Equipment Reviews - Page 2

1) Tele Vue 20mm Nagler Type 5 and 22mm Nagler Type 4

2) Tele Vue 27mm Panoptic, 31mm Nagler, and 35mm Panoptic

3) Tele Vue 35mm Panoptic and 41mm Panoptic

4) Oberwerk 11x70mm Binoculars

5) Oberwerk 22x100mm Binoculars

Click here to see page 1 of Equipment Reviews. Click here to see page 3 of Equipment Reviews.


1) Tele Vue 20mm Nagler Type 5 and 22mm Nagler Type 4

The 20mm Nagler Type 5 on the left and 22mm Nagler Type 4 on the right

In the spring of 2003 Al Nagler introduced a newly redesigned 20mm Nagler. The original 20mm Nagler had been introduced in 1985, had 8 elements, and weighed 2.3 lbs. The newly redesigned 20mm has 6 elements and weighs 1.0 lbs.

Although the original 20mm Nagler had been a favorite of deep-sky observers, when the 22mm Nagler Type 4 was introduced many switched over to it. The 22mm Nagler Type 4 at 1.5 lbs. was smaller and lighter than the original 20mm Nagler, and had fewer elements (7 elements). In general the fewer the elements the more likely the light transmission will be better.

A couple of years ago I purchased 22mm Nagler Type 4 and have used it extensively for my deep-sky observations, and one of my observations using this eyepiece is posted on my Visual Observations page.

When Al Nagler introduced the newly redesigned 20mm Nagler Type 5 I decided to buy one and compare it to the 22mm Nagler Type 4. As you may note from the photograph above the 20mm Nagler Type 5 is smaller than the 22mm Nagler Type 4, and also weighs less: the 20mm Nagler Type 5 weighs 1.0 lb., while the 22mm Nagler Type 4 weighs 1.5 lbs. Also, the 20mm Nagler Type 5 has fewer elements (6 elements) than the 22mm Nagler Type 4 (7 elements). The field stop of the 20mm Nagler Type 5 is 27.4 mm, while the field stop of the 22mm Nagler Type 4 is 31.1 mm.

One of the first things I noticed when comparing these eyepieces was that the eye relief was better in the 22mm Nagler Type 4 (19mm) than the 20mm Nagler Type 5 (12mm). If you wear glasses while observing or find a longer eye relief more comfortable this may be something to consider. Also, like all Type 4 Naglers the 22mm Nagler has the "Instajust Eyeguards".

On the other hand the fewer elements in the 20mm Nagler Type 5 had better light transmission which produced brighter images, and the contrast was better. This made it easier to see fainter detail in deep-sky objects in the 20mm Nagler Type 5 than the 22mm Nagler Type 4. While the field of view was similar between them, the longer eye relief in the 22mm Nagler Type 4 seemed to produce more of a "wow" factor than in the 20mm Nagler Type 5, although I found that by getting my eye closer to the eyeguard in the 20mm Nagler Type 5 the field of view seemed the same.

It is possible that the extra element in the Nagler Type 4's provides the longer eye relief, while the fewer elements in Nagler Type 5's better light transmission, which produced brighter images, and the contrast. Depending upon your needs either eyepiece will work for you. They are fairly close in price, $440.00 for the 20mm Nagler Type 5 vs. $460.00 for the 22mm Nagler Type 4 (as of November 2003).


2) Tele Vue 27mm Panoptic, 31mm Nagler, and 35mm Panoptic

The 35mm Panoptic on the left and 31mm Nagler on the right

For a number of years the 35mm and 27mm Panoptics were my favorite low power eyepieces. I kept hearing good things about the 31mm Nagler Type 5 so finally bought one. The 31mm has 6 elements, an 82 degree apparent field of view eye relief of 19, a field stop diameter of 42.0mm*, and weights 2.2 lbs. The 35mm and 27mm Panoptics have also 6 elements, with a 68-degree apparent field of view, and a field stop diameter of 38.7mm and 30.5mm respectively. The eye relief of the 35mm Panoptic is 24mm, and weighs 1.7 lbs., while the eye relief of the 27mm is 19mm, and it weighs 1.1 lbs.

