Equipment Reviews - Page 7

1) Tele Vue 13mm Ethos Eyepiece

2) Astro-Physics 800 Equatorial Mount

3) Tele Vue 17mm, 10mm, 8mm, 6mm, and 3.7mm SX Ethos Eyepieces

4) Tele Vue 17mm.3mm Delos Eyepiece

5) The Original Bug Shirt

6) Binocular Viewers

7) Tele Vue (TV) 18mm and 7mm Delite Eyepieces

Click here to see page 7 of Equipment Reviews.

1) Initial Impressions of the Tele Vue (TV) 18mm and 7mm Delites Eyepieces.

I recently had the opportunity to try out the new TV 18mm and 7mm Delight eyepieces to see how they compared to the TV 24mm Panoptic. I have used the TV 24mm Panoptic in my binocular Binocular Viewers for many years and it has been one of my favorite eyepieces to use.

When the eyepieces arrived I took them out of the boxes and compared them with the TV 24mm Panoptics. One of the first things I noted was how dark the coatings were on the Delights Vs the Pans: the coatings on the Delights seemed black compared to the light green coatings on the Pans.

In addition, I did some daylight testing of the Delights vs the Pans using a TV and found that the Delights showed more detail and provided shaper images, and lighter than the Pans. The same was true when I tested them on objects in the nighttime sky including the planets and deep sky objects, as well he Moon using a TV mm apo refractor. Highly recommended.

2) Astro-Physics 800 Equatorial Mount

Side view of the AP800 mount showing the equatorial head, counterweights, pier, legs and tension rods.

My first experience with Astro-Physics (AP) was in 1983 when I was looking for a dual-axis drive corrector for my C8 for doing deep-sky astrophotograhy. A friend of mine owned one for his C11 and it worked well so I ordered one. It allowed me to make fine corrections during long exposure astrophotographs.

In 1984 I noticed in Sky and Telescope magazine that AP was offering apochromatic refractors. I called AP and talked to Roland about the telescopes. Back then when you called AP he usually answered the telephone. He indicated that he had 7” f/15 and 8” f/15 lenses available that used the NASA glass. He was asking around $2500 for the 7" and around $3500 for the 8". I could not afford them, so ordered a 4" f/6.

These early AP 4" f/6 and 5" f/6 telescopes did have some secondary spectrum on bright objects, but I was very impressed by the wide, sharp and high contrast views they provided. This helped to enhance low contrast planetary features, and lunar features seemed to have more relief to them producing a "3D" look. Also the telescope performed quite well at low power offering a wide field of view (FOV) for observing deep-sky objects (DSO) and comets.

In 1986 I bought a 6" f/9 refractor from AP, and finally found a telescope that showed me more detail on the planets then any of my earlier telescopes did. M-42 was a mass of very fine mottling, and it appeared more of a bluish color to my eye then the usual green I had seen in other telescopes. One night with very dark and steady skies the bottom of the nebula had a reddish color to it.

Using these two telescopes I came to appreciate the optical quality and portability of apochromatic refractors, and decided that they would work well for my observing needs, which includes lunar and planetary, deep-sky, comets, and double stars. Hence I have owned apochromatic refractors since then, first from AP and more recently from TMB.

However, unlike the fork mounted C8 that I owned which was portable and easy to set up, larger apochromatic refractors require substantial mounts. I learned early on that the less portable a telescope was to carry around and set up the less likely I would use it. So in the mid-1990's I built Dobsonian-style mounts for my refractors. Most of the Astronomical Sketches and Visual Observations on my web page were made using Dobsonian-style mounts and alt-az mounts.

Still, there are times that having an equatorial mount with tracking can have its advantages, such as when doing astrophotograhy or observing at high magnifications. Over the years I have owned a different equatorial mounts for my apo refractors, including a Byers 58 equatorial mount and an AP 706 equatorial mount. In 2003 I purchased an AP 800 equatorial mount from the late Thomas Back. He bought this mount in 1988. It is my understanding from talking to the folks at AP that mounts of this age will not accept encoders for digital setting circles. However newer 800 mounts should.

Close up view of the equatorial head, counterweights, and pier.

One of the things I like about the 800 mount is that it disassembles into manageable pieces that aren't too heavy or bulky to carry. The weight of the equatorial head and counterweight shaft is 45 lbs. The counterweight shaft can be removed from the head to make it easier to carry. The 56" pier weighs 36 lbs., while the weight of each leg is 8 lbs.

Close up view of the drive corrector

The drive corrector allows the user to set different tracking rates, as well as make corrections.


Overall I find that mount worked quite well with the AP 180mm f/9 EDT apochromatic refractor, and now with the TMB 175mm f/8. It is very stable and when focusing the telescope vibrations settle quickly. These days most people look for GOTO mounts, but if you’re looking for a strong workhorse mount for your large refractor this may be the ticket. Highly recommended.

