The Best 5mm EP under $200.

[Suzy]

Chris,
Your thread was a great read. Thankyou. I emailed Frontier Optics today for a price on both the WX & the XF, as there are no prices shown on-line. The XF is right within my budget! But...

Originally I was after anything over 50mm fov, but now that I'm more informed, I would prefer around 68-70 fov. I have a 68 fov 15mm- it's just comfortable after barlowing. It's just too hard on a dob anything under, as I want this ep to study with, so I need my view on things for as long as possible.
What would my FOV be with a 10mm, 60 fov, barlowed? I will give it thought though I think i'm going backwards. ?

Anyone? What's the difference between the XF & WX apart from 10 deg fov difference, 2mm less eye relief, and $200 more? They don't give much info on-line.:question :

[Wavytone]

Suzy, you have neatly summed up the difference nicely, the choice is yours.
Evidently field of view is a higher priority for you than contrast.

Personally for high power I would go for contrast and image quality and tolerate a smaller FoV - even if this means swapping eyepieces to recenter the object.

[Suzy]

I'VE JUST COME ACROSS THIS...

The first thing to realise is that for the best in planetary viewing you need very different things to eyepieces used for DSOs (deep space objects), which is where the emphasis is placed on most general purpose eyepieces.

The primary difference is that eyepieces for DSOs are optimised for wide field viewing. To do this they tend to use large numbers of lenses in several groupings which inevitably introduces lateral colour, which is the death knell to seeing fine low-contrast details on the planets. The extra air-glass and glass-glass transitions also introduce more light scattering which causes a halo effect around bright objects. Again, this is not a problem for faint DSOs but a major issue for planetary viewing. The Nagler designs are often presented in a rather lazy manner as being the best eyepiece regardless of the question asked. In reality they perform particularly poorly in planetary use, in large part because of the sheer complexity and number of elements.

True planetary eyepieces are different beasts altogether. The primary job is viewing bright objects with as much detail and contrast as is possible. All other considerations are secondary. There is a strong advantage to minimising the number of elements even if this also reduces the field of view. True planetary eyepeices give much better light transmission, infinitely higher contrast and the absolute minimum scattered light. Space is black with a planetary eyepiece. It is often a murky grey with a wide field design.

For specifics, the Orthoscopic recommended by Andrew S would not be a bad choice but for my money I would go for a TMB Planetary II, which is around the same price but it has the edge even if it is fairly marginal. 5mm is probably about the right focal length. In a perfect world I would have said one of the TMB monocentrics, which really are no compromise planetary eyepeices, with absolutely unrivalled nothing-else-even-comes-close contrast. However, those are out of production now and as a highly specialised eyepiece they are unlikely to reappear on the market for the foreseeable future.
-------------------------------

Question: Will I get a better quality with the Pentax 60 fov, than the 68 fov. Also, the Pentax has 7 elements. Isn't that a lot? This guy is saying here the more fov, and more elements, the less quality. Waveytone in fact said the same thing regarding number of elements. I was hoping the Pentax would be different. I also have a dob, and that's going to be tricky with 60fov. I'm guessing I need to make a choice between being practical and quality.Oh golly, golly just when i thought I was making a decision.

Sorry guys for dragging this thread out for so long...It's just I don't ever intend to spend up like this ever again on an eyepiece. I'm trying to be the best informed before I buy.. thankyou for you help and patience.

[torana68 (Roger)]

maybe your local club could help out ? see if members have the eyepieces and do a road test?
Roger

[Wavytone]

Hi Suzy, it seems you are learning fast.

First, I'll talk about eyepieces assuming you use your current dob, for which 5mm seems ideal for you for high power.

At high power,as you have realised, it's most likely you're looking at something small, on-axis, and a huge field of view is pointless assuming you can re-centre the object. What is more useful is the best image quality and contrast, on-axis.

it is for this reason many lunar and planetary observers are more interested in ep's with as few galss-air surfaces as possible, and would prefer MgF coatings (less scattered light when clean) to the broadband multicoatings (more durable but more scattered light).

The standout is the TMB supermonocentric (SMC) with just 2 glass-air surfaces.

From there its a toss-up between Brandons (best), Zeiss Abbe Orthoscopics (ZAO), Edmund RKE's (excellent bargain IMHO), or the run-of-the-mill ortho's which have 4 glass-air surfaces. Experienced planetary observers have some of these, if not a full set.

