Naglers - some more notes and some piccies !

[John]

Well my 7mm type 1 Tele Vue Nagler arrived today and it’s cloudy tonight with a forecast of 2 days of poor weather .

I thought I would add a few notes to my earlier report on the 5mm and 13mm type 6 Naglers comparing them to the 7mm type 1, at least physically, and throw in a few photos for good measure.

I’ll start with some pics – I’ve included a Tele Vue 8mm Plossl for scale. The last one shows the ends of the eyepieces with the Naglers showing their Barlow-type rear elements which are situated close to the barrel ends but allowing (just) enough room to fit standard filters. In case it's not clear from the pics, from left to right it's 8mm Plossl, 5mm Nagler type 6, 7mm Nagler type 1 and 13mm Nagler type 6.

The 7mm Nagler is basically the same design that Tele Vue introduced in 1984 hence they are known as type 1’s. The original ones were smooth sided but later versions acquired rubber grips and eyecups and a safety undercut in the chrome barrel. Optically the design changed little or not at all. Tele Vue kept the 4.8mm and 7mm type 1 Naglers’s on sale even after the type 6 replacement range was launched in acknowledgement of the additional cost of the later range, or so they tell us !. Of course Tele Vue did introduce other Nagler types in between - ie: type 2's, type 4's and type 5's (no type 3's !) but they were not in the shorter focal lengths so the type 6's were the first to supercede the shorter focal length type 1's as far as I know.

As you can see the 7mm type 1 Nagler looks physically slimmer than the type 6’s and has a slightly smaller eye lens. The eye lenses of all the type 6 range are the same diameter I believe. In terms of weight the 7mm weighs the same as the 5mm despite the latters bulkier looks. The 7mm is manufactured in Taiwan (as are a number of Tele Vue’s eyepieces) while the 5mm and 13mm have “Japan” engraved on them. In terms of cost, on the 2nd hand marked the 7mm type 1's tend to cost around 70% as much as the equivilent type 6 - which is why I went for one !.

The eye relief on the 7mm is stated as 10mm whereas the 5mm and 13mm are both 12mm. This makes a little more challenging to see the full field of view in the 7mm however it does have a nice soft rubber eyecup which helps get you eye into the right position. The type 6’s have much thicker an less flexible eyecups so it’s probably just as well that they have a little more eye relief. All are 7 element eyepieces.

The coatings on the outer lenses of the type 6’s seem slightly deeper and darker than the 7mm type 1. When I get some clear skies I’ll be able to compare the sharpness and contrast in astro-use. When looking a terrestrial objects this evening (tree branches at around 100 meters) the views in the 7mm and 5mm looked identical apart from the magnification. The details on a Wood Pigeon perched in the tree were truly impressive through both these eyepieces – I could clearly see it’s iris contracting and expanding as it blinked !.

Last night I had a look at galaxies M81 and M82 in Ursa Major through the 5mm and 13mm type 6’s (the 7mm only arrived today). Both objects were easily framed in the 1.6 degree field of view that the 13mm gives in my Vixen 102mm F6.5 scope but I could not quite squeeze them into the 5mm’s field. The 7mm should frame both galaxies nicely at 95x – can’t wait for clear skies again to see for myself .

John

[tom.yates]

superb eyepieces i have one or two myself

[John]

superb eyepieces i have one or two myself

Which ones Tom ?.

John

[MrEd]

Hi John

I have the 13mm Type 6 and it is my workhorse

eyepiece (i call it my Globuster) . I am never dissapointed when studying DSOs and i do not think

i will ever replace it. A real Gem.

Regards

Ed

[MartinB]

Thanks for that John. I do find it all a bit confusing. What is the difference in terms of performance between the types 1 4 5 and 6. You mentioned eye relief. Do they give different FOVs for a given focal length?

The TV plossls are supposed to be superb, how do you find yours compared with the Naglers?

[John]

Thanks for that John. I do find it all a bit confusing. What is the difference in terms of performance between the types 1 4 5 and 6. You mentioned eye relief. Do they give different FOVs for a given focal length?

The TV plossls are supposed to be superb, how do you find yours compared with the Naglers?