*Note that the actual field of view of an eyepiece is calculated by this formula:

field stop diameter/focal length of the telescope *57.3

On my first night out testing the 31mm Nagler and the 35mm and 27mm Panoptics on deep-sky objects I noticed that the 31mm shows better light throughput and contrast over the Panoptics. For example M42 appeared brighter and with more texture than in the Panoptics, and fainter nebula was visible easier to see as well, as were fainter stars. Also it was sharper out towards the edge of the field of view than the Panoptics, however when used with a telescope that had a f/5 focal ratio the 31mm was not quite sharp to the edge.

Since then I have tested these eyepieces on deep-sky objects and the moon on many nights and found my initial impressions were the same. Here are some of the deep-sky sketches I have made when using these eyepieces, including The Veil Nebula, the California Nebula, as well as visual observations of Barnard's Loop.

I have found there are advantages and disadvantages to both the 31mm Nagler and 35mm or 27mm Panoptics. The 31mm Nagler clearly has the edge in terms of light throughput and contrast over the Panoptics, as well as a wider field of view. However the 31mm costs considerably more (currently $620 as of Feb. 2003) than any of either the 35mm Panoptic ($365) or 27mm Panoptic ($330). Also the 31mm is noticeably larger and heavier than either the 35mm or 27mm Panoptic, and its weight could be a problem when trying to balance a smaller telescope on its mount. As noted in the picture above the 31mm Nagler is considerably larger than the 35mm Panoptic.

The wider field of view can be a mixed blessing when there is a bright star just outside the field of view of the 31mm Nagler. While observing and making a sketch of the North American Nebula I noted that there was a little light scatter from Deneb that reduced contrast slightly, perhaps because of the convex lens element that is located near the bottom of the eyepiece barrel.

In addition the 31mm has shorter eye relief than the 35mm Panoptic, even though it has a wider field of view. So I find it easier to see the entire field of view when using the 35mm Panoptic with its more comfortable eye relief than moving my head around to see the entire field of view with the 31mm. The longer eye relief in the 35mm makes it easier to tuck my eye into the eyecup as well, which helps reducing the effects of local light pollution.

Still, when I am observing deep-sky objects the 31mm is the eyepiece I tend to grab first over the 35mm and 27mm Panoptics, and the one I use most often of the three.


3) 35mm Panoptic and 41mm Panoptic

The 41mm Panoptic on the left and 35mm Panoptic on the right

At an astronomy convention in the spring of 2003 I had the opportunity to try out a new addition to the Panoptic line, the 41mm. The Panoptic 41mm has a 46mm field stop that is supposed to deliver the largest true field possible in a 2" eyepiece. It has also 27mm of eye relief and comes with has an adjustable height eyeguard that can be removed.

In the above photograph you may note that the 41mm Panoptic is not much taller than the 35mm Panoptic but it is wider. It also heavier by about half a pound (the 41mm Panoptic weighs 2.1 lbs. while the 35mm Panoptic weighs 1.6 lbs.). The eye relief is similar between these two Panoptics, 27mm for the 41mm Panoptic and 24mm for the 35mm Panoptic, but the field stop is larger in the 41mm Panoptic (46mm) than the 35mm Panoptic (38.7mm). All of the Panoptics have the same number of elements (6).

On the first night out it was clear early on that the newer glass and better coatings of the 41mm Panoptic gave it an advantage over the 35mm Panoptic: detail in deep-sky objects simply stood out better in the 41mm. On other nights detail on the moon seemed to have higher contrast and were easier to see in the 41mm than the 35mm. The one drawback of the 41mm is its greater price tag, $495.00 vs. $365.00 for the 35mm Panoptic (as of November 2003). The 41mm is however an impressive eyepiece, and one of my favorites for observing deep-sky objects.


4) Oberwerk 11x70mm Binoculars

Side view of the Oberwerk 11x70mm binoculars

A few months ago a pair of 9x63mm binoculars that I had for a number of years were broken. I debated getting them repaired as it would cost more to repair them than they were worth. Then a friend of mine showed me a pair of 8x56mm Oberwerk binoculars he had recently purchased. I was impressed after trying them out as they were lightweight and seemed very good optically, with surprisingly good sharpness, light transmission, and contrast. Plus they were relatively inexpensive. I asked if Oberwerk made larger binoculars in the 70mm range and he said they did. So I decided to check into the 70mm pair to replace my broken 9x63mm pair.

