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Old 28-12-2016, 07:59 AM
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Can I get some eyepiece advise please!

Merry Christmas to all and peace for 2017
I am just asking kindly if I can get some eyepiece advice for a newby (I am doing research and making the effort to learn too but advice can save you a lot of money and wasted time).
I have a Skywatcher Dob 10" that I got cheap second hand and as my first telescope I like it! However the cheapo Plossl eyepieces are not great and I need some advice on getting a good starting range. I have a Nagler 13mm (type 6) on its way for which I got second hand and happy about. I am wondering what else is a good essential eyepiece? I want some really high detail viewing too, so I was eyeing off something like a 5mm Nagler (type 6). I live in Logan city, moderate light pollution but not terrible. I am 41 and have good eyesight but want to really get some good detail (I am describing this badly and perhaps I mean make the use out of my 10" dob's potential magnification). For example would love to get great detail on Saturn, Jupiter, nebula or DSO objects (more than just pinprick stars and that is it!....the 13mm was recommended as a good alrounder, but any thoughts from you all out there? My scope doesn't travel, it stays in my backyard, and we live on a hill (so good sky views).
Peace to all
Andrew H
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Old 28-12-2016, 08:09 AM
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So your scope is f/4, f/5 ?

To start with you really only need 3 good eyepieces - low medium and high power. On your scope that means one around 30mm, the 13mm you now have, and one around 4-6mm (high power).

Apart from Televue, ES eyepieces are good, as are Vixen SSW and SLV (one of these would do nicely for high power). Vixen LVW are also very good though they are big and heavy, like a hand grenade, but no longer mad. While these are pretty much secondhand only, a few shops still have the odd new one left.

Also don't underrate plossls, there are some excellent ones.

For high power views of small objects like panets a wide field is not necessary, while maximum contrast and no ghost images are highly desirable. In this respect eupepeiece types with the lowest number of air-glass surfaces are better - even with modern anti reflection coatings - and for this reason there are a few types that stand out:

Monocentric, particularly the TMB monos,
Zeiss Abbé Orthoscopics,
Plossls.

To this add some of the modern designs including the Vixen HD, SSW and SLV.
Naglers and radians have many more air-glass interfaces and the result is more scattered light and lower contrast.

Last edited by Wavytone; 28-12-2016 at 12:37 PM.
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Old 28-12-2016, 08:46 AM
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Hi Andrew.
Welcome to IceInSpace
Congratulations on a great scope purchase.

I agree with wavytone. Dont write off your supplied plossls.
However, for when you have more money than you need ...
For my 10" DOB I found my Televue Panoptic 27mm was best for most (large) DSO's.
For a cheaper alternative I found Vixen LVW's to be nearly as good for a lot less.

The 13 Nagler will be a good general eyepiece (very very good actually)

And as Wavy said 4 to 6mm for planetary detail. Here, plossls are a bit tight, so I have used TV Radians (but these are no longer sold new). Alternative, use a good barlow with you 13 Nagler might even be better.
Once you have studied Saturn and Jupiter, I don't think you will have much use for high magnification, so seems a bit of a waste to spend too much on this end of the range.

Too many choices.
See if you can find a local observing group and see what they are using, and test them in your scope.
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Old 28-12-2016, 10:17 AM
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barx1963 (Malcolm)
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Andrew
Welcome to IIS!
Etepiece selection is an area that is very fraught for beginners and often for experienced observers as well. are you able to give us more details of the plossl eyepieces you already have? Often these scopes come with 2, often a 25mm and a 10mm. From experience, the 25mm is usually OK and the 10mm is not so. Reasons being the small eye relief and the narrow exit pupil. You may have already found this.

You suggest you are wanting high detail views on planets and are looking for power (magnification if you like) to do this. remember that if you increase the apparent size of the object you are viewing you are also increasing the size of any atmospheric blurring, and unfortunately there is nothing much that can be done about that (except moving to somewhere with steadier skies!!). The result is that high power images tend to get mushier as you increase the power so you need patience, especially with planets which are very strongly affected by seeing, to grab those fleeting moments of good seeing.

Getting to deep space stuff, you will find that for many objects there is a "sweet spot" as regards the amount of power you need to get the best out of it. This occurs as increasing power has 2 effects. Firstly it enlarges the apparent image that you are viewing which spreads the light over a larger area. As the total light you are collecting is still the same, that makes objects dimmer. But increasing power also darkens the sky background, so improving the contrast allowing the object to stand out a bit better. Objects with low surface brightness can benefit from higher power as a result.

