Nagler Zoom vs Takahashi LE?

[Profiler (Profiler)]

I would be very grateful to hear the thoughts of other IIS members concerning their experiences/views/opinions with either the Televue 3-6mm Nagler Zoom or the Takahashi LE 5mm?

I am looking to invest in one premium quality eyepiece for planetary observing and like both of these EP's but simply can't decide which might be the better purely in terms of optical performance.

Both have 10mm ER and the TV Zoom has the range of adjustable focal lengths (whereas the LE can be barlowed etc) but I have difficulty believing that a zoom eyepiece can genuinely rival the optical performance of a fixed focal length EP let alone a Tak LE. I make this last point because the one review I am able to find doing a head to head comparison of these two eyepieces actually seems to indicate that the TV zoom set at 5mm was better than the 5mm Tak LE.
see http://www.cloudynights.com/item.php?item_id=336

[Steffen]

Considering the price of the Tak vs the Nag ($300 vs $450) I'd go with the Tak first. If you later on decide a zoom is worth the extra cash you can sell the Tak - as you know there are not too many 2nd hand ones going around

I've never looked through the 3-6 Nag, so take this for what it's worth…

Cheers
Steffen.

[astro744]

The Tele Vue 3-6mm Nagler zoom is one of my favourites since it allows me to dial in just the right amount of magnification. There are click stops at 3,4,5 & 6mm but you can also dial in any focal length in between. The image quality is superb but I do not have a Tak LE to compare.

I would get the zoom first and this will give you an idea of what focal lengths work for you best. Then if you don't like the zoom you can invest in those fixed focal lengths and sell the zoom. However, I doubt you will ever sell it as it is just so versatile.

[Profiler (Profiler)]

Hello Steffen & Astro744

I am very appreciative of both your comments. The frustrating thing for me is I can't try or compare before I have to buy. Both the TV Nagler Zoom and Tak LE’s come with equal praise. The Nagler zoom costs a bit more but I would expect it to given it can change to other focal lengths.

I am thinking of this choice purely in terms of one long-term investment (irrespective of price) for an eyepiece that will give me optimal overall optical performance and still has at least 10mm of ER.

Both the Tak LE and the Nagler zoom use 5 lens elements in three groups. Ironically, my suspicion is that the LE 5mm would optically be the better eyepiece at the 5mm focal length. However, herein begins my consternation.

While the Tak might be better at 5mm to get it to other focal lengths will require barlows etc and in essence I am introducing more lens elements which will potentially diminish it’s performance at other focal lengths. Thus, while the Tak LE might be better at 5mm, the Nagler zoom might actually be optically superior overall because it achieves all possible focal lengths utilising only its original 5 lens elements.

Any ideas/opinions from anyone on this?

[issdaol (Phil)]

Hi Profiler,

I can personally vouch for the quality of the Tak LE5 and I find that it has very good contrast and sharpness and very coulor neutral. The ER is 10mm and FOV of 52 deg. I have not compared it to a Variable Nagler so cant advise from that point of view.

However I would suggest if you need variable FL's then the Tak is not suitable no matter how good it compares, unless you want to buy multiple fixed FL eyepieces in the ranges you are looking at for the Nagler Zoom.

Cheers

[Profiler (Profiler)]

Hi Phil

I appreciate the vote of confidence in the LE's.

I agree that in a stand-alone comparison the LE 5mm is probably better than the TV Nagler Zoom at a 5mm setting. However, based upon the praise for the Nagler Zoom I suspect this margin of superiority at a 5mm setting alone is likely to be close.

However, what I am really keen to know about is what is the optical performance of an Tak LE likely to be when coupled with some sort of good quality barlow? Will this margin of superiority in the LE remain when coupled with barlows and thus introducing many more lens elements?

The reason I pose this question is that I am primarily thinking of using either a 5mm LE or TV Nagler Zoom with some super short focal length refractors like the TV-60 or Tak FS-60CB which both only have about 360 F/L. Consequently, to get up to some higher magnifications I will need something like the 3-6 Nagler Zoom or a LE 5 or 7.5mm coupled with a barlow.

