Which 8mm EP? Nagler or LVW?

[davewaldo]

Hi Everyone,

I currently own 2 good 8mm EPs. The awesome Meade s4000 UWA 8.8 and a Baader hyperion 8mm.

I'm thinking of selling these to fund one EP which would be better.

So I'm trying to decide between the T6 Nagler 9mm or a 8mm Vixen LVW.

The Nagler is the very top of my budget at $300, the Vixen is more like $200.

I like the wide view of the Nagler however I'm wondering if the LVW would have better sharpness just a smaller field and also has better ER. As this EP would be mainly for planetary Obs the field isn't of major importance however I wouldn't want to go lower than 65 degrees.

The eye relief is a bit tight on my Meade 8.8, I like the comfort of the hyperion, but its not as sharp.

This EP will be used in my C8 SCT for the time being but I wouldn't be surprised if I end up going back to a fast Newtonian.

What do the wise people of Ice In Space recommend?

Cheers,

Dave.

[davewaldo]

I just found this which is an interesting read....

http://www.vixenoptics.com/PDF/lvw_review.pdf

I think I'm leaning towards the LVW.... :)

[Dave47tuc]

Dave,
I had a LVW 8 mm its a very nice eyepiece indeed. Great eye relief and nice sharp stars across the field. Well worth getting.:thumbsup:

If you want to sell the Meade 8.8mm Pm me ;)

[Starkler]

You should also consider the 8mm Pentax XF.

[JethroB76]

Was ready to add this too, but he said 65 degree minimum..great quality though, besides 60 is close and I don't miss the extra fov

[davewaldo]

I think the XF is starting to get a little narrow FOV wise.... I didn't really want to go to 65, but I could if it means more comfort and quality.

Originally I was planning to upgrade to the Nagler, but after reading some reports I'm wondering if there is a better EP (like the LVW). I'm basically after something which is optically superior to my meade 8.8, and if that means sacrificing some FOV so be it.

[PhilW]

If you need wide FOV & good eye relief, what about the Pentax XW 7? It is a superb eyepiece. It is a nudge over your budget at around $350, but it is truly worth it, imho. Great planetary eyepiece as well as for DSOs.

If that focal length is too short, then perhaps the XW 10? Another masterpiece from Pentax, good for both DSOs and planets.

[Miaplacidus]

The choice for me would be between a Pentax or the LVW. I have the LVW 5 and 8, and for a while I also owned a Radian 5. Basically the LVW 5 is better than the Radian 5, although quite a bit heavier. The LVW 8 is as good as the LVW 5.

But the Pentax EPs in these short FLs are, well, perfect.

[davewaldo]

So... I'm still not sure which way to go... :)

A) Keep the Meade UWA and buy a planetary EP (ortho, plossl, XF? etc)
B) Sell both and get a Nagler or Pentax XW if I can afford it
C) Keep the Meade and get a LVW, if its better all round, sell the meade.

Basically, what I really want to know is: Will I be missing out on some detail on planets if I go with the Nagler or XW compared to a simpler design like a plossl or ortho?

I would like this to be one of my last EP purchases for quite some years....

At the moment I'm leaning a little towards option A.

Thanks everyone for comments so far!

Dave.

[Paddy]

I don't know how big the LVW 8mm is, but I have a 9mm nagler and 17 mm LVW. I like both ep's but the nagler is much more compact. When I think about getting another ep its usually a nagler that comes to mind, for size and fov. On the issue of detail, I notice that I can see a little more detail on faint galaxies with a plossl vs either the nagler or lvw, but I've never checked to see whether it makes a difference on planets.

[tnott]

The Vixen is probably just as sharp off-axis as the nagler and pentax at F10. If you change to a Newt at f5 or below than it won't be. The nagler has a wider field but the pentax has longer eye-relief.

With modern multi-coatings the difference in light-throughput between these last 2 compared to the lesser element designs is negligible.

Also, the T6mm 9mm nagler is much sharper on-axis than the original - if you can tell the difference between this and a specialised planetary eyepiece then you have better eyes then me. They are cheaper though.

BTW - have you considered the Burgess/TMB Planetary series or radians if it is just for planetary work?

[davewaldo]

Thanks guys, if I end up with just one EP, it needs to be an all rounder so its not just for planetary work. Unless I go for option A in which case I will have only $150 to spend on a dedicated planetary EP, so Radians are out of the picture. :)

What do most people regard as the best EP for planets? <$150. I hear orthoscopic EPs are well regarded.

[Rodstar]

One factor not discussed so far is the amount of use you will get from the eyepiece as seeing conditions vary. You will get a bit more use, I would expect, from a 9mm EP over an 8mm EP when using an SCT, which likely is at f/10. In my SCT days I rarely went below 13mm, actually (except when doing double star work).

Obviously if you were to perform a shoot out between any 8 and 9 mm EPs, the 8 mm EP will be assisted in the comparison by greater contrast/darker background with the slightly higher magnification.

I have a 9 Nagler, and I absolutely adore it. It is so compact, yet produces lovely wide views of deep sky objects and sharp views of planets/luna.

The price of Televue products at the moment is astonishing. I would be jumping at the 9mm Nagler in your price range.

It is a shame that the 8 Ethos is out of your range. Now that would be a treat!