All the above is a very simple explanation of some of the issues that you may have to think about, and I haven't touched on eye relief, exit pupils etc!

My usual advice to beginners is have a bit of a play with the eyepieces you have to get a better idea of how they work, and be prepared to realise that low to medium powers are where most of the fun is had. When I had my 12" dob, I did almost all my observing with a 24mm Panoptic that gave 63x and a 13mm T6 Nagler (same as yours!) that gave 115x. I did about 90% with the 24 and most of the rest with the 13. Occasionally I would pull out a 7mm Nagler but only rarely (and usually put it straight back in the case).

Anyway, hope the above helps!!

Malcolm
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Old 28-12-2016, 10:17 AM
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Hi Andrew,

I'm also in the Logan area, on a hill (neighbours?), and in my experience a 5-6mm eyepiece is about the limit of magnification on a 10" dob you could use before the image quality starts to decline pretty rapidly. With this you should still see good detail on Jupiter and some banding on Saturn in good conditions. The lower power eyepieces will also give you good views of DSO's, although if you're anywhere near the logan motorway/pacific highway, investment in a decent OIII/NB filter will help a lot with nebulae.
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Old 29-12-2016, 10:16 AM
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Hi Andrew,

I'm also in the Logan area, on a hill (neighbours?), and in my experience a 5-6mm eyepiece is about the limit of magnification on a 10" dob you could use before the image quality starts to decline pretty rapidly. With this you should still see good detail on Jupiter and some banding on Saturn in good conditions. The lower power eyepieces will also give you good views of DSO's, although if you're anywhere near the logan motorway/pacific highway, investment in a decent OIII/NB filter will help a lot with nebulae.
Hi Patrick
I live in Cornubia and it is not too bad as far as light pollution goes! I am (secretly) eyeing off a 16" Dob and may move on my 10" but we'll see how that goes! THanks for getting back to me and I appreciate the advice! I will look into the OIII/NB filter (do you recommend any?). One day, we should catch up as we live not far from each other! I am not far from the Logan Hyperdumb......Hey quick question, would a 10" dob with quality eyepieces be better than a 16" telescope...if I have the chance to get one cheap enough is the size (it will stay put in my backyard) worth it??
Regards
Andrew H
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Old 29-12-2016, 10:18 AM
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Hi Malcolm
I have read quite a few of your excellent posts and it is going to take me some time to digest this! Luckily I am the study and contemplative type, which of course draws me to the stars! Thanks for your time and I will ponder this! I am eyeing off a 16" Dob that I have the chance to pick up quite cheap....lol....temptations!
Regards
Andrew H
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Old 29-12-2016, 10:21 AM
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Originally Posted by Allan_L View Post
Hi Andrew.
Welcome to IceInSpace
Congratulations on a great scope purchase.

I agree with wavytone. Dont write off your supplied plossls.
However, for when you have more money than you need ...
For my 10" DOB I found my Televue Panoptic 27mm was best for most (large) DSO's.
For a cheaper alternative I found Vixen LVW's to be nearly as good for a lot less.

The 13 Nagler will be a good general eyepiece (very very good actually)

And as Wavy said 4 to 6mm for planetary detail. Here, plossls are a bit tight, so I have used TV Radians (but these are no longer sold new). Alternative, use a good barlow with you 13 Nagler might even be better.
Once you have studied Saturn and Jupiter, I don't think you will have much use for high magnification, so seems a bit of a waste to spend too much on this end of the range.

Too many choices.
See if you can find a local observing group and see what they are using, and test them in your scope.
Thanks kindly for that and I have seen the Panoptic eyepieces and will consider that for a good workhorse eyepiece. I would rather buy 3 or so really good pieces but use them (and really love them) than put money into cheapo stuff. I was wondering about Barlows....whether I do that instead of getting a 5mm Televue (delite maybe)...a lot of variables and things to consider in this hobby!
Regards
Andrew H
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Old 29-12-2016, 11:27 AM
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Hi Andrew, and welcome to the hobby!

