eyepiese for f5 scope

[kipstar]

sorry for starting a new topic should i get a 6mm vixen NPL or a 8mm one will my scope handle the 6mm i want to use it with a x2 balow lens thanks for your help

[Qualia]

sorry for starting a new topic

No, Kipstar, I feel you have no need to apologise. You just continue asking unti you're sure. And you know? It's lovely to chat astro and it's great to be able to offer advice, so the way I see it, you're doing us a favour

Anyway, to be able to answer more coherently, what do you fancy viewing with the given EP and what is the aperture of your telescope?

[kipstar]

thank you yer it a skywatcher d=150 f=750 i have a x2 barlow lens as well i have a super 10mm and a super wide field view eyepiese as well planets mainly and to try see as much of the messier catalog as i can i am saveing up at the moment to upgread my scope but thats an ongoing project so just wanted to get a good eyepiese to get some good views with for the meen time i know theres only so much my scope can do i have got a 6mm seben eyepiese but to be kind its not good at all very blurry image but its a very low cost eyepiese thats why i asked about the 6mm vixen NPL or the 8mm becouse how bad the seben eyepiese is or can i just put this down to how low costeding the seben is and the 6mm vixen NPL will be much better thanks for your help mate

[kipstar]

its a super 25mm wide field view eyepiese missed that bit out haha

[Naemeth]

In my view, there are two approaches to take:

1) Excellent Quality (but not ridiculous expense) right off the bat

2) Good Quality (less expense but may need upgrading at some point)

In category 1) I would recommend TeleVue plossls as these have a great reputation and are tested down to F/4. I recently acquired an 8mm, but have not had the chance to use it yet due to cloud. The eye relief (distance your eye needs to be from the eye lens to get the full field of view in) is short though, as is the eye relief on short focal length plössls. Having said that, an 8mm TV plossl would work well for your scope, giving 93.75x which should see a lot of use as both an eyepiece for planets and one for closer views of some DSOs. On the other end, I would recommend a 15mm or a 20mm and use that as your main DSO eyepiece. This would probably cost about £120 if you got them second hand.

Category 2) Vixen NPL 8mm (although beware the short eye relief), Vixen 30mm NPL / 20mm NPL, at about £70 new.

I wouldn't use a barlow, personally, on a 6mm eyepiece. Partly because I do not like barlows, and partly because it gives 250x on your scope, which would be more susceptible to the atmosphere and would produce a less-than-clear view. Still pleasing, but you certainly lose detail to the atmosphere the more you magnify.

[cotterless45]

I'd go with Bst Explorers (Starguider),these are very relaxing to use and give sharp views across the range. Given the few super seeing /transparent nights we get , I wouldn't be spending shed loads on anything much.

Most Messiers can be seen at lower magnifications, a 25mm will give you x30 for searching and a x12mm will give you x62 for a closer view of galaxies. I don't like fiddling around with Barlows.

More magnification requires accompanying seeing conditions, the excellent 8mm is the lowest I'd go to in your scope, giving you x94 to view deep sky objects,

Nick.

[Mattscar]

+1 for the BST's, couldnt be happier with mine and the eye relief is so much nicer compared to the standard EP's.

[ronl]

I agree with Nick, the BST Explorers are really good and great value for

money, I also have the cheaper BST Planetary wide angle, very good

especially for the moon.

Clear Sky's

[Merlin66]

I can only say I bought my TV Plossls almost thirty years ago when I was seriously using a 12.5" f5 - they worked very well.

Since then I've changed scopes (many times!!!) and the ol' TV's are still with me. As good as they ever were (I only wish I could say the same about my eyes)

A lifetime investment.

[damnut]

Another vote for the BST Explorers. For me they offer one of the best quality v price eyepiece range.

[faulksy]

I would recommend the ts-hrs from modern astronomy, the bsts are good but they have a slight yellow tint the ts don't. sorry to be different guuys some one has to. the price £46

[Qualia]

I can only say I bought my TV Plossls almost thirty years ago...I've changed scopes (many times!!!) and the ol' TV's are still with me. As good as they ever were...A lifetime investment.

Merlin has succinctly said rather a lot here and it would be interesting to see if ten, twenty, thirty years down the line the same could be said of BSTs, X-Cel LXs, Hyperions, Vixens et al. After owning various types of the former three EPs, I have a sneaky feeling that this just ain't going to happen.

