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Eyepiece selection query for beginner telescopes


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Hi All,
I've just joined the forum...

Back in the spring I bought my first scope, a Celestron Powerseeker 127. I realise this is an entry level scope but obviously I still want to get as much as I can from it before upgrading in a year or two. After reading many posts on sites such as these I realise I need to replace the cheap eyepieces that came with the scope. I've been reading good reviews of the Revelation eyepiece & filter kit, with 5 EP's ranging from 9mm to 32mm. This seems to be a good option considering I don't have the budget to spend £50+ on single EP's...

However I gather for planetary views you need a good EP in the 4-6mm range so I would be happy to spend extra on a stand-alone EP of this type. However can I really expect any decent planetary views with any EP, considering the scope I have? With the cheap EP's I already have I got good views of the Moon, but Jupiter only appeared as a small, bright white disc - with 3 moons showing up as faint stars. Would this improve with a quality 4-6mm EP or am I expecting too much?


Any expert guidance would be much appreciated!
Kind regards,
Mark

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Mark

Welcome. I bought a set of EPs when I started and they were ok to get a feel for things. Would i do it again, no. You won't need many EPs and a 4mm would be too much for that scope I'm guessing at a magnificiation of 250. You will see good detail on Jupiter at about 140 mag and upwards, but the image will be small. I'd say the highest you should go is about x175 with your scope but maybe a little higher on nights where the sky is very very clear and steady. I owned a few Starguider/BSTs and at £50 each they will do you for a long time or until you start really investing in the hobby. Get the 25mm, the 18 and the 12 and maybe a barlow.

Good luck

Barry

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you will get better views with better eyepieces but how much is debatable the problem with eyepiece sets is they are not great value for money in the sense that they are not the eyepieces that you would necessarily choose for your scope so some would not get used that much . there is no doubt that buying as a bundle saves you money but for me I would rather have 2 good eyepieces I use rather than a set of several not so good ones With some I never use or use rarely. I would get a couple of bst starguiders for a similar price in a focal length I use often. (but thats my opinion)

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Hi Mark/Markstar and welcome to SGL.

As per the earlier relplies from Bart rowan46, I too would advise that you purchase individual eyepiece than going for a set. Many SGL members recommend the BST's from Alan at 'Skys the Limit'. I have purchased a few items from him and I have been more than pleased with his service. He is an ebay seller. You can always phone him for advice.

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Ignoring eyepieces specifically, you will get a good view of Jupiter with 80x, you will get a good view of Saturn with 120x.

So it comes to what eyepieces on your scope are needed to get either, or both.

If the scope is 1000mm FL then an 8mm will give a decent view of both Saturn and Jupiter.

One proviso is that for Saurn and Jupiter and planets in general you want a fairly sharp/crisp image. If Jupiters bands or Saturns rings are not well defined I find the result is not as good.

So possibly be willing to drop to 100x for Saturn.

If you get a good image at greater then 120x then great, go for it, just magnificatiuon is not the answer to everything.

Also remember they are not handing out premium eyepieces in the revelation set.

Suggest you look at an 8mm eyepiece for your scope, a 4mm is pointless.

Sky's the Limit do a 7.5mm plossl, would give 133x. (£24) - little eye relief so if you wear glasses forget it.

I think your scope has a built in barlow/magnifier, so not sure how good an image it will manage with the previous. Also don't think placing another barlow in the path makes sense either, not sure of the design that is built in and that is a factor.

Do you know anyone to borrow something similar from (8mm plossl). Makes choosing/deciding a lot easier.

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Markstar.......... invest in an 10 -18 mm lens in the knowledge that it can be used later on in life. Any Plossl type lens is a standard lens, but eye relief is smaller at lower focal lengths. Dont waste your money on a full set now, as it wont bring any alarming rewards for your present telescope.

I agree with Bart, the Starguiders are good ( my 8mm is good for me - everyone is different though, lenses are individual, but the BST has good eye relief and 60 degree view?) and rowan says "better views with better eyepieces", but a better telescope sooner than later will reward you better.