All of the widefield designs such as the GSO's, Vixen LVW's, Hyperions, Stratus', Naglers, Ethoi and the Pentax have many more glass-air surfaces and are all multicoated. Yes they give a lovely wide field, but look closely at a star or planet at high power and it's not such a beautiful view if you know what the textbooks say you should see with perfect optics.

Secondly there is the question of the focal ratio of your scope.

Trying to get good planetary images out of a typical f/5 dob is quite frankly fraught with the compromises associated with horribly short eyepieces.

If you want high power it is much better to start with a long focal length telescope (magnification = F/f, where F is the telescope focal length and f is the eyepiece focal length).

For example, for two scopes of the same aperture, one f/5 and the other at f/15, a 5mm eyepiece in the f/5 gives the same magnification as a 15mm in the f/15 scope. But the image quality will be chalk and cheese... an f/5 dob will have a huge secondary (degrades the image), and the 5mm eyepiece is a pain to use (never mind keep clean). An f/15 scope has a far smaller secondary (behaves like an APO refractor) and most 15mm eyepieces are quite comfortable to use.

Even better, almost all modern eyepieces work very well with an f/15 light cone, so there is really no need to splash out on the really expensive ones. On the other hand Brandons and orthos do not work well with scopes faster than f/7, usually they show some pretty horrendous aberrations over the outer third of the field of view.

It is for this reason I use an f/15 Mak, and a set of eyepieces that span 8 - 50mm...

* of the ones I mentioned, the Edmund RKE's were designed specifically for Newtonians at f/4,with respect to the curvature of the field and coma. For fast Newtonians these eyepieces are very much overlooked and they are startlingly good, for what they are.

[Astrobserver99 (Rob)]

I like the TMB Planetary. Great colour and sharpness and easy to use. I use mine with a 2x TV Barlow.

[Suzy]

Waveytone, thankyou for that. My scope is an F/7.8, and I'll assume when you talk about an F/5 that it applies to an F/7.8 as well?

They do not make the Zeiss or the TMB monos anymore.

[Gargoyle_Steve (Steve)]

As per the link posted by Steffen up above, I have a Burgess / TMB Planetary (mine is a 6mm) that I picked up 2nd hand from the adds here on IIS, and it's great in my opinion - I have used it both in my 12" f5 dob and in my 5" f7 reflector (tripod mount, ALT/AZ head). It gives very good planetary views, and naturally the moon is beyond stunning - best views of it I have ever seen.

I own several Baader Hyperion ep's for DSO viewing (36, 24, 17, 13mm.... and another?) along with an 8mm Orion Stratos and a 12mm Pentax XF (which I also LOVE using) but I won't be parting with the TMB, it just does such a great job! If you can get that 5mm as per the Optcorp add, or another one from somewhere else, I'd definitely say go for it.

[Steffen]

Astronomica in the UK have the 6mm TMB new for £55:

http://www.astronomica.co.uk/index.p...-Eyepiece.html

Cheers
Steffen.

[RobF (Rob)]

Originally Posted by Gargoyle_Steve

As per the link posted by Steffen up above, I have a Burgess / TMB Planetary (mine is a 6mm) that I picked up 2nd hand from the adds here on IIS, and it's great in my opinion - I have used it both in my 12" f5 dob and in my 5" f7 reflector (tripod mount, ALT/AZ head). It gives very good planetary views, and naturally the moon is beyond stunning - best views of it I have ever seen.

Haven't seen you for a while Steve, but next time I do I'll have to bug you to do a side-by-side between my 6mm Radian and your TMB! I've always been curious. This is turning into quite an educational thread.

[Wavytone]

Originally Posted by Suzy

They do not make the Zeiss or the TMB monos anymore.

Aah yes, but they come up for sale often enough on Astromart, can pick them up for a song. Most of the sellers will ship to Aus for a few $ more.

[Gargoyle_Steve (Steve)]

Originally Posted by RobF

Haven't seen you for a while Steve, but next time I do I'll have to bug you to do a side-by-side between my 6mm Radian and your TMB! I've always been curious. This is turning into quite an educational thread.

I haven't been around much Rob, I've been having some extended "down time" for a while now, but I hope we can catch up sometime soon. I'd be delighted to do a side by side comparison, and Ron also has a 6mm Radian so I'm sure something can be worked out.