I have a 13mm NaglerT6 as well, and it is probably my most-used eyepiece. It barlows very well (I also have the TV 2x barlow) and gives very good contrast in high-power views: so a good barlow may be an easy way of giving you your desired views of the planets. A good thing about a barlow is that it increases the eye-relief a bit, which makes it easier if you wear glasses.

The high-power plossls and orthos can give fantastic, sharp and contrasty views but they have very small eye-relief and this can make it very difficult for eye-glass wearers. They also have rather narrow fields of view- and although this isn't an issue for small objects like planets, it does mean you have to move the scope more often to keep the object in the field of view.
If you want to go down the Ortho path for arguably the best planetary views, I would suggest the Fujiyama 5mm or 6mm: very well priced, but of course a narrow FOV and limited eye-relief. (See Astronomy and Electronics Centre for these.)

Another option for high power is the 6mm from the Long Perng "planetary" series. As far as I know these are identical to the Orion "edge-on" planetary eyepieces and the Williams ones, but they are about 1/2 the price (try Andrews Communications). They have a 20mm eye-relief and a better field of view than standard plossls or orthos. They have good contrast and are very sharp.

Finally, another high-power eyepiece that I haven't seen mentioned in this thread is the Takahashi LE series (see Astronomy and Electronics Centre). Very sharp and high contrast, but they are quite expensive- although they occasionally come up here in the second-hand section.

All the best,

Dean
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Old 29-12-2016, 11:32 AM
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Originally Posted by SkyWatch View Post
Hi Andrew, and welcome to the hobby!

I have a 13mm NaglerT6 as well, and it is probably my most-used eyepiece. It barlows very well (I also have the TV 2x barlow) and gives very good contrast in high-power views: so a good barlow may be an easy way of giving you your desired views of the planets. A good thing about a barlow is that it increases the eye-relief a bit, which makes it easier if you wear glasses.

The high-power plossls and orthos can give fantastic, sharp and contrasty views but they have very small eye-relief and this can make it very difficult for eye-glass wearers. They also have rather narrow fields of view- and although this isn't an issue for small objects like planets, it does mean you have to move the scope more often to keep the object in the field of view.
If you want to go down the Ortho path for arguably the best planetary views, I would suggest the Fujiyama 5mm or 6mm: very well priced, but of course a narrow FOV and limited eye-relief. (See Astronomy and Electronics Centre for these.)

Another option for high power is the 6mm from the Long Perng "planetary" series. As far as I know these are identical to the Orion "edge-on" planetary eyepieces and the Williams ones, but they are about 1/2 the price (try Andrews Communications). They have a 20mm eye-relief and a better field of view than standard plossls or orthos. They have good contrast and are very sharp.

Finally, another high-power eyepiece that I haven't seen mentioned in this thread is the Takahashi LE series (see Astronomy and Electronics Centre). Very sharp and high contrast, but they are quite expensive- although they occasionally come up here in the second-hand section.

All the best,

Dean
Hi Dean
Thanks very much and any information like this is gold! I don't know what it is about the sky at night, but it is a beautiful and compelling thing! It is ancient and mysterious! Okay the Barlow option might be a cheaper way then buying a 5mm good quality lens anyway. I will look into those other brands as I have only really looked at Televue and equivalent stuff (but not prepared to spend $600 or so on a single lens just now!). I will read through your information later today as I have an important PhD report to get submitted by lunch and astronomy just seems so appealing at the moment!
Regards
Andrew H (QLD, Australia).
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Old 29-12-2016, 02:11 PM
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Hi Patrick
I live in Cornubia and it is not too bad as far as light pollution goes! I am (secretly) eyeing off a 16" Dob and may move on my 10" but we'll see how that goes! THanks for getting back to me and I appreciate the advice! I will look into the OIII/NB filter (do you recommend any?). One day, we should catch up as we live not far from each other! I am not far from the Logan Hyperdumb......Hey quick question, would a 10" dob with quality eyepieces be better than a 16" telescope...if I have the chance to get one cheap enough is the size (it will stay put in my backyard) worth it??
Regards
Andrew H
Hi Andrew,
I'm just the other side of the freeway at Tanah Merah, less than 1km from the 'dome. I bought a DGM Optics NPB filter after reading a lot of reviews, and haven't been disappointed - they're a very good filter. I also have some OIII filters which are pretty good, but the DGM NPB tends to give a less "green" overall effect. I had it out last night looking at Orion and the filter made a world of difference. I can't comment on the eyepieces vs larger scope issue - I've currently got an 8" dob, and my 16" dob is arriving (hopefully) in the next few weeks, which will certainly make things a lot brighter/bigger, but I haven't tried enough eyepieces to make an informed decision regarding the benefits of more expensive EP's over larger aperture. A 16" dob at <F5 is probably going to warrant some better eyepieces + coma corrector to get the most out of it. You sound like you've got a pretty reasonable start with the Nagler though! I normally use a Baader 8-24mm zoom, which saves me having to swap eyepieces all the time, and although it's not in the televue class, it's a lot better than the standard plossls you get with a scope. As either Malcolm or Allan said, once you've seen Jupiter and Saturn at high mag, there probably aren't a lot of other objects that justify an expensive high mag eyepiece unless you've got super seeing conditions all the time. Yeah, we should catch up once one of us has a 16"!
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Old 29-12-2016, 02:33 PM
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16"?? nice!