Front view of the Oberwerk 11x70mm binoculars

It turns out that they make two 70mm binoculars, one with magnification choice of 11x and a higher power one of 15x. Both models come with BAK4 prisms, and the optic coatings are broadband multi-coated. The field of view of the 11x model is 4.5, while for the 15x model is 4.3 Exit pupil diameter of the 11x model 6.3 mm while the 15x model 4.6 mm, and the exit pupil distance for the 11x is 23mm while for the 15x is 16mm. Minimum focus distance for both models is 20m and the weight is 3.1 lbs.

I decided to go with the 11x70mm pair rather than the 15x70mm pair as knew there would be times when I would hand hold them and it would be easier to use the lower power pair. For most of my astronomical viewing I use these binoculars on a heavy-duty tripod. The retail price is $179.95, but you can often find them for $149.95. This includes dust caps, neck strap, and a soft carrying case. A hard carrying case would be better for protecting the binoculars.

Oberwerk binoculars have rugged rubber-armored metal bodies, all-glass lenses, right ocular diopter adjustment, and brass 1/4-20 tripod adapter threading. The Oberwerk literature indicates that due to the new low-reflection broadband multicoatings, which has a subtle green color, with faint green and purple reflections, light loss due to reflection and scattering is minimized, providing the highest level of light transmission possible. They suggest also that the view is very close to Fujinon FMT-SX series quality, for a fraction of the price. I didn't have a pair of Fujinon's to test against the Oberwerk's, but was impressed by their performance.

When I tested the binoculars the center focus had a smooth and precise feel to it. The relatively long eye relief made them easy to use, and would be very useful for observers who wear glasses. In addition the rubber eyecups fold down. Detail in the center of the field of view was sharp and contrasty, and was sharp out to between 80% - 85% of the field of view. Considering their size they are relatively easy to hand hold while using them during the day, but for astronomical observing at night a tripod helps to get the most out of them. I would recommend also a heavy-duty "L" adapter for use with a tripod.

Rear view of the Oberwerk 11x70mm binoculars. Note that there is no light cutoff from the prisms.

On the first night I tried them out I was very impressed by their performance. I used them a heavy-duty tripod to steady the view. The limiting magnitude when I was observing was around 5.3. The Orion Nebula M42 was very pretty and showed some nebulosity. The Pleiades also looked very nice, one of the best views I have had of it. It seems to benefit from using two eyes to observe it rather than one eye as we so often do with a telescope. The Andromeda Galaxy M31 filled up most of the 4.5 degree field of view. The Pinwheel Galaxy M33 was easy to see. The open clusters M36, M37, and M38 in Auriga almost fit into the field of view of the binoculars.

Saturn had an oblong shape to it, and Jupiter showed as a disk with a couple of moons nearby. Jupiter was near the Beehive Cluster M44 at this time and the combination of Jupiter, its moons, and the cluster in the background was a neat view. A rising a thin crescent moon rose with earthshine was breathtaking. This was another case where the view seemed to be improved by the use of two eyes. On another night the first quarter moon showed very good detail along the lunar terminator, including a number of craters.

I have used the binoculars since then and each time have been impressed by their performance. They offer far more performance than the price may suggest. The coatings seem to really help bring out detail. For example each of the objects I observed on the first night I have observed many times before with my older pair of 9x63mm binoculars before they were broken. In each case the detail shown in the objects I observed showed up much better in the 11x70mm's than the 9x63mm's, much more than one would expect for simply the difference in magnification and aperture. I believe the coating have a lot to do with the better light transmission and contrast in the 11x70mm Oberwerk's.

So what pair would work best for you? It depends upon your observing needs and style. Since I use my Oberwerk's sometimes during the day without the benefit of a tripod the 11x70mm's were my choice. If you have a heavy-duty tripod and or binocular mount and have a smaller pair of binoculars for daytime use than you may prefer the 15x70mm's. Another consideration is that the 11x70mm's have longer eye relief, important if you wear glasses when observing. Either way I don't think you can go wrong with these binoculars. Highly recommended.