My brother from the Alice is coming down on holidays in May, will be here for new moon, and is bringing his new Ethos with him (13 mm I think?). I haven't seen one of those bazookas live yet, let alone looked through one, so if we can catch up around that time then you can probably have a gander through that as well!

[astro744]

Originally Posted by Suzy

I'VE JUST COME ACROSS THIS...

The first thing to realise is that for the best in planetary viewing you need very different things to eyepieces used for DSOs (deep space objects), which is where the emphasis is placed on most general purpose eyepieces.

The primary difference is that eyepieces for DSOs are optimised for wide field viewing. To do this they tend to use large numbers of lenses in several groupings which inevitably introduces lateral colour, which is the death knell to seeing fine low-contrast details on the planets. The extra air-glass and glass-glass transitions also introduce more light scattering which causes a halo effect around bright objects. Again, this is not a problem for faint DSOs but a major issue for planetary viewing. The Nagler designs are often presented in a rather lazy manner as being the best eyepiece regardless of the question asked. In reality they perform particularly poorly in planetary use, in large part because of the sheer complexity and number of elements.

True planetary eyepieces are different beasts altogether. The primary job is viewing bright objects with as much detail and contrast as is possible. All other considerations are secondary. There is a strong advantage to minimising the number of elements even if this also reduces the field of view. True planetary eyepeices give much better light transmission, infinitely higher contrast and the absolute minimum scattered light. Space is black with a planetary eyepiece. It is often a murky grey with a wide field design.

For specifics, the Orthoscopic recommended by Andrew S would not be a bad choice but for my money I would go for a TMB Planetary II, which is around the same price but it has the edge even if it is fairly marginal. 5mm is probably about the right focal length. In a perfect world I would have said one of the TMB monocentrics, which really are no compromise planetary eyepeices, with absolutely unrivalled nothing-else-even-comes-close contrast. However, those are out of production now and as a highly specialised eyepiece they are unlikely to reappear on the market for the foreseeable future.
-------------------------------

Question: Will I get a better quality with the Pentax 60 fov, than the 68 fov. Also, the Pentax has 7 elements. Isn't that a lot? This guy is saying here the more fov, and more elements, the less quality. Waveytone in fact said the same thing regarding number of elements. I was hoping the Pentax would be different. I also have a dob, and that's going to be tricky with 60fov. I'm guessing I need to make a choice between being practical and quality.Oh golly, golly just when i thought I was making a decision.

Sorry guys for dragging this thread out for so long...It's just I don't ever intend to spend up like this ever again on an eyepiece. I'm trying to be the best informed before I buy.. thankyou for you help and patience.

Whatever applies to planets also applies to deep sky. If you are trying to see that very faint galaxy you are better off with an eyepiece with minimal glass elements, minimal scatter, sharpest on axis, minimal lateral colour and best light transmission otherwise you will not see the galaxy. For galaxies that you can see, such an eyepiece will give you a chance at seeing detail due to better contrast as a result.

Eyepiece design is a compromise and specialist eyepieces designed for planets will also work very well for deep sky. However, they will NOT have the eye relief you desire. They will NOT have the field of view you desire and they will cost more than $200 each.

Eyepieces offered today from companies such as Tele Vue and Pentax are multi-element designs that are needed to provide wide and sharp (both off axis and on axis) views. The glass and coatings used are the finest available and light transmission is only negligibly lower than a simple design if detecable at all.

If you are using an undriven DOB then you will NOT enjoy viewing with a narrow field, short eye relief eyepiece even if it does provide you with the best contrast.

I still recommend the Tele Vue Radian for the following reasons:

1. It is available in 5mm which you wanted.
2. It has a 60deg field of view which you also requested.
3. It has 20mm eye relief which is suitable for eyeglass wearers and is very comfortable for non eyeglass wearers.
4. It is sharp both on axis and off axis. If you ever have a chance to look through one you will see no distortion as a planets drifts from the centre to the edge and finally disappears from view. It is remarkable!
5. All Tele Vue eyepieces are designed to f4 and will work equally well at longer focal lengths.
6. You will get decent views of the band of Jupiter and Saturn with any quality eyepieces (not just a purist's planetary eyepiece) as you also requested.