Both the TV Zoom and LE's have good reputations, use 5 lens elements in three groups, have 10mm of ER and the TV Zoom has 50 vs 52 AFOV in the LE. However, getting to the crux of things - what will the optical quality of the LE's be like when coupled with a barlow/powermate/extender Q to acheive a shorter focal length which the TV Zoom can achieve with it's original 5 lens elements?

Any thoughts?

[astro744]

Originally Posted by Profiler

The reason I pose this question is that I am primarily thinking of using either a 5mm LE or TV Nagler Zoom with some super short focal length refractors like the TV-60 or Tak FS-60CB which both only have about 360 F/L. Consequently, to get up to some higher magnifications I will need something like the 3-6 Nagler Zoom or a LE 5 or 7.5mm coupled with a barlow.

You know the 2-4mm Nagler zoom was made for just such a short APO and yes it is as good as the 3-6 but has click stops every half mm. This way you avoid Barlows altogether.

[Profiler (Profiler)]

Hi Astro,

Yes - I know about the 2-4mm TV Zoom but for a variety of reasons I actually think the 3-6 Zoom is the better option. Although 2-4mm Zoom has the click stops every half mm I can't imagine too many occasions when I might practically be able to use it between 2-3mm settings even with a TV-60 or FS-60. Hence, the 3-6 Nagler zoom sounds like the better option. What I would really like is some feedback/comments on what the optical quality of a Tak LE barlowed to the equivalent of approximately 3mm would be liked compared to a TV zoom at a 3mm setting?

[issdaol (Phil)]

Hi Profiler,

With my current setup I do not really need to use a Barlow as my LE5mm and LE 7.5mm give me 714x and 476x on the Mewlon 300. Also with my my prior SCT systems I did not need to use a Barlow either. So I have not tested my LE5 with a Barlow to compare.

My prior personal experience with Barlows on older refractors was not that good but I know that Barlow quality is much better now that what it used to be when I first used them.

I have heard that both theTV Nagler 2-4 Zoom TV Nagler 3-6 Zoom are very good and may be more flexible for your use.

Consider that for your FL and Aperture using Tak FS60 a theoretical maximum usable magnification of around 100x per inch:

1. With a Native TV Nagler 3-6 zoom you will achieve

60x, 72x, 90x, 120x

2. With a Native TV Nagler 2-4 zoom you will achieve

90x, 120x, 180x

3. With a Native Tak LE5 you will achieve

72x


If you go down the fixed Eyepiece Path you will need 3 different eyepieces (perhaps Tak LE5, Tak HI-LE 2.8 , Tak HI-LE 3.6) to achieve:

128x, 100x, 72x

You will also then need to consider a high quality Barlow/Tele-extender.

Either way assuming comparable optics the TV 2-4 Zoom or maybe the TV 3-6 Zoom seem a more flexible option.

Cheers

[Profiler (Profiler)]

Hi Phil,

I appreciate the advice. It seems like, reading between the lines, that to maintain the optical quality with the LE's essentially means not using a barlow. Hence, buying numerous individual focal lengths rather than using, for example, a good 1.6 barlow on a LE5mm to get roughly 3mm.

[issdaol (Phil)]

Hi Profiler,

Not at all.

The Tak LE eyepieces are very good quality EP's and give excellent visuals and there are many good reviews and users that love them.

Personally I would not trade any of my Tak LE's but would add to my collection with either TV's, Pentax or similar quality EP's.

Just trying to point out that a high quality TV Zoom gives you multiple magnification levels that are potentially doubled by the use of a barlow.

The Tak LE5 on the otherhand gives only 2 magnifications when used with a Barlow.

I the past I have used small APO refractors and from personal experience you can push them only so far with Hi Mag EP's and Barlows before your image quality degrades.

A Tak FS60C with Tak LE EP's will not let you down but at the end of the day it is only a 60mm/355FL system.

However I do know some Tak users that have FS60C and use the Tak Extender Q and Tak LE EP's which gives good results.

Cheers

[Profiler (Profiler)]

Hi Phil

Thanks for the clarification. When I think about it while the LE's are certainly great EP's the Nagler Zoom is far more versatile which is also something I am after. Essentially, to rival the Zoom I will need to invest in numerous fixed focal length EPs. In principle there isn't anything wrong with this but right now I am actually planning towards an ultra portable grab-and-go set-up with OTA, 2-3 EP's + barlow as I travel. The impression I am getting is that the perhaps the best decision will be to ultimately buy both as they both have opposing advanatges and disadvantages which seem most manifest in different contexts and applications.