Anyway, not looking at brands, and exit pupil for now, I feel you want to be aiming for these ranges of magnification:

• 40x - 60x - widerfield, handy for star hopping, nice for star fields, given nebulae and galaxies and large open clusters, perfect for white light solar work.
  
• 60x - 90x - as above, but just getting in there a little more.
  
• 90x - 170x - sweet spots kicking in for globulars, galaxies, Jupiter, Saturn, Venus, Mercury, nebulae, lunar work, measuring sunspots and small lunar craters etc
  
• 150x - 250x - nice mag for good night's seeing esp for Saturn, Lunar work, some globulars (lower end of the mag), spliting easier doubles and taking their measurements etc.
  

With just a set of 3 TVPs and a barlow, for example, and one has pretty much covered a lot of ground: 25mm & 12.5mm / 15mm & 7.5 / 11mm & 5.5mm.

[umadog]

Or the same as Qualia's post but framed in terms of exit pupil and power per inch: http://www.cloudynights.com/item.php?item_id=547

That makes the guide aperture-agnostic since on a large scope your lowest power may be 100x and on a small scope you might struggle to get 150x. With seeing being what it is where we live, nobody is getting past 250x except on the best nights. 350x would be a superb night.

[Moonshane]

although the advice above is goo, and I agree with it, I'd come from a very different angle. for me there's little doubt that a better / larger scope will have far more impact than any eyepiece, even the best money can buy. I am not sure if you are any good at DIY but it's very simple to create a dobsonian base to a half decent standard and you could then buy a 8" or 10" scope to put on it. personally, I'd be saving my money to buy a larger scope rather than buying more eyepieces.

although that said a skywatcher 6" f5 newtonian is a very good quality scope. perhaps your issue with the eyepieces is related to cooling or collimation? please note that you need to leave the scope outside for at least half an hour to an hour before the views will stabilise. also your collimation at f5 needs to be pretty close or the views will be mushy. perhaps it's a combination of the two?

I have read that the Seben eyepieces (not the scopes which I understand are poor) are quite good for their value.

hope the above helps. before you start spending, check your collimation if you can (or find someone local to you that can help), let the scope cool, and spend some time with the eyepieces you have. you might find it's actually a lot better than you initially think.

[AlexB67]

although the advice above is goo, and I agree with it, I'd come from a very different angle. for me there's little doubt that a better / larger scope will have far more impact than any eyepiece, even the best money can buy. I am not sure if you are any good at DIY but it's very simple to create a dobsonian base to a half decent standard and you could then buy a 8" or 10" scope to put on it. personally, I'd be saving my money to buy a larger scope rather than buying more eyepieces.

although that said a skywatcher 6" f5 newtonian is a very good quality scope. perhaps your issue with the eyepieces is related to cooling or collimation? please note that you need to leave the scope outside for at least half an hour to an hour before the views will stabilise. also your collimation at f5 needs to be pretty close or the views will be mushy. perhaps it's a combination of the two?

I have read that the Seben eyepieces (not the scopes which I understand are poor) are quite good for their value.

hope the above helps. before you start spending, check your collimation if you can (or find someone local to you that can help), let the scope cool, and spend some time with the eyepieces you have. you might find it's actually a lot better than you initially think.

That is the approach I'll take I think, I recently bought a fairly cheapish UWA skywatcher 6mm, to replace my 10mm stock with barlow combo to give a near enough similar magnification. I did not want to spend too much on the higher power as I probably would not see myself using it that often, but while the moon was out and saturn is still in a reasonable spot from my back garden I bought it and don't regret it at all for planetary use, it fitted right in my budget, and I definitely like it more compared to the stock 10mm with 2x barlow combo, it works well for me.

I am looking to buy the BST exploreres for the mid range magnification, perhaps a 18mm or so and perhaps one more for the magnifications I imagine myself using the most. Once I have that in my collection I'll probably not buy and spend loads on eyepieces after that, but instead exhaust my current scope and eyepieces as much as possible, get to dark skies with it, already got a trip planned soon but more of that later in the year in the autumn to see what I really can get out of my current combo. It does not have to be a money sucking hobby I feel to get much pleasure from it.