Martin,

On the Naglers, it is confusing but as far as I know all the different versions give an 82 degree field of view except for the latest - the 13mm Ethos which has a whopping 100 degree FoV :shock: - and will have an equally whopping price tag when it comes over here

Each type is a variation on the basic Nagler design basically offering performance enhancements and different focal lengths to it's predecessor. Here is a link to an excellent article setting all this out in more detail:

http://www.cloudynights.com/documents/naglers.pdf

In terms of performance I have only used Type 1 and Type 6 Naglers so I can't comment on the other types however I have never read a negative review of a Nagler (or any TV product for that metter)

On the TV Plossls, they are excellent - IMHO among the very best "standard" eyepieces you can get. In terms of their performance against Naglers, well it's early days as yet but the Plossls provide excellent, sharp, contrasty views across their 50 degree fields which are probably as good as the Naglers that I have tried. Where the Naglers do excel is that, i. the excellent performance extends right across the 82 degree field, even if scopes of relatively short focal length and ii. they eye relief (ER) on the shorter focal length Naglers is longer (and therefore more comfortable) than that of the equivilent Plossl (eg: the 8mm TV Plossl has 6mm of ER while the 7mm Nagler has 10mm). Mind you the TV Radian's offer 20mm ER across their range which is pretty impressive.

I should say that there are other eyepiece makes out there that are as good as the TV ones (eg: Celestron Ultima's, Pentax XW's) but I just seem to like Tele Vue's.

John

[MartinB]

Thanks for that John. Very helpful

[tom.yates]

John, I have the 31,22,12,9 love um all, You are right about the pentax they are very good quality eyepieces i have the 7mm, the 10mm and the 20mm, really crisp views with 70 deg field, I would also reccomend the older smooth side wide field televue's i have the19mm and the 24 these are superb also.

[John]

John, I have the 31,22,12,9 love um all

I had a look at (but not through alas ) a 31mm Nagler last year - it's huge - it's owner referred to is as the "Holy Hand Grenade" !. Strangely I found my hands shaking slightly as I held it - must have been the thought of dropping an eyepiece which would cost nearly £500 to replace !.

John

[MartinB]

Well John, too much temptation. Have just gone and bought a 17mm T4 off Arthur Edwards via UKastro B+S!

[John]

Well John, too much temptation. Have just gone and bought a 17mm T4 off Arthur Edwards via UKastro B+S!

Congrats Martin - I'd like to know what you think of that one - seems to be many folks favourite Nagler on the other side on the pond.

John

[John]

I would also reccomend the older smooth side wide field televue's i have the19mm and the 24 these are superb also.

I agree Tom, I used to own the 15mm, 19mm and 24mm smothie wide fields - they are excellent. A 24mm came up on Astro Buy & Sell recently and I was sorely tempted but ended up getting the 7mm Nagler for about the same money - choices, choices

I also used to have the 7.4mm, 10.5mm, 13mm, 17mm and 21mm smothie TV plossls which are also very good indeed - I think Mike Bacanin has just got hold of a set of these.

Oh dear - I do seem to be addicted to Tele Vue stuff ....

John

[tom.yates]

End of the day mate quality is quality .

[mike bacanin]

Martin, i have the 17t4 and its a stunning sharp eyepiece, i viewed jupiter and although it gave about x119 on my c8 it was razor sharp. i also have the 12 t2 which is a stunner. also the 11t6 . they are all very very sharp on axis.

i was very fortunate to recently acquire a full set of early japan televue smoothside plossls including the 55mm 2 inch, as soon as i get a digital camera i'll post a pic of them. the fl's are 7.4,rare 10.4,13,17,21,26,32,40,55.

btw, i decided to upgrade my HEQ5 with one of the superb berlebach ash tripods, its en route as we speak, should arrive by end of this week. damping time should be virtually zero as they are rock solid ash legs.

regards

mike

[MartinB]

Looking forward to giving the 17mm a whirl Mike. I have a Berlebach tripod for my GPDX and it is superb. The leg adjustment is so smooth with nice scales along the side, rock solid and vibration just isn't an issue. Oozes quality.

[mike bacanin]

thanks for that martin, ever since i saw a berlebach at astrofest a couple of years ago, i hoped to buy one someday!