[skies2clear]

Good recommendation. The XW's are superb and you will not want to part with them. Excellent eye relief, comfort, optical performance. Like Phil said, if the 7XW is too much mag for your SCT, then the 10XW will be great. It might hurt your pocket a bit more at the start, but you'll be happy in the long run. Later, you may consider the 7 and 10 as partners together, if you can manage. With Ethos-mania out there, you may in fact pick up one of these used, but in excellent condition, with a substantial saving, as I did,

Clear skies
Nick

[PhilW]

Well, I have an Ethos (13mm), but am definitely not selling my Pentaxes.

btw I see there is an XL 7mm for sale at $230 in the classifieds (ad 348302). This is the old model with a 65-degree FOV; still a great eyepiece.

Dave, one thing you didn't mention is if you wear glasses for observing, e.g. for astigmatism. If so, the greater eye relief of the Vixens & Pentaxes makes them more useable than Naglers.

[madtuna]

I think all the televue Naglers take Dioptrx for eyeglass wearers..though it is an added cost.

I have to admit I love my 13 and 8 mm ethii

[davewaldo]

Thanks everyone for your input.

I do wear glasses but not for observing (no astigmatism). So thats not too much of an issue. Although I do like a comfortable EP.

I would love to purchase a Pentax 10mm UWA if I would be confident that that planetary detail and contrast would be on par with a dedicated planetary EP such as an ortho. Otherwise I plan to just stick with my Meade and buy a couple of orthos.

I'm just not confident that any EP (even the pentax) can do "everything" perfectly. Eye relief, FOV, Contrast and detail/sharpness. Thats why I'm leaning towards 2 EPs, One with a wide view for DSO etc, and one narrow view (ortho?) planetary ep.

But maybe I'm worrying about things too much....

[Starkler]

You mean a Pentax XW?

You are right in that no one eyepiece is perfect in every respect, but the 10mm XW is pretty damn near it and has many votes as being the single best wide-field eyepiece available. Every bit as sharp as an ortho and with contrast unmatched by any other wide-field.



Certainly looks that way!

[matt]

The Pentax XW10 works beautifully with my C9.25.

I also have the XW7...but rarely get to use it due to the need for very good seeing when working at that focal length and magnification.

[ausastronomer]

Hi Dave,

The 10mm Pentax XW is as close to the "perfect" all round eye piece that you will find. It is a slightly better performer than the 9mm Nagler T6 and will outperform your S4000 8.8mm Meade UWA by about 11 light years. That's conservatively. I also have a 9mm University Optics HD ortho and the 10mm Pentax XW outdoes the HD ortho by a miniscule amount. So unless you're going to shell out big bucks for a Brandon or Zeiss Abbe ortho, forget about a cheaper ortho outdoing the 10mm XW. Something else to consider is that an 8" SCT will rarely if ever be in a position to show that something better than a 10mm Pentax XW may exist.



It comes as close to being perfect at everything as any widefield eyepiece. As I mentioned before unless you are shelling out big bucks for Zeiss orthos, aspherics or monocentrics, the AP SPL's, Brandons or Nikon orthos, the 10mm XW will equal all of the cheaper planetary designs. The Tak LE's and TV plossls outdo it by a fraction under superb conditions in a premium scope. I could pick that about twice a year in my 18" Obsession. You would probably never pick it in an 8" SCT for several reasons. Including thermal issues with the corrector plate and the closed tube design and the resolution limitations of an 8" telescope.



Yep, you're jumping at shadows. You can buy the 10mm Pentax XW with confidence and enjoy it. In addition, I think it is the optimum focal length for high power planetary viewing in your scope. Certainly a better choice than a 7mm, 8mm or 9mm eyepiece IMO.

Cheers,
John B

[PhilW]

I think Rod & Matt have made an excellent point. I use my XW 7 all the time for all kinds of viewing, but my focal length is a mere 1.6 metres, so it is generates 230x in my scope. That's as high as I want to go on average nights. An XW 10 in your C8 would produce 200x (corrected); again, probably about as high as you want to go on most nights.

A good place to buy any of these Japanese eyepieces is here:

http://www.kkohki.com/English/kkohkiparts.html

Barry Gooley is the manager & he is great to deal with. :D

Oh, I think John posted at the same time I did. I agree with all his comments - except, I think it will outperform the Meade by 12 light-years.

[ausastronomer]

Phil,

The C8 has a 2000mm focal length, not a 2500mm focal length. Hence the 10mm Pentax XW gives 200X in that scope, which I think is just about perfect, given the cooldown issues of the SCT design.

Cheers,
John B

[PhilW]

Right, it is indeed 200x - all this cloudy weather is getting to me. :doh:

[davewaldo]

Thankyou both Phil and John for your excelent information. This is exactly what I wanted to know.

I know that I seem to be over analysing the situation, especially given that I'm using a C8. However I do like to spend my money wisely and I do plan to buy a premium scope one day soon. I don't like to be constantly upgrading by small amounts.

It looks like the pentax 10mm XW would keep me very happy for some time to come.

Thank you to everyone who posted! Its been most informative :)

Cheers,

David.

PS. Thanks for the link Phil, that where I would be purchasing from.

[Miaplacidus]

You'll be waiting a long time if you want to pick up a Pentax 10 XW second hand. I guess that tells you something...