3)Initial Impressions of the Tele Vue Ethos 17mm, 10mm, 8mm, 6mm, and 3.7mm SX Eyepieces

TV 20mm Nagler, Ethos 17mm, 10mm, and 3.7mm SX Eyepieces

I recently had the opportunity to try out some of the Ethos eyepieces including the 17mm, 10mm, 8mm, 6mm, and 3.7mm SX. The above photo shows some of the eyepieces along with a TV 20mm Type 5 Nagler for comparison. The 17mm, 10mm, 8mm, 6mm have a 100 apparent degree field of view (FOV), while the 3.7mm SX has 110 apparent degree FOV.

One of the first things that struck me was how tall the 17mm Ethos and 3.7mm Ethos SX are. The 17mm is around 4.5" tall, while the 3.7mm is around 5". Depending upon the eyepiece case that you use these eyepieces may need to be stored lying down rather than standing up. Also both eyepieces contain a lot of glass (as does the 21mm), so like telescope optics, these eyepieces could take some time to adjust to differences between inside and outside air temperature, such as going from a warm house to a cold winter night.

The 17mm is larger than the other Tele Vue Naglers and Panoptics around the 20mm range that I have used in the past.

I have used the TV 20mm Type 5 Nagler for over eight years and it has been one of my favorite eyepieces. So I was curious how it would compare with the 17mm Ethos. When I examined them inside under a bright light I noted that both the Nagler and the Ethos had dark green coatings on the eye lens. On the Ethos the field lens also had dark green coatings, while the Nagler did not. This may be one reason why the 17mm Ethos seemed to show a brighter image than the 20mm Nagler.

The telescopes I used included my TMB 105mm f/6.2 and TMB 130mm f/9.25 that were mounted on alt-az mounts. The difference in magnification between the 20mm Type 5 Nagler and the 17mm Ethos in the TMB 105mm f/6.2 was only 6x. In the TMB 130mm f/9.25 the differences between these eyepieces was higher, 11x.

On the first night with the TMB 105mm when observing M42 the Orion Nebula the 17mm Ethos appeared sharp pretty much to the edge of the FOV. Comparing it with the 20mm Nagler the 17mm Ethos showed a noticeably wider FOV when I moved my eye around, and seemed to show a brighter image, as well as higher sharpness and contrast. There appeared to be more subtle detail visible using the 17mm Ethos. The blue color of the central area of M42 was more prominent in the 17mm as well.

In the 10mm, 8mm, and 6mm Ethos M42 showed fine detail in the central region, and the outer region was prominent as well.

M45, the Pleiades, in both the 20mm Nagler and 17mm Ethos looked pretty, easily fitting into the FOV. However the wider FOV of the Ethos provided a more pleasing view.

In Taurus the color of Aldebaran was more pronounced in the 17mm.

M8, M17, M20, M22, and Comet C/2009 P1 Garradd appeared brighter and showed more subtle detail in the TMB 105mm with the 17mm Ethos than in the 20mm Nagler.

Using the 20mm Nagler and 17mm Ethos observing Jupiter the belts appeared more pronounced in the 17mm, even though this is relatively low power for the planet.

In the TMB 105mm and the TMB 130mm the Moon in the Ethos 17mm, 10mm, 8mm, and 6mm showed nice detail, and the wide FOV was impressive.

In the TMB 130mm M65, M66, and NGC 3628 appeared brighter in the 17mm Ethos, however I needed to role my eye around to see all of them.

The only Ethos eyepiece that did not seem to work as well for me was the 3.7mm SX 110 degree FOV. For me the eye relief did not seem as much as in the other Ethos. Also I have floaters in my eyes and they seemed to be more noticeable and distracting in the 3.7mm, unlike the other Ethos. In large objects like M42 and M45 I could only see the central portions. The Moon a few days from first quarter phase was impressive, but once again the eye relief did not feel comfortable.


These eyepieces are impressive performers and I would highly recommended them. However, as they cost more than the Naglers and other 80+ degree eyepieces, some people have asked if they are worth it. I think it depends upon your observing interests. For me, after using the Ethos, I can understand why some people may feel that these are the only eyepieces they need for their telescopes, in particular if they are avid deep-sky observers.

However I know some observers who do not like to move their eye around to see the entire FOV, so prefer Naglers or other brands that offer other 80+ degree eyepieces instead. In addition the Naglers are smaller in size and weight, and cost less. So it really comes down to personnel preference.

4) Initial Impressions of the Tele Vue (TV) 17.3mm Delos Eyepiece

TV 17.3mm Delos Eyepiece

Recently I had the opportunity to try out the new TV 17.3mm Delos eyepiece. I was interested to see how it compared to my Tele Vue 20mm Type 5 Nagler that I have used for a number of years and is one of my favorite all time eyepieces.