The cost of eyepieces can get very high indeed when I look around, and I'd rather put my cash aside for the future once I have my essential reasonably priced eyepieces and then buy an 8 or a 10 inch dob in future, but I am in no rush until i feel I've got the most out of what I've got. I don't even see myself ever selling my beloved Heritage 130p, perhaps because it is my first scope and it is of sentimental value . The Heritage 130p is such an easy grab an go, I am out and observing in minutes, without setup and carrying around hassles. Had I gone for a big scope like a 10 inch from the beginning I'd probably would have had only a half the number of sessions with it considering the weight, cooling down time, regular collimation needed etc. etc.

So the moral of the story for me perhaps more scopes, less eyepieces. who knows may I change my mind in future

[Moonshane]

the moral of the story is more scopes (and!) more eyepieces

seriously though, although I personally buy good quality at a cost, the difference between more aperture will always be greater than better eyepieces at least to a point and assuming quality as good as Skywatcher for example. if I could only have one option:

1) 12" scope with average quality plossls

2) 6" scope with Televue plossls

I'd go for option 1 any day of the week.

[AlexB67]

Not that I ever looked through a 12 inch but I like where you are going, that is what my gut tells me and from learning and reading around. If you asked me for a swap of 1 versus 2 where the total cost would be similarish, I'd go 1 in a heartbeat

[Qualia]

...for me there's little doubt that a better / larger scope will have far more impact than any eyepiece, even the best money can buy.

Ay, I like that a lot, Shane and fear I'm going to pinch this advice when responding in the future Makes a lot of good sense and thank you for sharing this.

the moral of the story for me perhaps more scopes, less eyepieces. who knows may I change my mind in future

It's an interesting proposition, Alex, perhaps not for everyone but it makes a lot of sense. In my case, although it didn't really happen consciously, over the last four months there has been a gradual drift towards cutting down on EPs which coincided with the purchase of a gorgeous 10" f/5 dob and retaining the 4" f/10 frac. Apart from planetary and Lunar work which does require quite a run of EPs, the other x% of my viewing is done with just 3 EPs, and although over the next year or so, I will slowly upgrade on them (they're TVPs & a Tal EP) I can't see any necessity of wanting to get different focal lengths. As it stands, I really can't up the weight on the 10" and retain excellent portability and don't see any point losing the 4" frac which is a joy to use when looking at the sun in white light. I figure for now the price of 2 premium-premium EPs that I require to perfect my case is also the price of a basic H-Alpha telescope, so guess which way I'm going

[kipstar]

are these anygood

1.25" 8mm 58 Degree TMB Planetary II eyepiece

[Naemeth]

are these anygood

1.25" 8mm 58 Degree TMB Planetary II eyepiece

As a starting eyepiece, they certainly are a step up from the supplied eyepieces. However, they suffer from both internal reflections and ghosting, particularly evident on Jupiter. I think BSTs are better, and TV plossls are a step up from that. Considering the price difference between a new BST (£47) and a 2nd hand TeleVue plossl (~£50 - £55 on shorted focal lengths, £70 ish on longer focal lengths), I think you get a lot for an extra £3 - £8 and £23 respectively.

[kipstar]

thanks mate so best to put the rest in and get a bst or Vixen npl and if i can a tv plossl moneys a big problem as it is for everyone thanks for your help

[kipstar]

ever used one of these

Starguider 7-21mm 1.25" Zoom

[Qualia]

Looks like the one Skywatcher make, sold in Europe under a few different names such as Omegon.

I would save your money for now and just work with the supplied EPs. There are some decent zooms about - the Hyperion springs to mind - but as you'll appreciate they're quite a lot more money and even then probably don't perform quite as well as fixed focus eyepieces.

I agree that this type of zoom would be a very cheap way of boosting your EP collection but I feel you're going to be a tad disappointed further down the line. In my experience, in this esoteric hobby of ours, you pretty much get what you pay for. Personally, I'm rather swayed by Naemath's argument above or else giving FLO a ding and enquirying about aSkyWatcher Plossl or two.

[AlexB67]

the moral of the story is more scopes (and!) more eyepieces

seriously though,

Indeed, seriously, coming to think of it, you are right I was thinking about the order of things, more eyepieces after more scopes in the long run