Review - TeleVue Nagler Eyepieces

The TeleVue Nagler eyepiece line is an industry standard in the field of astronomy [Image Credit: TeleVue].

Introduction

I was working part-time at a bank when I purchased my first serious telescope and mount in 1997 - a Takahashi FS-78 and a Vixen Great Polaris. Back then, I could only afford more economical eyepiece designs that were available from Orion and TeleVue [first Plossls, then Wide-Fields]. While providing satisfying contrast and clarity, I realized there were significant limitations in what I could see with 50° or 65° apparent fields of view.

It had always been a goal of mine to save up and move my collection toward an all Nagler one; but to be honest, many of the Type 1 and Type 2 eyepieces were bulkier and heavier than I wanted to handle. Eventually, TeleVue released the Type 4 and Type 5 lines, which were generally smaller and lighter than the models they replaced [the exception being the 31mm Type 5 ], and so I finally took the plunge into true wide-field observing.

Twenty-five years since their introduction, only one of the Type 4's [the 22mm] and two of the Type 5's [the 31mm and 16mm] are still being manufactured, the others having been supplanted by the newer Ethos line.

Eyepieces

TeleVue Nagler 31mm Type 5:

Focal Length:  31mm

Apparent Field of View:  82°

Eye Relief:  19mm

Field Stop:  42mm

Weight:  2.2 lb [1.0 kg]

Review:

It's amazing what you'll do to justify spending almost $700 on one eyepiece.  I went to a store in Dallas some time ago to size up the 31mm, and was surprised at how 35mm Panopticish it felt; from the eye-relief [it's actually a little bit less], to the weight, to the bulky size - and of course I had to have it.  So now I've come up with a "buy and hold" strategy when it comes to high priced astro-equipment - buy the best now, and hold it forever, or at least until the next upgrade model is available; this way, I don't skimp on observing gratification, but do replace my previous "buy and sell to buy something better that's already available" strategy, which only costs more in the long run.

I'm very pleased that the 31mm works so well with the FCT-76; stars are flat to the edge, much more so than I'd anticipated. Since my Tak takes only 487mm to come to focus, the largest star clusters come into play like The Pleiades - M 45, Alpha Persei Moving Group - Mel 20, Hyades - Mel 25, and Coma Berenices Star Cluster - Mel 111 [mostly].  The Small Sagittarius Star Cloud - M 24, Scutum Star Cloud, and Cygnus Star Clouds made for some great viewing under Fort Davis' dark-skies, so many stars you never realized were there. I'm also looking forward to scrutinizing southern objects like the Large & Small Magellanic Clouds with this eyepiece when I go to Australia / New Zealand in a couple of years.  Wide-field observing has never been better.  Start saving your money now!

Priced ~ $734 USD.

TeleVue Nagler 22mm Type 4:

Focal Length:  22mm

Apparent Field of View:  82°

Eye Relief:  19mm

Field Stop:  31.1mm

Weight:  1.5 lb [0.68 kg]

Review:  

This was my first eyepiece of the Nagler 4 series.  The 22mm beautifully compliments a high-quality telescope by showing stars as colorful points over a flat field [faster scopes may stretch edge stars out a bit].  Eye relief is very nice, as well as the diameter of the glass which makes wide views easier [on the older Nagler series, you have to put your eye closer to the eyepiece to get that "space walk" effect].  Although I could probably get away with having the 31mm, 17mm, and 9mm as a deluxe eyepiece set, I plan on keeping the 22mm because every object has a specific magnification and fov that brings out its best.  

For instance, and this is being picky, Collinder 69, the cluster that makes up the head of Orion, looks best through this eyepiece when I'm using the FCT-76.  I've tried to like it better through the 17mm, but it's just not the same. Other objects like Cr 70 - Orion's Sword, Cr 132 / 140 under Canis Major, M 44, and M 7 all subjectively fit to perfection in the 22mm.  Every telescope has a different focal length, so try several eyepieces on your favorite objects and then decide which to keep.

Priced ~ $512 USD.