5) Oberwerk 22x100mm Binoculars

Side view of the Oberwerk 22x100mm binoculars

After owning and enjoying my 11x70mm Oberwerk binoculars for a year I wished there was a larger aperture pair available at a reasonable price. By chance when attending an astronomy convention I came across the BigBinoculars.com booth and saw the new 22x100mm Oberwerk binoculars. They looked very nice at and with an introductory price of $395.00 (retail price of $499.95) including case and sliding mounting bar seemed very reasonable. So I ordered a pair.

Front and side view of the Oberwerk 22x100mm binoculars

Like the 11x70mm Oberwerk binoculars the 22x100mm have BAK4 prisms, and the optic coatings are broadband multi-coated. The exit pupil diameter is 4.55mm, and the eye relief is 18mm, which should make them suitable for using when wearing glasses. The field of view is 2.8. Minimum focus distance 25m, and the weight is 8.8 lbs. It comes with a center-focuser and the eyepieces have winged eyecups that help to block stray light. Oberwerk binoculars have rugged rubber-armored metal bodies, all-glass lenses, right ocular diopter adjustment.

When I first compared the 22x100mm's next to my 11x70mm binoculars I realized how much larger the 100mm's are: they are BIG! Also, unlike the 11x70mm's it is not really possible to hand hold the 100mm's. Still with a sturdy mount these binoculars are very impressive performers.

The Oberwerk 22x100mm and 11x70mm binoculars in front of their cases. Note how much larger the 22x100mm binoculars and cases are than the 11x70mm: the 11x70mm are 11" tall and 8.25" wide, while the 22x100mm are 18" tall and 9.5" wide.

On the first night I tested the 22x100mm it wasn't the best night for observing. There was some haze and clouds around, and the limiting magnitude was only around 4.0. However as I was eager to try them out I mounted the binoculars on a heavy-duty wooden tripod and carried them outside. Even though the observing conditions weren't the best I was impressed with their performance.

As with the 11x70mm binoculars the center focus had a smooth and precise feel to it. Detail in the center of the field of view was sharp and contrasty, and was sharp out to between 80% - 85% of the field of view. M22 appeared large and bright and resolved around the edge. M8, The Lagoon Nebula, showed nebulosity on the right hand side of the nebula, the darker lagoon portion in the center, and the star cluster on the left-hand side of the nebula. M17 the Swan Nebula showed its checked marked shape. M11 The Wild Duck Cluster was well resolved.

I decided to bring the 11x70mm binoculars out and compare them with the 22x100mm binoculars side by side. Both were mounted on sturdy tripods. Right away I noticed there was a difference between the binoculars. For example while in the 22x100mm I could easily tell the difference between M8 or M17 and see detail within them, in the 11x70mm while I could tell I was observing a deep-sky objects but not able to distinguish any detail to tell me which was which given the prevailing observing conditions.

Front view of the Oberwerk 22x100mm and 11x70mm binoculars. Note the differences in the size of the objective lenses between the 100mm and 70mm binoculars.

On nights with better transparency (limiting magnitude of 5.0 to 5.4) I was able to resolve more detail in deep-sky objects. Here is a list of some of the deep-sky objects I have observed with the 22x100mm binoculars, as well as the moon, planets, and comets:

The Double Cluster (NGC 869, magnitude 5.3, and NGC 884, magnitude 6.1) were beautiful and well resolved showing some red colored stars.

M1 (NGC 1952, magnitude 8.4) - The Crab Nebula, a supernova remnant located in Taurus. Both the Crab Nebula and zeta Tauri easily fit into the same field of view, with the nebula appearing relatively large and having a grey color to it.

M2 (NGC 7089, magnitude 6.6) - Globular cluster located in Aquarius. This cluster appeared large and bright, and the outer portion of the cluster was resolved.

M4 (NGC 6121, magnitude 5.4) - A very pretty globular cluster in Scorpius. The outer portion of the cluster was resolved in the binoculars, with the line of about dozen 10th to 12th magnitude stars running north to south give the center of the cluster a linear appearance to it.

M6 (NGC 6405, magnitude 4.2) - Open cluster in Scorpius is resolved in the binoculars with a bright orange/yellow star in the middle and a pretty butterfly shape to it.

M7 (NGC 6475, magnitude 3.3) - This open cluster is located in Scorpius and appeared loosely compressed, large and bright with an irregular shape.