As an alterative I would recommend the 5mm Nagler to give you the 82deg field that will allow you to view the object that much longer without nudging the telescope. However this eyepiece will cost a lot more than $200. The eye relief is fine for non eyeglass wearers.

I totally disagree with the comment about the Naglers being poor on planetary viewing. One of my best views of Jupiter and Saturn were through a 12mm T4 Nagler on a 10" f6 and 16" f5 telescope. In fact the view of Saturn through the 16" was 'Hubble' quality and you have to remember the eyepiece is but one part of the equation. To get a great view you need good primary optics, good eyepieces, good seeing and a good eye. The final image is only as good as the weakest link. Note I would like to point out that the 16" f5 has premium custom optics and a smaller than usual secondary.

I have never tried a 5mm XW Pentax but being a premium manufacturer I would expect it to perform well. Note neither eyepiece can be bought for $200 but a new Radian is close at $279 and perhaps can be found secondhand for near $200.

The monocentrics are for the purists and do perform well for the task they were designed for, both planetary and deep sky. I do not believe they are the eyepieces you seek or require for you needs and you will be jsut as happy if not more so with other premium eyepieces I have mentioned. Try and get to a star party/group observing session and try as many different eyepieces that are there on the night and you will then know better what you prefer.

Whatever you choose, enjoy!

Originally Posted by Wavytone

Hi Suzy, it seems you are learning fast.

First, I'll talk about eyepieces assuming you use your current dob, for which 5mm seems ideal for you for high power.

At high power,as you have realised, it's most likely you're looking at something small, on-axis, and a huge field of view is pointless assuming you can re-centre the object. What is more useful is the best image quality and contrast, on-axis.

it is for this reason many lunar and planetary observers are more interested in ep's with as few galss-air surfaces as possible, and would prefer MgF coatings (less scattered light when clean) to the broadband multicoatings (more durable but more scattered light).

The standout is the TMB supermonocentric (SMC) with just 2 glass-air surfaces.

From there its a toss-up between Brandons (best), Zeiss Abbe Orthoscopics (ZAO), Edmund RKE's (excellent bargain IMHO), or the run-of-the-mill ortho's which have 4 glass-air surfaces. Experienced planetary observers have some of these, if not a full set.

All of the widefield designs such as the GSO's, Vixen LVW's, Hyperions, Stratus', Naglers, Ethoi and the Pentax have many more glass-air surfaces and are all multicoated. Yes they give a lovely wide field, but look closely at a star or planet at high power and it's not such a beautiful view if you know what the textbooks say you should see with perfect optics.

Secondly there is the question of the focal ratio of your scope.

Trying to get good planetary images out of a typical f/5 dob is quite frankly fraught with the compromises associated with horribly short eyepieces.

If you want high power it is much better to start with a long focal length telescope (magnification = F/f, where F is the telescope focal length and f is the eyepiece focal length).

For example, for two scopes of the same aperture, one f/5 and the other at f/15, a 5mm eyepiece in the f/5 gives the same magnification as a 15mm in the f/15 scope. But the image quality will be chalk and cheese... an f/5 dob will have a huge secondary (degrades the image), and the 5mm eyepiece is a pain to use (never mind keep clean). An f/15 scope has a far smaller secondary (behaves like an APO refractor) and most 15mm eyepieces are quite comfortable to use.

Even better, almost all modern eyepieces work very well with an f/15 light cone, so there is really no need to splash out on the really expensive ones. On the other hand Brandons and orthos do not work well with scopes faster than f/7, usually they show some pretty horrendous aberrations over the outer third of the field of view.

It is for this reason I use an f/15 Mak, and a set of eyepieces that span 8 - 50mm...

* of the ones I mentioned, the Edmund RKE's were designed specifically for Newtonians at f/4,with respect to the curvature of the field and coma. For fast Newtonians these eyepieces are very much overlooked and they are startlingly good, for what they are.

What is the central obstruction of your f15 Mak? I would expect an f15 Mak to have a larger obstruction than an f15 Newtonian.

Originally Posted by Suzy

Could anyone please recommend a really good planetary eyepiece, 5mm, with good eye relief, neutral colour, over 50mm fov, and under $200.

I hear the wide fovs degrade contrast? And I know from experience putting a barlow on degrades quality somewhat, despite having a decent ED one. The 10mm I have at the moment isn't a good one (it came with the scope). Unless you'll can suggest a good 10mm that can handle a barlow ED well. Otherwise, I'll just use the 5mm straight. This will give me 240X on my 6" Dob.

