Plossls vs Naglers

I saw this article on cloudy nights and I am just wondering what you guys thought of it. I found it to be interesting and just wondering if most people agreed with it or not. thanks

http://www.cloudynights.com/eyepieces2/performance.htm

As one who's owned Naglers, Plossls, orthos, Konigs and Kellners, I'd say I generally agree. The simpler designs do seem to have an edge in sharpness and contrast, the better quality ones anyway.

That said, the Naglers are still excellent themselves (especially considering the number of elements), and there is the question of detail vs. enjoyment. The big multi-lens eyepieces have that immersive 'spacewalk' effect. If you like HDTV but don't care how big or small the screen is, then the simple designs are for you. If you don't care quite as much whether it's quite as HD but want that big, projection-screen 3-D stereo SurroundSound experience, you go for the Naglers.

I think both scopes used had slow f-ratios. For planetary purposes, simpler designs do tend to work better, or at least as well, in that circumstance. With fast scopes, however, there can be a different story, at least when a quality Barlow is not also used. Many people still prefer the simpler designs in fast scopes for less scatter and the benefit that gives to contrast, but the simpler designs may also represent a compromise in sharpness due to their inferior levels of correction. Generally, when used in a fast scope, the simpler designs require that the planetary detail be centered and stay centered, and this is best accomplished with a GEM. With Dobs, tracking is required. Even with an equatorial platform, precise centering and perfect collimation are required in fast Dobs for the simpler designs to keep up in sharpness (i.e., without a Barlow to slow the system).

Hmm, this is a real bucket of worms.
First, a Plossl is a good overall EP for just about any purpose. As a planetary EP it does not excel but it does compare.
All Plossls might be similar, but the better ones are superior to the cheaper ones. A good TV Plossl is better than a Meade 5000 Plossl without a doubt in my eye.
For pure planetary the Orthos are quite good. Short eye relief is their worst trait. The other problem is FOV, which in a tracking scope is not an issue.
I won't get into whether it is worth the money for the premium EPs, because it is a personal choice if you ask me. I for one own the premium brands and types because I found them to be more pleasing to the eye.

Hi Justin,

First of all, don't believe everything you read on the Internet. That goes for articles on "Cloudy Nights." Quality of the articles vary and most contain limited, subjective opinions based on little or no data.

There are no perfect eyepieces, just as there are no perfect telescopes, cars, washing machines, or any other product. Each product has its advantages and disadvantages. It is a matter of personal preference which set of advantages and disadvantages you select.

I recommend you read all the other articles on eyepieces: http://www.cloudynights.com/premium2/eyepieces.htm They contain a lot more information than the article you cited. As you read, note what telescopes and types of objects were used to evaluate eyepieces.

What you'll find is that the "best" eyepiece depends on a lot of factors - your goals and preferences, telescope design, observing targets, observing conditions, observer's skill, your pocketbook, etc.

I own or have owned a variety of eyepieces (orthos, plossls, konigs, lanthanums, panoptics, naglers) from a variety of manufacturers. I've spent considerable time evaluating all of them over a period of months or years in a variety of conditions. The best advice I can give is use what you read or hear as a guide. But you'll have to use eyepieces in your scope for quite some time before you can decide whether they meet your needs. If you are a serious observer, you'll likely have specialized eyepieces for certain types of observing. If you are a casual observer, you'll likely notice little difference in performance, but you'll notice things like field of view and eye relief right away.

For example, serious planetary observers generally prefer simple eyepiece designs with exceptional on-axis sharpness and contrast. However, if you filled your eyepiece case with the "best" eyepieces recommended in an article on planetary viewing, you'll likely be very disappointed. The "best" planetary eyepieces usually have a narrow field of view and an even narrower "sweet spot" where the performance is optimal. You'd better have a tracking scope or you will rarely experience the best performance. In an undriven dob, the object will quickly drift outside the "sweet spot" and then outside the narrow f.o.v. In addition, with fast scopes, the off axis performance of basic designs is quite poor. Star clusters will look far better in Naglers that are designed for fast scopes.

Simple planetary eyepieces generally also have very short eye relief (in the focal lengths used for observing planets). If you must wear glasses, you might as well not even bother evaluating them. In the longer focal lenghts, the eye relief of orthos and plossls is comfortable.

That being said, I prefer the new Nagler T6's for observing star clusters and hunting faint fuzzies in my scopes. I generally use 12-1/2" - 18" reflectors with f/# around 4.5-5. The old 9mm Nagler was a superb eyepiece. Except for the smaller size and weight, the performance of the new 9mm T6b seems the same. However, the 5mm and 7mm Nagler T6's have noticeably better contrast than their previous counterparts (4.7mm and 7mm) as well as better eye relief. Most of the time, they even provide very good views of the planets. It takes some rare, exceptional seeing to distinguish the views between these Naglers and simpler eyepiece designs. The 7mm Nagler T6 is in my focuser at least 90% of the time.

For seeing really gets good, I bring out the simpler orthos and plossls for planetary viewing.

In summary,
1) Be clear of what YOUR goals and constraints are.
2) Eyepiece performance can vary greatly among scope types and focal ratios. Consequently, pay the most attention to opinions voiced by people who are using the same scope as you have.
3) Eyepiece preference is very subjective. What different people think depends a lot on what they value - what their goals are. So, don't pay too much attention to other people's opinions. Only yours matters. Consequently, try (in your scope) before you decide which eyepieces to keep.

Albert

Justin De Guire said:

I saw this article on cloudy nights and I am just wondering what you guys thought of it. I found it to be interesting and just wondering if most people agreed with it or not. thanks

http://www.cloudynights.com/eyepieces2/performance.htm

Hi Justin,

I tend to agree with the Cloudy Nights article. I use my Celestron/Vixen Silvertop plossls for planetary in my SCT's. It just so happens when seeing allows my Celestron Silvertop 10mm plossl gives me beautiful color saturation, contrast, and sharpness on the planets. The above eyepieces seem to perform better than the Naglers I have tried. For deepsky in my SCT's, I ultimately prefer erfles and konigs as long as they are well corrected. Two of my favorite eyepieces in a C11 are the University Optics 32mm (2"), and the 24mm (1.25") konigs. I also own a Meade Research Grade 20mm erfle in pristine condition which has excellent correction, and is wonderful on globulars. I won't begin to talk about the comparisons I have made, but I simply feel that the UO Konig eyepieces are just as contrasty as the Naglers, and sharper like orthos. If I didn't have my Silvertop set, I would definitly buy University Optics orthos for the planets. Really a no brainer. These are great eyepieces at a great price. I think a very nice, and high quality set of eyepieces for a SCT would be the University Optics 32mm (2"), and 24mm (1.25")Konigs, 18mm, 12,5mm, and 9mm orthos. You might want to add a 40mm, and a barlow as well. I would consider this a best bang for the buck.

On the other hand... I have a Discovery 13.1" f/4.5 dob, and I exclusively cannot live with out the Televue 26mm, 17mm type 4, 13mm, and 7mm type 6 Naglers for deepsky. The wide field (porthole effect), contrast, eye relief, and exit pupil make these as close to the perfect eyepieces for my dob I have found to date. I also find the 13mm, and 7mm type 6 Naglers to be very fine planetary eyepieces as well.

There are many variables involved in eyepiece selection, and this is just one spin on it from an amateur astronomer.

Clear skies,

Joe

P.S. Here come the chinese eyepieces...