M8 (NGC 6523, magnitude 4.6) - The Lagoon Nebula, a nebula and cluster located in Sagittarius. The nebula on the right hand showed some variation in tone, being brighter at the bottom and dimmer at the top. The star cluster was prominent on the left-hand side, with the lagoon shape in the middle very noticeable.

M11 (NGC 6705, magnitude 5.8) - The Wild Duck Cluster is located in Scutum. This open cluster is nicely resolved in the binoculars with a bright star noted near the center.

M13 (NGC 6205, magnitude 5.8) - The Great Cluster of Hercules, appeared very large and bright, and I could resolve the cluster around its edges and began to resolve it across its core. It appeared very pretty as always.

M15 (NGC 7078, magnitude 6.3) - Sometimes referred to as the Great Pegasus cluster. As with M2, this cluster appeared large and bright, and the outer portion of the cluster was resolved.

M16 (NGC 6611, magnitude 6.0) - The Eagle Nebula, an open cluster and emission nebula located in Serpens. Appeared very large with both the nebula and cluster resolved. Through the binoculars it lived up to its name, with the bird shape to the nebula prominent.

M17 (NGC 6618, magnitude 6.0) - The Swan Nebula is composed emission nebula and open cluster located in Sagittarius. Through the binoculars the swan shape to the nebula was noticeable and showed some variation in tone.

M18 (NGC 6613, magnitude 6.9) - A small open cluster located in Sagittarius. It was nicely resolved in the binoculars.

M19 (NGC 6273, magnitude 6.8) - A globular cluster located in Ophiuchus. I was not able to resolve the cluster in the binoculars.

M20 (NGC 6514, magnitude 6.3) The Trifid Nebula, which is a nebula and cluster located in Sagittarius. Both the northern and southern portions of the nebula were visible, with the southern portion larger and brighter than the northern one. In the southern portion the double star was visible, as were the dark rifts that give the nebula its name. In the northern portion of the orange or red colored star was prominent.

M21 (NGC 6631, magnitude 5.9) - This open cluster is located in Sagittarius. A small but pretty cluster and resolved in the binoculars.

M22 (NGC 6656, magnitude 5.2) - This globular cluster is sometimes referred to as the Great Sagittarius Cluster. Like M13 it appeared large, bright and very pretty, and I could resolve the cluster around its edges and began to resolve it across its core.

M24 - The Small Sagittarius Star Cloud (magnitude 4.6) is well suited to observing with binoculars as it has a large diameter of 1 degree by 2 degree, which includes also the open cluster NGC 6603 (magnitude 5.9). The star cloud is a dense part of our Milky Way galaxy. M24 is well resolved through the binoculars, with numerous brighter and dimmer stars visible, as well as areas of darker nebulosity that run through it.

M25 (IC 4725, magnitude 4.6) - A pretty open cluster located in Sagittarius. Nicely resolved in the binoculars, with many small stars located near the top of the cluster.

M27 (NGC 6853, magnitude 7.3) - The Dumbbell Nebula, a planetary nebula located in Vulpecula. Through the binoculars I could easily make out the central dumbbell portion of the nebula, as well as the fainter portions on each side that gives it the football shape. There was a light green color to the nebula, and due to the binocular vision it almost appeared 3-D and floating in a sea of background stars.

M28 (NGC 6626, magnitude 6.9) - This globular cluster is located in Sagittarius. I could resolve the cluster around its edges.

M30 (NGC 7099, magnitude 6.9) - This globular cluster located is in Capricornus. I was not able to resolve this cluster through the binoculars.

M31 (NGC 224, magnitude 3.4) - Also known as the Andromeda Galaxy. With averted vision there appeared to be dark lanes on one side of M31. Also the central core of M31 appeared star like and the central region brighter than the outer arms. Both M32 (NGC 221, a dwarf elliptical galaxy with a magnitude of 8.2) and M110 (NGC 205, an elliptical galaxy with a magnitude of magnitude 8.0) were visible nearby.

M33 (NGC 598, magnitude 5.7) - The Triangulum or Pinwheel Galaxy appeared large, diffuse and elongated in shape, with a brighter central region.

Open clusters M36 (NGC 1960, magnitude 6.0), M37 (NGC 2099, magnitude 5.6), and M38 (NGC 1912, magnitude 6.4) in Auriga were resolved to the core and very pretty.