I want to get decent views of the bands on Saturn and Jupiter. I was reading up on the TMB's but one review said it gives a warm and ruddy colour and you get better contrast by staying neutral. And as for the Orion Stratas, a review said there was flaring on the edges. And the Uni. orthos had a lack of eye relief and a small fov so were uncomfortable. I don't care what country I have to get this ep from, my invisible plane is ready to go.

This will be my last ep (yeah, you laugh!), so I want it to be a really good one.

[Suzy]

To Astro 77.... WOW, that was very informative, thankyou.

To Everyone....
I'm upping the budget (why am I not surprised) and will be making a choice between the following two: Pentax XW 5mm or the Vixen LVW 5mm. Most likely the Pentax.

I have at the end of the day only a 6" dob. I only have so much light to play with... are these ep's overkill? Hope that doesn't sound stupid, cause it just did to me!

[Brian W (Brian)]

Hi Suzy I live in the Philippines so I am not up with scope prices where you are. However I am curious how much an 8" scope would cost you. 6x6 +36... 8x8=64 which is almost twice the light gathering potential.

You are talking premier ep's and while they are never over kill maybe a bigger scope might make as much sense?
Brian

[Brian W (Brian)]

Hi again Suzy, As mentioned earlier I use an 8" Lightbridge f/6 as my primary scope. I am currently doing the Herschel 400. My primary ep is the Meade 26mm QX wide.

I use it because with its low power it gives me a nice 'real' fov for star hopping as well as picking up faint fuzzies that my higher power eps have more trouble with.

Certainly it is not useful for fine detail but for colour and for simply finding objects a good quality low power ep may give you more enjoyment as far as galaxies, globular clusters and colours than a high power ep.

Just my opinion because it suits my observing goals for now.
Brian

[torana68 (Roger)]

yep a cheapie (meaning poor quality) barlow means the expensive eyepiece is now a cheapie eyepiece, maybe an 8" 'scope is a better idea, sell yours put the cash into an 8" but I might add the eyepieces are only going to be as good as the mirrors let them be, me Id just get UO HD's, maybe 2 of them and hit someone up for a good barlow for chrissie/birthday/anniversary whatever, I wont be looking at Rolls Royce eyepieces till I have Rolls Royce mirrors

[JethroB76 (Jeff)]

The post this was in response to has changed significantly so I've edited so as not to confuse the thread

[Suzy]

Just thought I would share with you the comparisson specs on the popular eye pieces that you'll recommended.

Make No. Elements/Groups Fov E/Relief

Vixen NLV 9mm 7/4 45 deg. 20mm $169.00

Vixen Lithanum LVW 8mm 8/5 65 deg. 20mm $289.00

Vixen 8-24 zoom,
LV, Lithanum 7/? 40-60 deg. 15-19mm $189.00

Vixen 8-24
Click Stop Zoom 8/4 40-55 deg. 20-15mm $219.00

Vixen NPL (plosl)10mm 4/2 50 deg. 3mm $ 39.95

Pentax XW 10mm (Lithanum)7/6 70 deg. 20mm $309.00

TMB Planetary 9mm 6/4 60 deg. 12mm $125.00

Televue Radian 10mm 6/4 60 deg. 20mm $213.00

Televue Panoptic(24mm) 6/4 68 deg. 70% of F/L $273.00

Ethos ? 100 deg. 15mm $522.00

Nagler Type 4, 12mm 6/4 82 deg. 17mm $330.00

Nagler Type 5, 16mm 6/4 82 deg 62% of F/L $303.00

Nagler Type 6, 9mm 7/4 82 deg 12mm $260.00

Note: The above prices are from OPT with the exception of the TMB which is from Frontier Optics in Sydney. All prices are accurate as of 14/4/2010. OPT is in California U.S. Though they are offering free shipping, it applies to the U.S. only, but said to Australia he would give 20% off me, so I’m sure same that would apply to all if you make mention of that. The Televue incl. Naglers are on sale at this price till 30th April.

[Starkler (Geoff)]

Suzy if you do happen to buy Televue from OS please dont mention it publicly on forum as they have dealer territories to protect and nasty stuff happens if an OS dealer sells to an Aussie and it becomes known.