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Hi Andrew,
I'm just the other side of the freeway at Tanah Merah, less than 1km from the 'dome. I bought a DGM Optics NPB filter after reading a lot of reviews, and haven't been disappointed - they're a very good filter. I also have some OIII filters which are pretty good, but the DGM NPB tends to give a less "green" overall effect. I had it out last night looking at Orion and the filter made a world of difference. I can't comment on the eyepieces vs larger scope issue - I've currently got an 8" dob, and my 16" dob is arriving (hopefully) in the next few weeks, which will certainly make things a lot brighter/bigger, but I haven't tried enough eyepieces to make an informed decision regarding the benefits of more expensive EP's over larger aperture. A 16" dob at <F5 is probably going to warrant some better eyepieces + coma corrector to get the most out of it. You sound like you've got a pretty reasonable start with the Nagler though! I normally use a Baader 8-24mm zoom, which saves me having to swap eyepieces all the time, and although it's not in the televue class, it's a lot better than the standard plossls you get with a scope. As either Malcolm or Allan said, once you've seen Jupiter and Saturn at high mag, there probably aren't a lot of other objects that justify an expensive high mag eyepiece unless you've got super seeing conditions all the time. Yeah, we should catch up once one of us has a 16"!
Wow! 16" will be a big step up from an 8" indeed! Man would love to see the view through that! It's funny as I was eyeing off a second hand 16"and moving my 10" on!! Thanks for the filter advice, I will hunt one down I think. By the way do you have your (or will you) have your 16"set up in a permanent spot? Do you star gaze often? What objects or things do you view most often or what inspires you with astronomy? To be honest I haven't seen much yet but then again I am still learning where things are and how to use my equipment, although I don't like my dodgy eyepieces that came with my Skywatcher 10"....Logan seems to be not too bad for viewing..hopefully a good sky tonight!!
Regards
Andrew H
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Old 29-12-2016, 03:03 PM
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Hi Dean
Thanks very much and any information like this is gold! I don't know what it is about the sky at night, but it is a beautiful and compelling thing! It is ancient and mysterious! Okay the Barlow option might be a cheaper way then buying a 5mm good quality lens anyway. I will look into those other brands as I have only really looked at Televue and equivalent stuff (but not prepared to spend $600 or so on a single lens just now!). I will read through your information later today as I have an important PhD report to get submitted by lunch and astronomy just seems so appealing at the moment!
Regards
Andrew H (QLD, Australia).
Good luck with that report Andrew. I always found when essays or reports were due that even vacuuming the house had more appeal!

All the best,

Dean
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Old 29-12-2016, 03:33 PM
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Good luck with that report Andrew. I always found when essays or reports were due that even vacuuming the house had more appeal!

All the best,

Dean
LOL..got it submitted! When I say submitted, that is it will come back with comments and edits to be done! I have my doctoral confirmation at the end of January, so it has been a working Christmas! I am going through your other post...cool information there. I like the Barlow 2X idea...cheaper than a high powered lens! Interesting hobby this one although I am still working out where to find stuff! LOL...however I have been interested in astronomy for ages but just haven't had a chance to start!
Regards
Andrew H
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Old 29-12-2016, 03:50 PM
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LOL..got it submitted! When I say submitted, that is it will come back with comments and edits to be done! I have my doctoral confirmation at the end of January, so it has been a working Christmas! I am going through your other post...cool information there. I like the Barlow 2X idea...cheaper than a high powered lens! Interesting hobby this one although I am still working out where to find stuff! LOL...however I have been interested in astronomy for ages but just haven't had a chance to start!
Regards
Andrew H
Hi again Andrew. Have you looked in the IIS classies? 2xTV barlow: http://www.iceinspace.com.au/forum/s...d.php?t=149891
It has been there for a while...
- a couple of Tak LE 7.5's too.