M41 (NGC 2287, magnitude 4.5) - An open cluster located in Canis Major. Appeared very pretty and easily resolved, with the main part of the cluster having an almost square shape to it. There is also a prominent red star near the center of the cluster.

M42 (NGC 1976, magnitude 3.7) - The Great Orion Nebula was large and well defined showing lighter and darker mottling within it as well as a light blue color. The brighter inner portion of the nebula was noticeable, and fainter nebula that extending out from it on both sides and towards the top of the nebula. The curved "bat wings" were visible along the bottom of the nebula, with M43 (NGC 1982, magnitude 6.8) visible below it. The Trapezium was resolved into four stars, and there were times when the fifth and sixth stars would pop into view. Several smaller stars were visible embedded in the nebula on one side.

M45 (magnitude 1.5) - The Pleiades or Seven Sisters was beautiful, with the color of the two small central orange and blue stars pronounced, while the brighter stars in the cluster providing almost a 3-D look to it.

M57 (NGC 6720, magnitude 8.8) - The Ring Nebula, a planetary nebula located in Lyra. In the binoculars it was resolved and surprisingly bright, and I could almost make out the lighter interior of the ring.

M78 (NGC 2068, magnitude 8.8) - bright nebula located in Orion. The nebula appeared comet-shaped with two stars visible in it.

Open clusters M103 (NGC 581, magnitude 7.4) and NGC 663 (magnitude 7.1) in Cassiopeia were pretty and resolved in the binoculars.

Alberio - Double star, Beta Cygni, located in Cygnus. It was resolved into its very pretty blue and golden-yellow colors and was beautiful as always to observe.

Mizar - was resolved into its four stellar components.

I observed the moon on a number of occasions and was impressed in the amount of detail visible in the binoculars. For example at crescent phase the earth lit portion of the moon as well as the mare were well defined, with many craters on the sunlit portion visible. At first quarter phase small craters were visible on the lunar mare, as well as detail within larger craters. During a total lunar eclipse the binoculars provided some nice views because using two eyes gave almost a 3-D effect where the moon appeared to be floating against a backdrop of stars. For a while the moon was located below several stars that formed a triangle that reminded me of the shape of a roof of a house, and it was as if the eclipsed moon was moving through a house of stars. The colors ranged from red/deep coppery orange along the northern portion of the moon, coppery orange along the middle, orange yellow near the middle bottom, and white near the southern portion of the moon. Here is a photo I took of the eclipsed moon through a telescope.

I used the Oberwerk 11x70mm and 22x100mm binoculars to observe the occultation of Jupiter by the moon on November 9th, 2004.

Observing the sun with filers made from Baader white light solar material showed very fine detail within sunspots, including the umbra and penumbra. In addition facula and granulation's were noted on the suns' surface.

I observed Mercury one morning while it was low in the eastern sky using the 22x100mm binoculars. Even though the seeing wasn't very good I was able to see Mercury's gibbous phase, and the planet had somewhat of a reddish orange color to it. However this may have been due to the low elevation of the planet.

On another morning the gibbous phase of Venus was sharply resolved.

During the 2003 opposition of Mars it often appeared as a disk. There were times when I could make out the South Polar Cap as well see some faint surface detail.

Jupiter was resolved as a disk as well and there were times when there appeared to be some cloud detail visible including the North Equatorial Belt, South Equatorial Belt, and the northern and southern polar regions. The four Jovian moons were easily visible.

Saturn appeared elongated and could almost make out the separation between the globe and the rings. Titan was visible nearby as were Tethys, Dione, and Rhea.

When two recent comets graced out skies the 22x100mm binoculars did a great job in bringing out fine detail in Comet Bradfield (C/2004 F4) in April 2004 and Comet NEAT (C/2001 Q4) in May 2004. Comet Pojmanski (C/2006 A1) showed nice detail through the binoculars as well.

Rear view of the Oberwerk 22x100mm binoculars. Note that there is no light cutoff from the prisms.

The Oberwerk 22x100 binoculars offer very impressive performance at a very reasonable price. They often seem to perform as well as a telescope with a similar aperture at low power because of using two eyes, and I sometimes just take them out to observe rather than taking out a telescope. Highly recommended.


Articles 2000 - 2015, Eric Jamison, All rights reserved.

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