

That is close to 1mm increments, and the BST's are good but they do not have the smaller steps that the X-Cels do, X-Cels go in about 2mm increments. Useful for planets. For DSO's you could likely managed on a 25mm and a 12mm or the 9mm.

Planets are bright, so they have the light to enable magnification. DSO's are genarally dim so magnification makes them dimmer, so a long eyepiece keeps the magnification down and so a bit brighter. M42 I suppose semi-breaks that idea.

Also some DSO's are simlpy big, M31 being the prime example. That needs about 20x to get it all in.

I suppose the decision is which brand first.

Not sure how mixing BST's and X-Cels appeals, BUT be warned if you do that then you could end up with a set of BST's and a set of X-Cels. :grin:

One idea is just get the 8mm BST as a single item for now - least cost of the BST/X-Cel. Then look round with a bit more time at other eyepieces. There are several out there now and take longer to make up your mind. If you have something to deliver a good view it takes the pressure off a bit.

There is no real simple answer, as I suspect you are starting to realise.

[AndyWB]

With my Skyliner 250px, my most used eyepiece is my lowest power. I tend to use the Maxvision 28mm or an Vixen NPL 30mm. If you can get one, the Maxvision is much better - though the Vixen NPL is much cheaper. Plasticky too, but works well.

At the other end, I use a Vixen SLV 6mm as my standard planetary eyepiece. It isn't the widest field of view, but it is crisp, and gives x200. I find my 5mm BST too much - it all gets a bit soft. I'd say 6-8mm should be as short as you go.

In between, I reckon a 12 or 15mm BST would be good.

All that said, the 6mm Vixen SLV and the 28mm Maxvision are my most expensive eyepieces. An 8mm BST would be a fair bit cheaper, and you could think of something shorter later. (But seriously, a good low power eyepiece is great!)

[Norfolk star gazer]

Thanks for all the advice.

I have taken the plunge and just ordered a Celestron X-Cel 9mm and should receive it by the weekend.

The first step to a fortune spent on EP's

I'm assuming that this will be a lot better than the Super 10mm that came with the scope?

I also got a 25mm wide angle long eye relief one with the scope and assume that the 25mm Celestron will out perfom that one?

[ronin]

Should see a good improvement, report how it goes.

People have asked about the BST's and X-Cels but there are no real number of comparisons simply I suspect because they are similar enough that you get one or the other but not both. That is/was one of the problems of someone asking which is best, A or B? People tend to have A or have B but not both, so can only say how they find 1 item.

The 25mm again should be better but not I suspect by as much, although that will depend on what the supplied 25mm actually is. If the supplied is a Huygens then it certainly will, if they supplied a plossl then an improvement but not so great. In the middle sit MA's. Your scope is reasonably fast and so the X-Cel's are better suited over any of those mentioned.

What is written on the supplied 25mm?

Besides "25", the 10" can be supplied with a variety of eyepiece designs.

To me the one aspect of simply getting eyepieces is that you know what it is that you have.

[Norfolk star gazer]

The 10mm just say's SUPER 10 and the 25mm WIDE ANGLE LONG EYE RELIEF.

No brand names or clue to what they are and the names are on stickers rather than written on the EP, so I am assuming that they are just very basic ones and wouldn't expect them to provide quality ones as part of the package.

When I viewed Jupiter on Sunday night with the 25mm, its moons were small dots and Jupiter was a few mm's wide and I could just about make out the bands. With the 10mm is was a mm or so bigger and a bit clearer. Does that sound about right for basic EP's or what I can also expect with the 9mm Celestron?

[Norfolk star gazer]

Looking at some online, I think that the 10mm is a MA.

I guess that if you stick to 1 brand of EPs that it's best practice to use the same brand when buying barlows?

[John]

I think both the stock eyepieces are modified achromats, similar to the kellner design. The 10mm X-Cel LX will be a notable improvement.

You don't need to stick to the same brand for all your eyepieces / barlows. Cherry picking the best from the affordable options seems to work well although it does require a bit more research to find the "gems"

[Norfolk star gazer]

Thanks

I bought the 9mm xcel and was looking at the xcel Barlow, but that's over £70.

The skywatcher is around £30. Is that a decent one as barlows go?

I don't want to buy good EPs, but then lose the benefit by using a inferior Barlow!

Looking at getting a 25mm excel maybe next month and hoping that it will outdo the stock ones

[Norfolk star gazer]

As well as the 9mm celestron x-cel, I've just bought a cheap celestron 2 x Barlow and 4 basic EPs (4 , 8, 12.5 & 20)

So I will now have :

4, 8, 9, 10, 12.5, 20 & 25 (and double up with the barlow)

I will then replace each cheap piece in time.

Hoping for clear skies over the bank holiday weekend.

[Norfolk star gazer]

The 9mm x-cel was delivered today and partially clear skies, so might get a chance to try it out.

One thing that I'm confused about is that it says that it's got a twist up eyecup, but when I tried to twist it up, it came off.

Looks like, it was held down by a little bit of glue and I can't see how it would have twisted up like normal eye cups?

Any ideas. I can see a trip to the shop coming this Saturday!

[Space Beagle]

One of the X-Cel LX eyepieces I used to own did this, I just re-glued it on with a very small amount of super glue and all was fine!

I think there are some old threads on the forum about this happening to some other SGL members too.

It's just the rubber piece of the twist up part of the eyepiece that comes loose, it doesn't affect the performance at all it's just a bit annoying!

Still very good eyepieces!

Doc