TeleVue Nagler 17mm Type 4:

Focal Length:  17mm

Apparent Field of View:  82°

Eye Relief:  17mm

Field Stop:  24.3 mm

Weight:  1.6 lb [0.73 kg]

Review:  

This is probably my favorite wide-field eyepiece because you can get away with using it on almost any object.  Open clusters really shine through the Tak using the 17mm, especially NGC 869 / 884, M 35 / NGC 2158, M 46 / M 47, NGC 2477 / 2451, and NGC 6633.  The eye relief is a bit shorter than the 22mm, but is still very comfortable.  If you're on a tight budget, consider splitting focal lengths between the Nagler 22mm and 12mm Type 4's and buy this one.

Priced ~ $475 USD.

TeleVue Nagler 16mm Type 5:

Focal Length:  16mm

Apparent Field of View:  82°

Eye Relief:  10mm

Field Stop:  22.1mm

Weight:  0.44 lb [0.20 kg]

Review:

I bought a pair of 16mm Naglers to test out and use exclusively with my Baader Planetarium MaxBright II Binoviewer. Some of the considerations you should weigh when picking an eyepiece for this observing platform are eye relief, apparent field of view [apov], weight and bulk, and price.

Compared to other Type 4's and 5's, which have 17mm-19mm of eye relief, the 10mm of the Nagler 16mm is a bit tight through a binoviewer and impossible if you wear glasses. I find that I can make it work even with inadvertant contact of eyelashes to glass. So if you go this route, be prepared to clean them on a fairly regular basis.

It's also difficult to see the entire 82° apov, as there is a natural limit to how much can be viewed when both eyes must remain centered to merge the images from two eyepieces [when monoviewing, this isn't an issue]. The effect being that the outer viewing area has a practical field stop far smaller than the design allows. That isn't necessarily a bad thing - but it is noticeable. When looking through the eyepiece in binoviewer mode, the edge of the field is "blurry." The TeleVue DeLite 18.2mm by comparison has a discrete circular field stop; which, in my opinion, makes for more pleasant or "relaxed" observing.

Both the weight and bulk of the 16mm are excellent and never impede use through the MaxBright II. In fact, the tapered top of the eyepiece is well suited for use with binoviewers in that my nose never comes in contact with either, something that does happen regularly with the DeLite series but not with the Panoptic series.

So who should buy this eyepiece and how can it be used to its fullest potential?

If you don't wear eyeglasses and aren't using a binoviewer, this is a great little 1.25" eyepiece. The views are as sharp as the other mid-focal length Naglers but without the bulk. And when you use the 16mm with a high quality barlow like the Baader Planetarium 1.25" 2x Carl Zeiss Abbe Barlow, you convert the eyepiece into a 6.5mm Nagler Type 5.

If you wear eyeglasses and plan to use a binoviewer, there are better options to choose from - namely, the DeLite 18.2mm.

Priced ~ $388 USD.

TeleVue Nagler 12mm Type 4:

Focal Length:  12mm

Apparent Field of View:  82°

Eye Relief:  17mm

Field Stop:  17.1mm

Weight:  1.0 lb [0.45 kg]

Review:

The Nagler 12mm Type 4 is one of my favorite hybrid 1.25"/ 2"eyepieces. Although you can use it as a straight 2", the focal point is longer than the 22mm and 17mm, and requires either additional back focus or an adapter at the diagonal to lengthen things out. I've added a Baader Planetarium 2" to 1.25" Clicklock Reducer to create that extra distance.

Priced ~ $425 USD.

TeleVue Nagler 9mm Type 6:

Focal Length:  9mm

Apparent Field of View:  82°

Eye Relief:  12mm

Field Stop:  12.4mm

Weight:  0.4 lb [0.19 kg]

Review:  

I wanted to hold out on buying this one hoping Al would come up with a Nagler 9mm Type 4, but a trip to Prude Ranch required a medium power eyepiece. The 9mm has been updated to match the streamlined design of the other Nagler Type 6's, with shorter eye relief when compared to the Nagler Type 4's [not too short though], smaller glass diameter on top, non-Instadjust [which I prefer on the first generation design, the movement on the Instadjust can be easily forgotten when observing in the early morning hours], and sharp all the way across the fov. Contrast is also higher than I expected [I sold my Radian 8mm even though it was a little sharper because of the smaller 60° apparent fov compared to the Nagler 9mm's 82° apparent fov]. It replaces the Nagler 9mm Type 1 which was bulky for its focal length, so binoviewing is definitely in the cards here.

Priced ~ $354 USD.