Now this may hurt? I started with the Powerseeker 127EQ, purchased second hand in October.......lasted about two weeks max. Then upgraded to the  Skyliner 200P. The 4mm & 10mm Celestron EPs would make great bases for candles i`m afraid.  I`m sure it even says in the manual, that you have to return to the manufacture for collimation? I removed the M1 (primary mirror) and added a blackened hole re-enforcement sticker to help with manual collimation using the standard 35mm film cap/eyecap with 1mm hole. The scope is setup to the best I can get it, but Jupiter is still just a small spot of light. You cant use a laser to collimate, because of the corrector lens at the base  of the focuser assembly. The Moon is good to look at, as Ive only used lower powered binoculars in the past. Then there`s the setup, align with North, Pitch up to sight with Polaris, adjust the poor finderscope, then mess with the mount screws everytime you need to look at another object. I would not advise you to buy a full lens set outright at this stage, for that telescope. I think you will be saddened by the results, as they wont improve what you have enormously, and you`ll end up with lenses that probably wont get used.

I know their selling this scope for about £199.99 in a still surviving high street chain store in uk, but I now see that as a very basic starter scope, for looking at the Moon only. Mine is a give-away for about 50-ish notes(collect only, but I will explain the limitations,to any purchaser, but an adult buying a cheapy telescope for their child at Christmas wont really hurt their budget - they probably wont even notice the modifications that it will receive, such as a better lens, and possibly flocked! (as a practice for my self) should I want to try that on the Skyliner) but only as a starter scope for lunar observations? The slow motion tracking wheels are ok, but thats about it for me.

Its all down to the Telescope producing an acceptable image at the focal point. All lenses including those supplied will allow you to see and magnify that image. Some lenses are far better. But the whole optical train has to work as one. My Celestrons 4mm lens was removed (dissmantled) for cleaning ( I would`nt advise it, its hard to find when you drop it? but i`m sure its made of plastic- I tried everything to improve the images, but to no avail, and they even supply  you with a 3x Barlow - crazy!)

 

ronin is guiding you in the right direction, however I would suggest for the Powerseeker, a magnification of between 32x - 62x power would be about the optimum (  32 - 62x power would be lenses between 16mm and 31mm. I would buy the 18mm for now if you only choose one, and can be be Barlowed for higher magnification. All food for thought!

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Hi Mark, I started out with the same scope as yourself and got a few upgrades to make it a little better. The finderscope was dire so that was first to go, then I replaced the barlow. Just before I got my 200p I bought a zoom eyepiece of ebay for it, they come under various names from different sellers but branded "Starguider" here http://www.ebay.co.uk/itm/Starguider-7-21mm-1-25-Zoom-Telescope-Eyepiece-Lowest-Price-in-the-World-/380482031362?pt=LH_DefaultDomain_3&hash=item58967f0f02 for the money its actually pretty decent, I still have mine and use it with my PST. It is definitely an eyepiece I would recommend to accompany the 127eq instead of spending more on a kit with a bunch of stuff you probably will not use.

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Thanks for all your advise, guys! I'll certainly take your comments on board. I'm going to try to find some images of what you can hope to see with my scope under good conditions, with the eyepieces you suggested.

Which conveniently brings me onto another query - astrophotography! This is also something I'm interested in. Again though, is this something I should forget about until I have a better scope...?

Many Thanks,

Mark

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+1 on getting BSTs they should last for you a long time. In the unlikely event that you want to sell them then they get a fair price - they rarely come up in the classifieds.

I can only echo that magnification is not everything eg at the weekend I got some fantastically sharp views of Jupiter at 100x but at 188x everything started to get very soft and yet only a couple of weeks ago Jupiter was sharp at 188x. Viewing conditions vary so much.

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I use BST From Sky's the limit, (find him on fleebay) these are great lenses for the money  I have the 25mm,18mm, 12mm, 8mm, 5mm, & 2x telvue barlow lens.

At £49 squids each these are great lenses for the money and good value, I reckon you would have to spend £100 squids plus each to better these lenses :smiley: . 

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I would echo that the BSTs are good value as are the various versions of the 60 degree 'planetary eyepieces'. 

The latter are pretty good at the short focal lengths but I would avoid the longer focal lengths. I had the TS 25mm version and it suffered from terrible field curvature at F6.

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Which conveniently brings me onto another query - astrophotography! This is also something I'm interested in. Again though, is this something I should forget about until I have a better scope...?

Many Thanks,

Mark

The mount is more important in astrophotography than the scope. The minimum recommended mount to use (although if you throw away more subs you can get a lighter weight mount, but it's not recommended) is a HEQ-5 Pro Synscan / Syntrek - which are about £500 2nd hand (about £750-£800 new), then there is the DSLR, then the Laptop, then the scope (Skywatcher ED80 - about £450 new or £250-£300 used), then a Field Flattener and Reducer (£160 new). You are easily looking at £1,000 to get started with Astrophotography.

Before getting into it though, I'd recommend buying this book, it should answer some questions for you and save you a lot of money.