- and congratulations on the PhD! What field?

- Dean
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Old 29-12-2016, 04:08 PM
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Hi again Andrew. Have you looked in the IIS classies? 2xTV barlow: http://www.iceinspace.com.au/forum/s...d.php?t=149891
It has been there for a while...
- a couple of Tak LE 7.5's too.

- and congratulations on the PhD! What field?

- Dean
Thanks Dean
I have dropped that guy with the TV 2X Barlow a line...I was actually chasing one (along with my second hand 13mm Nagler TV would do nicely...what else do I need??? hmm!
My Phd is with Griffith University, doing it on adoption within Australia. An interesting topic that deals with real people being moved about, and the life issues and identity factors that they then deal with! Another solid 2 years to go (at least!). At least I got a full time scholarship so it is generally not a bad life, but has its very intense moments. Perhaps Astronomy is a way to unwind I think,,,,I find that whenever I am outside in the cool dark air, I feel so much better!
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Old 29-12-2016, 04:16 PM
ausastronomer (John Bambury)
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Several people have advised you on a 4mm to 6mm eyepiece at the high power end.

I am assuming your scope is a 10"/F4.7 with a 1200mm focal length?

I would advise you in the first instance to go with a 7mm or an 8mm eye piece as opposed to a 4mm to 6mm eyepiece. An 8mm eyepiece will give 150X and a 7mm eyepiece 172X in that scope. This compares to a 6mm eyepiece giving 200X, a 5mm eyepiece giving 240X and a 4mm eyepiece giving 300X.

Depending on the area you observe and its prevailing weather conditions and topography there are many nights where you cannot get to 200X in a 10" Newtonian, but can get to 150X to 180X. This would mean that a 7mm or an 8mm eyepiece would see a lot more use than a 4mm to 6mm eyepiece. With a non tracking scope the slightly longer focal length eyepiece is a also a bit easier for a newcomer to use and keep the target well within the FOV.

When you expand your eyepiece collection past 3, most definitely get your self a 5mm, or 6mm eyepiece as it will certainly get used on nights of good seeing and you will appreciate the extra power on those nights. It's just not where I think you need to go considering you don't have something to give you around 150X, which can quite often be your upper limit with a 10" scope under less than ideal seeing, or if your optics have not thermally stabilised.

There are plenty of choices out there and it all comes back to budget and personal preference. You usually get what you pay for. There are certainly some good second hand bargains that come up from time to time and that will often get you a premium 2nd hand eyepiece for the price of a mediocre new one in the $200 to $300 price range. Used Televue Radians are good choice on the 2nd hand market, as are Pentax XW's and Vixen LVW's. These have a medium wide field and long eye relief combined with excellent optical performance. Whilst good orthoscopics and plossls are good eyepieces optically they aren't any better optically than the eyepieces I have mentioned and they aren't as easy for a beginner to use in a non tracking dobsonian.

At the longer focal length end a 27mm Panoptic is about as good a low power finder eyepiece as you will find for a 10" dobsonian, without breaking the bank.

Cheers
John B
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Old 29-12-2016, 04:43 PM
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Wow! 16" will be a big step up from an 8" indeed! Man would love to see the view through that! It's funny as I was eyeing off a second hand 16"and moving my 10" on!! Thanks for the filter advice, I will hunt one down I think. By the way do you have your (or will you) have your 16"set up in a permanent spot? Do you star gaze often? What objects or things do you view most often or what inspires you with astronomy? To be honest I haven't seen much yet but then again I am still learning where things are and how to use my equipment, although I don't like my dodgy eyepieces that came with my Skywatcher 10"....Logan seems to be not too bad for viewing..hopefully a good sky tonight!!
Regards
Andrew H
Yeah, I figured if I'm gonna get more aperture, scratch the itch once and for all! I won't have it permanently set up - probably lug it out/roll it out when required. I try to get my scope out maybe once a week, weather permitting, but when the moon is anywhere near full it's pretty pointless at my place for anything other than viewing the moon itself. Once a month near the new moon I try to get out to a comparatively darker site which makes a big difference on fainter DSO's - this is usually with a facebook group called AstroAnarchy who have several wise heads there who can answer a lot of questions.
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Old 29-12-2016, 04:46 PM
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Originally Posted by ausastronomer View Post
Several people have advised you on a 4mm to 6mm eyepiece at the high power end.