First I compared the Nagler 20mm type 5 with the 17.3mm Delos in the house under a bright light. It appeared that the Delos had darker coatings on the eye lens and field lens than the Nagler. Also the eye lens was noticeably larger in the Delos (35mm or 1.4") than the Nagler. The sliding eye guide is a nice feature in the Delos as well.

The 17.3mm Delos, and indeed the entire Delos eyepiece line, all have an eye relief of 20mm. By comparison the 20mm Nagler Type 5 has an eye relief of 12mm.

I set up my TMB 105mm f/6.2 on its alt-az mount for the comparison. The difference in magnification between the 20mm Nagler (31x) and 17.3mm Delos (36x) is small, only 5x.

First up was the Moon, which was four days from full phase. At first I did not note much of a difference. However after comparing them again I felt that the Delos showed a little more detail.

Next I swung the scope over to the Pleiades Star Cluster, M45. As with the Moon at first I did not note much of a difference. However I later noted that the orange and blue star near the center of the cluster was easier to see in the Delos.

Jupiter was next and I was surprised as I thought that the performance of the two eyepices would be similar as they had been for the Moon and M45. However the Delos seemed to show more detail than the Nagler. For example the contrast seemed to be higher in the Delos so it was easier to see the belts and zones on Jupiter. Jupiter and the Jovian moons were better defined as well.

Looking to the east I saw that Orion was just rising, so I swung the scope over to observe M42. It was still quite low, but the detail was easier to see in the Delos than in the Nagler.

The darker coating on the eye lens and field lens in the Delos may help to explain why more detail was visible in M42 and on Jupiter. This may also be why some observers have suggested that these eyepieces work well for the planets.

The other thing that I noticed was that with the larger eye lens in the Delos you do get the impression of looking out of a window rather that through an eyepiece. It is an interesting observing experience, and not one I have noticed in Naglers, Ethos, or Panoptics.

It looks like TV has another winner on its hands. Highly recommended.

5)The Original Bug Shirt

One of the problems of observing when mosquitoes are out is that not only are they distracting but depending upon where you live they can also carry diseases such as West Nile Virus and Eastern Equine Encephalitis (EEE) that could cause health issues.

In addition depending upon where you live mosquitoes can be out from the spring through the fall when many deep-sky objects well placed for observing.

Over the years I have tried a variety of ways to try and reduce the number of mosquitoes bites. This includes wearing long pants tucked into boots, a long sleeve shirt, and a hat, as well as mosquito repellant. This helped but they still managed to bite, sometimes through my long pants and shirt.

In addition wearing long pants and a long sleeve shirt on warm humid nights caused me to perspire more.

Then I heard of The Original Bug Shirt and pants. It is designed to protect against biting insects. It uses lightweight but extremely densely fabric that prevents mosquitoes bites yet lets air through.

The same holds true for the hood and face screen. For example while seated at the eyepiece I can roll the face screen down enough to provide protection but also observe using binoculars, a telescope with 2" and 1.25" eyepieces, or a binocular viewer. I usually wear a baseball cap under the hood which allows the hood to rest just above the binoculars, eyepieces or binocular viewer

I ordered one and it has significantly cut down on mosquitoes bites by providing virtually head to toe protection. In addition it is made of lightweight material that makes it comfortable to wear even on warm humid nights.

When wearing the Bug Shirt and pants I usually only need to apply mosquito repellant to the back of my hands. It is one of the best investments I have made in my astronomy gear. Highly recommended.

Here is a link to their webpage:

6) Binocular Viewers

Badder Binoviewer

Some years ago I read an article in S&T regarding the advantages of using two eyes when observing. It indicated that we are wired for binocular vision.

Because of this the brain is more likely to believe what it is seeing if it is getting input from both eyes.

This is particularly helpful when trying to see and sketch fleeting planetary detail, but it is helpful for other observing as well.

My first experience with a binocular viewer (BV) was in the 1990's when I purchased one. It turned out to be a .965 binocular head from a microscope, and it did not seem to offer much of an improvement over a 1.25" eyepiece I was using for observing. I did not find it very useful and sold it.

Later I got an email from a good friend of mine Thomas M. Back who had tried a Badder BV and found it worked very well for him. I tried it and found the same thing, so I bought one also.

Since then I use the Badder BV often when I observe the Moon and planets.

I have heard from other observers who have used BV's from other manufactures and like them.

Using a BV when observing the Moon makes it easier to see the detail, and for lack of a better word it seems more "real".

I use it sometimes when I observe deep sky objects as well. For example observing brighter DSO's like the Orion Nebula in a BV using a pair of 24mm Panoptics really brings out more detail.

Using two eyes when observing reduces the impact of floaters as well.

It can also reduce eye strain.


Using a binocular viewer can add a new dimension to your observing. The main disadvantage is the cost of the BV and two sets of eyepieces.

If you are not sure it will work for you see if you can you can try one out at a star party, or buy one from a store that allows you to return it it does not. Highly recommended.

Articles © 2000 - 2016, Eric Jamison, All rights reserved.