EYEPIECES


Tele Vue Panoptics and Radians, along with filters and a Williams diagonal on observing table.
Eyepieces are the most important accessory you will need when it comes to visual viewing. There are so many available however, that choosing which ones to buy can be a difficult task. Good ones are not cheap, and even then you need eyepieces that will give you the desired magnifications with the telescope you are using. It becomes a lot worse if you own more than one telescope, especially when they vary in focal lengths like mine do. I bought my eyepieces in 2002-2003, and at that time the 2 leading manufacturers as far as I knew were Tele Vue and Pentax. There were not as many other companies making premium quality, wide field eyepieces back then. I purchased my 6" F/8 achromat on the EQ6 at this time, as I wasn't quite sure what to get. I wanted a large reflector for deep space viewing, and was also considering buying an apo refractor or an F/15 achromat for planetary use. I didn't know much about telescopes at the time, so I basically bought the 6" refractor to give me time to think about it.

I wanted to get good eyepieces, as this was no entry level telescope I was dealing with. I also knew that I would probably be buying at least one more telescope, and I would want enough eyepieces to cover the capabilities of anything I might add to my collection. I wanted a wider field of view than the standard 50° most normal plossl's give you. I also wanted good eye relief- something that is difficult to get on a high power eyepiece with a wide field. I never was a fan of having to almost literally touch the eyepiece with my eyeball to see into an eyepiece. I know that my vision will probably start to go eventually as I age, and I want to be able to use my telescopes as long as possible.

LOW/MID MAGNIFICATION


Tele Vue Panoptics:41mm, 35mm, 27mm, 24mm, 22mm, 19mm, and 15mm.
I chose the Tele Vue Panoptic series for the combination of their larger field of view, clean sharp images, and the good eye relief. Televue Naglers and some Pentax eyepieces had a wider field of view (82°), but they were quite expensive compared to the Panoptics, which I might add are not cheap to begin with. The Panoptics have a 68° field of view, and the one with the lowest eye relief is the 15mm, which I believe has 13mm eye relief.

The view of the Andromeda Galaxy and it's companion galaxies from a dark sky is stunning through my 10" Newtonian with the 35mm Panoptic. For low power/ wide field viewing, the view through a good 2" eyepiece is breathtaking compared to a 1.25" eyepiece. The 27mm Panoptic is also good in this aspect, but generally I only use the 41mm in my Refractor. I use some of the others for viewing larger Nebulae, and certain galaxies, as well as wide field views of the Moon. I sometimes use the 41mm in my 4" shorttube refractor as a substitute for my 25x100 binoculars until I get a mount for them.

MID/HIGH MAGNIFICATION


Tele Vue Radians:12mm, 10mm, 8mm, 6mm, 5mm, and 4mm.
One problem that I found with almost every high power eyepiece that I looked into at this time was that the shorter the focal length, the lower the eye relief. Like I said, I don't like having to almost touch the eyepiece with my eye to see the entire field of view, and it will get harder to do as my eyes get older. I know that a wide field of view isn't exactly cricial for most of the planetary viewing I would be doing, but still it's nice to have as large a background as possible when looking at something like the Ring Nebula.

I chose the Tele Vue Radian series. I have all of them except for anything above the 12mm, as that is getting into Panoptic territory. They all have a 60° field of view, which is less than Panoptics and Naglers, but still better than 50°. They not only give clean sharp views, but they have 2 features that most, if not any other eyepiece doesn't offer together.

One of these features is the adjustable eyeguards. The sliding cone around the edge of the eyepiece viewing end is about 2" in diameter, and is coated with rubber on the top. This allows you to slide it up so you can use it to block outside glare while you look into it. For people with glasses, you can lower the eyeguard to accommodate proper eye relief, and the rubber keeps most normal eyeglasses from touching the eyepiece and possibly scratching it. The other feature is the actual eye relief itself. Every Radian eyepiece has an eye relief of 20mm. Somehow through the marvels of engineering and design the eye relief on my 12mm is the same as that of my 3mm. This makes it much easier to find the "sweet spot" with your eyeball than other eyepieces with much less eye relief.

My 10" Newtonian gives great views of M13 with a 10mm Radian. The Ring Nebula M57 is bright enough to go even higher in magnification. I've had the opportunity to try all of the Radians in my FLT132 apo: the lunar and planetary views are STUNNING. The images were clear even above 300x- I haven't tried to go higher yet. The Moon was more detailed than I had ever seen it, and I could see subtle colour changes visually on Saturn for the first time.

As far as unfocussed or "pin-cushion" effects on the edges of the field of view, I never had any problem with it in either the Panoptics or Radians. I have a parracor but never really use it. The only time I did see any distortion on the outer edges was on a cold night using the 10" Newtonian, and I suspect the primary mirror had not cooled down completely as the temperature continuously dropped during the entire viewing session.

Nowadays there are many different brands and types of eyepieces available. There are many with 82° or greater fields of view, and Tele Vue is presently releasing a new eyepiece called the "Ethos" with an incredible 100° field of view. It doesn't make the decision any easier, but if you have the opportunity to look through some at a local observatory or astronomy club viewing session, chances are you'll find something you will like. As for me, at least my eyepieces are one thing I don't have to worry about upgrading as far as I'm concerned.

For more information about these eyepieces:

Tele Vue website: Panoptic Eyepieces

Tele Vue website: Radian Eyepieces -----------------------