I am assuming your scope is a 10"/F4.7 with a 1200mm focal length?

I would advise you in the first instance to go with a 7mm or an 8mm eye piece as opposed to a 4mm to 6mm eyepiece. An 8mm eyepiece will give 150X and a 7mm eyepiece 172X in that scope. This compares to a 6mm eyepiece giving 200X, a 5mm eyepiece giving 240X and a 4mm eyepiece giving 300X.

Depending on the area you observe and its prevailing weather conditions and topography there are many nights where you cannot get to 200X in a 10" Newtonian, but can get to 150X to 180X. This would mean that a 7mm or an 8mm eyepiece would see a lot more use than a 4mm to 6mm eyepiece. With a non tracking scope the slightly longer focal length eyepiece is a also a bit easier for a newcomer to use and keep the target well within the FOV.

When you expand your eyepiece collection past 3, most definitely get your self a 5mm, or 6mm eyepiece as it will certainly get used on nights of good seeing and you will appreciate the extra power on those nights. It's just not where I think you need to go considering you don't have something to give you around 150X, which can quite often be your upper limit with a 10" scope under less than ideal seeing, or if your optics have not thermally stabilised.

There are plenty of choices out there and it all comes back to budget and personal preference. You usually get what you pay for. There are certainly some good second hand bargains that come up from time to time and that will often get you a premium 2nd hand eyepiece for the price of a mediocre new one in the $200 to $300 price range. Used Televue Radians are good choice on the 2nd hand market, as are Pentax XW's and Vixen LVW's. These have a medium wide field and long eye relief combined with excellent optical performance. Whilst good orthoscopics and plossls are good eyepieces optically they aren't any better optically than the eyepieces I have mentioned and they aren't as easy for a beginner to use in a non tracking dobsonian.

At the longer focal length end a 27mm Panoptic is about as good a low power finder eyepiece as you will find for a 10" dobsonian, without breaking the bank.

Cheers
John B
Thanks John
Another great response and more to think about. A few people have advised a quality Barlow (2x) Televue that I am eyeing off (second hand) to go with my 13mm Nagler TV...which would give me that high magnification aspect that my 10" would probably just manage (as you mentioned). Still debating whether a separate piece at say 7mm or the 2X Barlow which would give about 6.5mm...what do you think on this issue? A dedicated piece at about the 7mm or a Barlow? I can get the TV Barlow 2x at about $130 which is not bad.
Your profile mentions you are in the Hunter Valley region of NSW? How is the viewing down there?
Thanks for any advice, this site has been excellent and I am really enjoying getting to learn all this new knowledge, there seems to be a bit to learn!
Andrew H
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Old 29-12-2016, 10:14 PM
ausastronomer (John Bambury)
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Join Date: Mar 2005
Location: Shoalhaven Heads, NSW
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Originally Posted by FourOwls View Post
what do you think on this issue? A dedicated piece at about the 7mm or a Barlow? I can get the TV Barlow 2x at about $130 which is not bad.
Hi Andrew,

I think you should probably give serious consideration to making an offer on one of the 7.5mm Takahashi LE's currently on sale in the classifieds. There are 3 of them advertised there right now, a used one and 2 NIB. I have used the used one that James Pierce is selling and it is in excellent condition and an excellent eyepiece. It's actually his wife Alex's and he stole it off her

Quote:
Originally Posted by FourOwls View Post
Your profile mentions you are in the Hunter Valley region of NSW? How is the viewing down there?
Andrew H
Nope. I lived on the Central Coast for 12 years and was a member of the AS of The Hunter for some years, but I moved to Kiama on the South Coast 6 years ago. 4 months ago I moved 20km further South to Shoalhaven Heads. There are some excellent observing sites in the Hunter region and just south of it around Bucketty.

Cheers,
John B
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