[issdaol (Phil)]

Hi Profiler,

No problem. Hope my advice has helped with your process :-)

I have been thinking of a quick grab and go like the Tak FS60CB or TAK TSA102 myself.

Thankfully I have most of the other components so I just need a easy to transport tripod & mount.

Cheers

[ausastronomer (John Bambury)]

Originally Posted by Steffen

Considering the price of the Tak vs the Nag ($300 vs $450) I'd go with the Tak first. If you later on decide a zoom is worth the extra cash you can sell the Tak - as you know there are not too many 2nd hand ones going around

I've never looked through the 3-6 Nag, so take this for what it's worth…

Cheers
Steffen.

Considering the price of these two and having used what I have used and knowing what I know, I would be buying the 5mm Pentax XW in a flash. It fits within the price range and is a better eyepiece optically, comfort wise and in terms of FOV, than the two you are considering. If you want the convenience of a short focal length zoom the Nagler 3-6 is an excellent choice, but not the equal of the 5mm XW optically. IMO the 5mm Tak LE is a good eyepiece but not the equal of the 5mm UO HD ortho, which is 1/2 the price of the Tak LE.

Cheers,
John B

[Steffen]

I've always wanted to try a Pentax XW, unfortunately they're even more expensive than Naglers (almost as expensive as the Nagler 3-6 zoom), and much more expensive than Taks.

Maybe I can catch a glimpse through one at IISAC

Cheers
Steffen.

[Profiler (Profiler)]

Hello John and Steffen,

I just came across quite an interesting article which can be easily found via Google - just type in 'Planetary Eyepieces' by 'Daniel Mounsey' and you will find it.

I would be very interested to hear your thoughts on the conclusions of this article. It is perhaps a little dated but basically seems to advocate the Edmund RKE's or some simple TV Plossl's. He gives the Nagler zoom a clear thumbs down, appears to think the LE's are 'okay' as general purpose planetary EP's and that widefield EP's in general - while good in their own right - aren't really suited for planetary observing.

I know the Pentax XO's are meant to be superb 'if' you can manage the ER - which I can't unfortunately. Similarly, the XW's always attract great praise but I can't say they spring up as recommended planetary EP's. I was leaning towards the nagler zoom due to size and being versatile - but if the optical performance leaves a 'lot' to be desired I think I would prefer to look elsewhere.

I am curious to hear what either of you or anyone else make of the Mounsey article.

[astro744]

All I can say I have never been disappointed with the images through my 3-6mm Nagler zoom.

The RKE's are only available down to 8mm. You will need a Barlow to get reasonable magnification on any short 60mm APO refractor. The RKE's are cheap so if you get one you haven't lost a lot if it's no good.

I think perhaps a larger instrument would be a better choice than trying to get the most out of a 60mm APO/eyepiece combination.

[Profiler (Profiler)]

Hi Astro

I was surprised myself by the Mounsey view/review/opinion of the Nagler Zoom as I can think of at least three other reviews from CN's which feature considerable praise for the 3-6 zoom - one of which as I mentioned previously - directly compares the zoom set at 5mm to the 5mm Tak LE and finds in favour of the zoom.

[Steffen]

In the end you have to see for yourself. It can be treacherous to spend a lot of money sight unseen. If you don't get to use an eyepiece before buying maybe it's best not to go for a premium priced one straight away? Wouldn't you hate to find out that your $$$ eyepiece performs only slightly better than something a lot cheaper, in your scope and for your eyes?

What John said about the cheap orthos is very true, they have their quirks but are very hard to beat on planets, esp for the price. I've got three KK orthos and love them. They cost me about $70 each, shipped.

Cheers
Steffen.

[issdaol (Phil)]

Hi Profiler,

I agree with Steffen.

If still in doubt hedge your bets by smaller investement or arrange to beg/borrow the use of someone else's to see for your self :-)

When I bought my setup I was lucky enough to be able to have first hand use of all of the equipment and most of the alternatives before I made my decision.

Cheers