Barlow or new eyepiece?

[BilliGoatsGruff]

So I've come up with another question (they seem to be endless!) What do people recommend; getting a Barlow or investing in new eyepieces? I already have a 25mm and a 10mm eyepiece, but I honestly have no idea where to go from there. I'm hoping for something to get better planetary views that my 130p can handle.
thanks in advance :D

[OzStarGazer]

Hi again. :)

I had written this in the other thread:

I will add here that it also depends on what you want to do. For astrophotography (afocal mode) an eyepiece is definitely better, but if you just want to "see" more details a Barlow will do at the beginning of the journey. Even cheap Barlows magnify, although the quality of the images could be better. BUT of course not only details are magnified, but also possible turbulences...

[BilliGoatsGruff]

I do remember reading that :) I'm not interested in astrophotography, just viewing is enough for me. It would be nice to have something that can give me better views of the planets. Probably the max I would go with a barlow is 2x to keep as much image quality as possible. Would the scope be able to handle a 2x barlow with a 10mm eyepiece, do you think?

[OzStarGazer]

Only when the weather conditions are good... I did use a 2x Barlow a couple of times with the 10mm EP, particularly in my early days (which were just over a year ago... :)). I now have a 6mm EP, so I usually use it on good days. But the Barlow should be OK too on good days (well, nights). :)

I find this resource very useful by the way:
http://www.stargazing.net/naa/scopemath.htm

You can enter the specs of your scope and it gives you all values as well as recommendations towards the end of the page. It says that the "optimum" magnification for our scope is 33 to 65, corresponding to 20 to 10mm eyepieces, but this would be the optimum magnification on any day. On very good days you can go a bit higher. :) (With the Barlow and the 10mm eyepiece the magnification would be 130. The 260 maximum magnification SW mentions only happens when the weather conditions are ideal, which only happens once or twice a year they say, so it is better to forget about it.) :(

[OzStarGazer]

This is the one I bought by the way:
http://www.ebay.com.au/itm/Brand-New-Celestron-2x-Barlow-Lens-1-25-Fully-Multi-Coated-/121599716210?pt=LH_DefaultDomain_15&hash=item1c4fe86b72
It was 10 dollars cheaper 16 months ago! You can probably find something cheaper now if you are on a tight budget. It is not a professional one of course, but it is OK for beginners.

[OneSmallStep]

Thanks for sharing, that's an excellent resource to get an idea of how it all works and the limitations.

[ausastronomer]

Hi Billi,

What telescope do you own and are your 10mm and 25mm eyepieces you have the generic plossls that came with the scope?

Cheers
John B

[BilliGoatsGruff]

Hi John :) I have the SkyWatcher Heritage 130p. It's definitely a great beginners scope! The 10mm and 25mm eps were included with it.

[BilliGoatsGruff]

Sooo... would a 6mm ep be better than the barlow, in your opinion? I know it's all down to personal opinion, but I can only get one so I'm being careful :D

[OzStarGazer]

Well, I like to take pics of the moon :), and I find it easier with just 1 EP (when I am taking pics in afocal mode, which means with just the camera in front of the EP). The image quality is also better because my 6mm EP is for planetary viewing.
If you buy a Barlow you could also use it with the 25mm EP of course, which would then be like 12.5mm, as well as with future EPs.
Maybe others can tell you what they think too... I first bought the Barlow and then the 6mm EP, but not because I was totally unhappy with the Barlow. I am obsessed with the moon :) and wanted to get as close to it as possible in the best possible way and take pics of it, as I said, but the Barlow was OK too. Well, at least not bad for quick magnification. I just felt I needed more.

[OzStarGazer]

There is an old thread about your scope and a Barlow:
http://www.iceinspace.com.au/forum/showthread.php?t=130340&highlight=barlow

[BilliGoatsGruff]

This was definitely interesting!

[BilliGoatsGruff]

Bintel has one for the same price:
http://www.bintel.com.au/Eyepieces-and-Barlows/Barlow-lenses/Bintel-Barlow-br--2x--1-25--/890/productview.aspx
of course there's the cost of postage with that one, so it bumps the price up.