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Ok - I guess I' m thinking a bit too far ahead when it comes to astrophotography...ha ha!

Regarding EP's tho, I've decided to go for 3 BST Explorers at 8mm, 18mm and 32mm. If I'm happy with the results I'll then invest in a decent barlow too...glad my other hobbies are less expensive!

Just been out looking at the moon with my current crappy EP's...hoping to see more than the moon soon tho!

Thanks for all your input...if anyone is horrified by my choice of EP's feel free to let me know!

Kind regards

mark

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I must be the only person who likes the Revelation plossls.

I understand the need to buy quality gear

These are the only eyepieces that Revelation sell.

So to say that they don't put the best items in the kit is a bit misleading.

There is no other alternative - yopu get what you are given.

They are 52 degrees FoV and they work. What more do I need from them?

£22 Revelations

£50 BST's

£100 Baader Hyperions

£250 Televue Delos

£500 Televue Ethos

I have been using the 12mm and 9mm Revelations tonight - no problems.

The moon and Jupiter came up OK considering the weather and the drifting cloud cover.

These two plossls have served me well on the 3" reflector,

and are working OK with a 2x barlow on the 8" dob for higher magnifications (reaching the parts that the MaxVision 16mm can not reach)

Out of the Skywatcher / Maxvision / and Revelation eyepieces I own, only the Revelations have retained the internal black coating on the filter threads.

I was really dissappointed when the soft paint wore off the inside of the MaxVisions leaving a shiny stainless steel surface.

The Revelations still look brand new.

And the observing I am getting at the moment can't justify spending >£100 each on replacements.

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Why not purchase just one EP first instead of splashing out on three? This will let you get a feel for whether you get on with it or not.

The BSTs are a good first upgrade, but as always I'd recommend getting used to what you have first before parting with any cash.

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Why not purchase just one EP first instead of splashing out on three? This will let you get a feel for whether you get on with it or not.

The BSTs are a good first upgrade, but as always I'd recommend getting used to what you have first before parting with any cash.

Same, I bought one to start with, a few more followed though. I'd agree the 25mm BST is the weakest but also the one I've used most, so that may have bearing on it. Suffice it to say, very briefly since I am a bit too tired to write after a long session under the stars and about to go out again, aberrations are noted in it. Still a very nice eyepiece though but there are alternatives at that price for a 25mm that may be a better option.

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Yeah, perhaps I should just get one of the BST EP's to start with...and 'Wookie1965' - thanks for the correction re no 32mm...my thinking is the BST's will last for when I upgrade to a better scope.

I also have a query re Barlows - considering the scope I have (Celestron PS 127eq) should I get a quality 2x barlow or a 2.5x televue powermate - which works best with the BST EP's? The powermate apparently eliminates the issues that barlows have...but would the difference be noticable in the scope I have...?

I assume either will be be superior to the plastic-toy 3xbarlow that came with the scope...?!

Thanks, as always!

Mark

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BTW the focal length of my scope is 1000mm, so I gather this means the focal ratio is just under f8...I get the impression the focal ratio also plays a factor in choosing EP's and Barlows...?

Ta...Mark

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BTW the focal length of my scope is 1000mm, so I gather this means the focal ratio is just under f8...I get the impression the focal ratio also plays a factor in choosing EP's and Barlows...?

Ta...Mark

Hi Mark, only in the sense that fast scopes, ie. f/5 and faster are not so good with cheaper ep's because of the steeper light-cone.  However, your scope at f/8 will work well with most ep's.  The f/legnth of your scope is the only thing you need to use when considering ep's as this is used to calculate the magnification, ie. focal length of scope divided by focal length of ep = magnification.

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Hi Robin...many thanks. I think I'll be cautious and just go for one new EP to start with. I'll go for a 8mm BST Explorer...partly because I went scouting for viewing locations a few nights ago and found a great spot for viewing Venus after sunset. If I like the results with this EP I'll invest in a couple of lower mag Explorers for star clusters and the like...maybe a powermate too...it is my birthday soon, after all! There seems to be a recurring theme of quality, not quantity, when it comes to choosing EP's...

Regards,

Mark

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You will get some great views of all the planets with the 8mm as far as the Barlow is concerned you will be pushing the magnification with the 8 or 5 if you decide to buy that but the others would be ok although wont be much use i.e 25mm Barlowed 12.5 you can buy the 12mm, 18mm Barlowed 9 you are already getting the 8mm same with 15mm and the 12 for the 5 do you understand, would be  a waste of money.

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