I guess the real question is; does a Barlow affect image quality? Perhaps I should have asked that first.

[brian nordstrom]

:thumbsup:I have only used my Celestron Ultima 2x 1 1/4 inch Barlow that I have had for many years and find it one of the best, sadly not made anymore but the TelVue 2x is of equivalent quality, at a price of course , and still available.
On the quality question all the cheap 2 and3x Barlow,s I have ever looked thru did not by a long shot equal an eyepiece that gives the same magnification , its like a vail over the view where as the good quality ( expense. ) Barlow,s don't.
On that when I want higher powers using my 2inch eyepiece, my TV 2 inch Powermate is the best. , tho really expensive. .

So my opinion is if you cant afford a TelVue or equivalent don't bother as you will be disappointed in the long run. , grab a nice TMB 6mm , this will be better.

My. 5c.

Brian.

[BilliGoatsGruff]

Thanks Brian. I did consider getting a 6mm of some sort. What's the eye relief like on them though?

[OzStarGazer]

Billi, if you are interested that's the one I have too. I bought it on AliExpress, where they are pretty cheap. They are clones, but basically they are all clones these days because the original manufacturer doesn't make them any more if I remember correctly? It arrived pretty quick from China, in about a week or just over a week.
PS: The description says that the eye relief is 16mm.

[BilliGoatsGruff]

The 6mm from Aliexpress works out to be roughly $45. I wish our dollar was worth more than America, then we could all get awesome stuff for dirt cheap :nerd:

[OzStarGazer]

There was a time when our dollar was indeed a bit more than the USD (not much, but still better than 1:1). Beautiful times! I should have bought more back then. :P

[ausastronomer]

Hi Billi,

I am going to come at this from a different angle to where everyone else pointed you (Brian did at least suggest not to waste your money on a poor quality barlow). The scope you have is a very good entry level scope and should last at least 1 year and possibly 2 or 3 years. These have a parabolic primary mirror and assuming fault free optics should be capable of running to a bit over 200X on the moon and planets, which you would achieve with a 3mm eyepiece. Seeing conditions on a large number of nights might prevent you going this high.

What I have learned over many years is that people often upsize, downsize or change telescopes but they will generally keep good quality eyepieces for a very long time and use the same eyepieces, in different scopes, as they change scopes. Consequently, I think you should head away from the budget end of the market as those eyepieces and barlows will only ever be that. At some time in the not too distant future, as your observing skills improve, you will realise that the eyepieces that came with the scope are pretty ordinary and you will look to upgrade them. Buying more cheap eyepieces and accessories IMO is only burning money as you will at some time in the future give them to someone because no one will buy them when you want to upgrade. I think you should start to assemble some better quality eyepieces now, which you will keep for many years. If you don''t keep them for years you can at least sell them and get your money back on them. Whilst not everyone can afford to go and buy a new set of Pentax XW's, Ethoses or Deloses, there are some excellent high quality eyepieces which can be bought very reasonably on the second hand market. I think this is where you should start looking. Be patient, they may not come up this week or next week, but they do come up and you can start to build a good set of high quality eyepieces over a period of time. Most importantly you will be able to sell these for about what you paid for them.

I think you need to get something in the 5mm to 8mm range as your next eyepiece to give you a bit more power on Solar System targets. I would look for something like a 2nd hand 5mm, 6mm or 8mm Televue Radian, or a 5mm or 8mm Vixen LVW, or a Pentax XF 8.5mm. You can often buy these for somewhere between $130 and $200. If you upgrade your scope in the future; and as your observing skills improve, you will realise that these eyepieces at least allow the scope to deliver its best performance and it is not handicapped by mediocre quality eyepieces.

Whilst $150 to $200 may sound like too much money at the moment, you would always be able to get most of your money back in the future if you ever want to sell them. if you keep buying $50 eyepieces you will have an eyepiece collection worth $0 because they are basically not saleable on the second hand market.

Cheers,
John B

[OzStarGazer]

She said that she cannot buy a cheap Barlow AND a cheap eyepiece (which together would be less than $100), so I assume $150 to 200 would be too much for her. But I don't think it is a real problem at the moment.
Of course it is a journey and she will want more one day, but she seemed to be pretty happy even with the cheap eps and what she was seeing so far, which is good as that's all that really counts - to feel happy and enjoy what one is seeing. I feel a lot of *admiration* for her and her enthusiasm. :thumbsup:
She also has kids, so when she wants to upgrade she can give them her old scope and eps.
Maybe AstralTraveller was right in the other thread she started and she should wait to buy any new eps altogether for the time being. After all she just got into astronomy.
I personally am waiting for a better location to upgrade. At the moment I cannot move due to health reasons as the moving agency doesn't do everything and I cannot do it myself at the moment.

[OzStarGazer]

By the way, Billi, this is what an established eBay seller (Skies Unlimited in the UK) told me last year about eyepieces for our scope in the early days (I had had my SW for about 6 weeks back then):

Series 500 are a very good general purpose Plossl and are perfectly fine for many astronomers in the early years of learning about the subject. The ones that we sell as 50 degree Plossls are the next ones up the scale as they let you see more of the surroundings of a target which helps make them easier to find as well as putting them into context of the surroundings. They give the same magnification per mm of focal length as the Series 500 but say you were looking at a crater on the moon then you would see more around it - hence the context benefit.

If you are feeling brave you might consider the next rung up the ladder of eyepieces and look at the TMB Planetary 2s or the BST Starguider EDs as they will give you more benefits in terms of contrast, brightness, sharpness and field of view. Our 8mm is the most popular eyepiece that we sell and you can Barlow it to 4mm when conditions allow - but once you have tried it in a Barlow you will be very tempted to buy the 5mm one!

Alan is a very honest person (as you can see he didn't even try to sell the most expensive eps and sounded encouraging throughout) and I bought quite a few items from him (including the Starguider).

[brian nordstrom]

:thumbsup: Very , very good advice John , it just takes years to collect a good set of eyepieces , if you don't win lotto :P..
Over many years I have owned and used many different eyepieces and now almost exclusively use my full set of Radians ( all got 2nd hand over years ;) off the IIS classifieds ) , 19 , 22 , 24 and 27mm Panoptics , along with the before mentioned 2x Ultima and 2x PM is all I ever need , love this gear , it's great in all my scopes for all types of observing .

Brian.

[OzStarGazer]

I have just bought a Radian myself. Why not? Oh well, it is always cloudy, but I can use it later. If I like it I will buy more.

[BilliGoatsGruff]

You've definitely raised some good points. I'm not overly worried about reselling in the future because I can keep the cheaper eyepieces for my girls. I figure if I get a cheaper 6mm now then I can upgrade to a better quality one when I can afford it :) at least that way I'll know if I like what I'm using.
I'm only a baby when it comes to astronomy so that means taking baby steps. I'd feel awful if I spent $100 on an eyepiece that I won't use.

[BilliGoatsGruff]

This is also true. Maybe I'm just being greedy and impatient?

[brian nordstrom]

:thumbsup: You will be impressed !!! good onya . this is where my TV fetish started , an 8mm Radian got from here ,, enjoy .

Brian.

[dannat]

i have seen the 10mm which comes with those scopes & it isnt great [the 25 is very usbale], a GSO plossl will be much beter, below 15mm in plossl config the viewing becomes uncomfortable as the eye relief is tight & you need to get your eyeball very close to the eye lens.
for solar system targets you should be able to support a 5mm eyepiece, giving 130x magnification. for your scope the BST explorer eyepieces are good quality, they are not to televue standards - but are close to 90% of the edge views of something like a radian. they can be had from telescopes-astronomy (http://telescopes-astronomy.com.au/)
which conveniently for you is located in SA, they are around the $80 mark. if you want to check reviews google AT paradigm [in US they are badged diff.]

[BilliGoatsGruff]

Hi Daniel.

I had a look on that website, but it's really hard to navigate. Where did you find the cost for the BST eyepieces?
I find that the 10mm is a little bit difficult to focus with. I'm not sure if it's a standard thing, but one teeny tiny bump of the scope and it gets a little fuzzy.

[BilliGoatsGruff]

I was considering the 10mm Orion highlight mentioned in this post:

http://www.iceinspace.com.au/forum/showthread.php?t=134697

It would surely have to be a step up from the one I have?

Or there are these:

http://www.iceinspace.com.au/forum/showthread.php?t=133827

To be honest I'm not really sure what to look for.

[MortonH]

The website isn't great. Best to call them or email them. Matthew Lovell (the owner) is very good to deal with.

I bought a 12mm BST Explorer from them last year. It was $85 plus $10 postage. They have 8mm, 12mm, 15mm and 25mm.


Sold it earlier this year because I had other eyepieces in the same focal length. Here's my ad from the time:

http://www.iceinspace.com.au/forum/showthread.php?t=131548&highlight=12mm+bst

[BilliGoatsGruff]

It would be good if the website was more user friendly :confuse3: I like to be able to see what I'm buying. I found a 6mm Orion Expanse on Bintel for $95, plus $10 postage, so it's not much difference cost-wise from the BST. Of course, they are all a bit higher than I was hoping to spend, buuut my birthday isn't far away so maybe I could convince a family member to help me out :2thumbs:

[OzStarGazer]

It is normal to show some interest in upgrading, but you can certainly wait at least a couple of months. Maybe you can also try out different eps in an astronomy club, so you can see the difference with your own eyes.
If you are not sure yet what you want (considering there are many opinions) I wouldn't rush.
Also, keep an eye on second-hand eyepieces in the IIS classifieds, just in case there is a bargain. Be quick if you see a bargain. The sales here are not auctions, so it is mostly first come first served.
PS: Oh, I have just read that it is almost your birthday. Good opportunity for a family member to pay for you! :)

[Renato1]

The 130p is a 5.1" diameter telescope and has 650mm focal length and an f/5 focal ratio.

So 10mm eyepiece gives you 65X and a 2mm exit pupil, which is the ideal eyepiece for looking at faint Deep Sky objects, but too low a power for planets.

With a properly collimated telescope and good seeing conditions, I expect the telescope should be able to hold 250X on some nights of the year - which translates to a 2.6mm eyepiece (i.e. a 5mm eyepiece in a 2X barlow, or a 6.5mm eyepiece in a 2.5X Barlow, 8mm eyepiece in a 3X Barlow).

But for most nights, I'd expect around 200X would be better, which translates to a 3.25mm eyepiece (i.e. a 6.5mm eyepiece in a 2X Barlow, or an 8mm eyepiece in 2.5X Barlow or a 10mm eyepiece in a 3X Barlow).
If you go for the lower power option, remember that you can increase magnification by around 10% by keep the eyepiece further out of the Barlow, rather than pushing it all the way in.

I don't know how good your eyepieces are - often the ones that come with telescopes may be mediocre.

My suggestion is to just be patient, and wait for either a very good eyepiece or a good Barlow that meets the parameters above, to show up in the classifieds.
Regards,
Renato

[BilliGoatsGruff]

Fingers crossed out local group will be having a meet up on Saturday (weather permitting) so if they do I'll tag along to that :D It would be good to catch up with people who know what they're talking about haha.

Dad's getting me The Backyard Astronomer's Guide, so maybe my mum could get the eyepiece :lol:

Of course, all good things come in time :)

[BilliGoatsGruff]

Renato, I'm not looking for anything lower than a 6mm right now. I've got my eyes glued to the classifieds for anything that comes up in my price range :)

[OzStarGazer]

You can also keep an eye on the Cloudy Nights classifieds, but postage might be expensive if the seller is not in Australia...

[inertia8]

Regarding the Orion Expanse, check out the reviews, from what I've seen the BST Starguider ED referred above would be a cut above for the same sort of price.

As suggested, hold off as long as you can! This weekend, weather permitting, should see the moon as just a sliver and you'll be able to use the 25mm to just scan across the sky.

I'd also suggest a Planisphere if you don't have one already and a small torch with a good number of cellophane layers across the front.

With regards to the fuzziness when touching the scope, this is unfortunately one of the quirks to these small scopes, the smallest vibration from touching it the eyepiece, or the table upon which it is sat, will induce a shake/wobble to the image that is more noticeable as you switch to higher power/short focal length eyepieces, so it is important to be able to sit comfortable and learn to sit very still, often focusing on an object, then moving it just out of the edge of the field of view and patiently wait for it to cross the field without touching the scope. It is something that you learn very quick with each passing observation session.

[OzStarGazer]

I like the BST Starguider I have. It is great quality for a reasonable price. It doesn't have a rubber eyecup you can flip up though (I don't know if this is what it is called).

[OzStarGazer]

Yes, collapsible is great, but there are obviously also some disadvantages in terms of stability, for example when you change the ep. Also always make sure the ep is firm in the focusser and that you have turned/tightened the screws enough to make it firm.

[BilliGoatsGruff]

Does you 10mm ep get wobbly when you focus it? For me to see Jupiter clearly last night I had to turn to focus wheel almost all the way out. Which makes me realise that the focus wheel gets wobbly, not the ep. Did you ever have this problem?

[inertia8]

That's part of the cheapness of the focuser. Some put some plumber's tape on the threads to firm it up, however it needs to be replaced every so often.

[BilliGoatsGruff]

I like that idea :) it'll definitely help with the problem.

[OzStarGazer]

I often had to turn the wheel all the way out with my 1st SW (they gave me a new one because the first one had a problem with the secondary mirror). I haven't noticed the wheel problem with the new one, but I have really not used the 10mm ep much. I just checked it worked when the scope arrived.
The focusser is definitely not the best. Here is a solution somebody had found, even if it is only a temporary solution:
http://stargazerslounge.com/topic/94074-puttting-a-crayford-focuser-on-a-heritage-130p-is-it-do-able/

PS: Ah, I see we all posted together in the last few minutes! :)

[Renato1]

But, assuming the specs I looked up were correct and the focal length is 650mm, then a 6mm eyepiece only delivers 108X. It's better than nothing, but is still ultimately low power for the moon and planets.

Your situation is problematic though, because if you bought an inexpensive 4mm plossl, well the eyerelief is extremely shallow (I had to take off the rubber eyeguard to see the entire field of view) - still useable, but annoying. I do have the more expensive TMB eyepieces at 4mm and 2.5mm which I got off Ebay, and they are okay because they have longer eye relief without weighing a lot like other more expensive eyepieces.

Good luck with whatever you choose. You'll soon realise that happiness is a new eyepiece in the mail.
Cheers,
Renato

[OzStarGazer]

Unfortunately yes, you are right. I actually got pretty close to the moon, but planets look really tiny, even with the 6mm ep. AND the images are pretty dark because for clear images at high magnification you just need more aperture.
Even higher magnification without tracking can be even more problematic. I use the Neximage 5 with my refractor (also small) and while I can get very close to the moon and on good nights it looks fantastic, it disappears from the screen super quick, so even when the weather conditions are good or excellent with hardly any turbulences I just see a few big craters drifting across the screen for a few seconds and have to constantly recenter.
So unfortunately small scopes without tracking have limitations in terms of aperture, no tracking etc. and 6mm is probably the limit on most days.

[inertia8]

I concur. Seems similar to the reviews of the Orion starblast 4.5 which state it is best for rich field views.

So, good enough to have a decent look at the moon and planets to whet your appetite for a larger aperture scope but excels at cruising the sky and looking at planetary nebulae and clusters.

Even when I get my main scope, I'll be keeping this little one unless circumstances warrant otherwise

[BilliGoatsGruff]

I ended up going with the Meade eyepiece kit in the classifieds. The seller has allowed me to pay in installments :)