Eyepieces - Less glass is more

[FaintFuzzies]

Other viewpoints? You came to the right place <g>. The differences among the various eyepieces that are easily seen in the 48" simply cannot be seen in my 25" or 30". I have a full set of UO volcano tops which rarely get used because, after extensive A/B comparisons with my Nagler T6 set, I can see no discernible difference in contrast, light grasp, or, for lack of a specific word, detectability of objects in my scopes. With all else equal, I prefer the wider apparent field.

Both Jimi and I do see the difference in his scope, and neither he nor I see the difference in my scopes. We have discussed this phenomenon ad infinitum, and a couple of years ago we asked James Mulherin for a professional opinion. His theory was that it's a matter of small percentage differences that yield a large enough absolute difference in the larger aperture to cross the threshold of detectabiity, while remaining unnoticeable in the smaller scopes.

On the other hand, at GSSP 2009, five observers, including Jimi and I saw the difference between the ZAO-II, UO HD and Ethos (all 6mm) in my 22". The UO HD is between the ZAO-II and Ethos, but a little closer to the ZAO-II in light transmission and the ability to perceive additional detail. Jimi and I agreed that the difference between the ZAO-II and the Ethos is obvious. Lastly, one of the five was a beginner and even he saw the difference.

One of the object we were looking at was the triple galaxy system, NGC 6745 in Lyra.

[Jim Chandler]

These comparisons of high quality eyepieces don't necessarily have clear cut results. It's a classic "your mileage may vary situation".

By way of example, at TSP the year Televue introduced the Ethos, Al Nagler was wandering the upper field with the Ethos 13mm in his pocket. Jimi, Mike Sowell, and I were using my 25" and Al came by and said "try it". We popped it in and looked at M13, were impressed by the contrast, and proceeded to compare the 13 Ethos with my 13 T6 Nagler. All three of us saw a clear improvement in contrast and brightness in the Ethos. We were impressed, to say the least.

After the Ethos 13 hit the market, I acquired one and used it extensively over a period of months, frequently comparing it to my 13 T6. The results? Maybe 1 object in 10 or 20 looked better in the Ethos, another one looked better in the T6, and the vast majority of objects looked pretty much the same in either eyepiece. In the intervening years, I've done the same comparison in the 18" and the 30" with pretty much the same results. No "aha" moment; just a lot of head scratching.

[Adrian R.]

[


After the Ethos 13 hit the market, I acquired one and used it extensively over a period of months, frequently comparing it to my 13 T6. The results? Maybe 1 object in 10 or 20 looked better in the Ethos, another one looked better in the T6, and the vast majority of objects looked pretty much the same in either eyepiece. In the intervening years, I've done the same comparison in the 18" and the 30" with pretty much the same results. No "aha" moment; just a lot of head scratching.[/QUOTE]


Wow, my experience comparing the Ethos eyepieces to Naglers have been quite different. However, I should announce that this was comparing them to type 4 Naglers. I found the Ethos eyepieces to produce better contrast, sharpness, of course APOV..and in the end the greatest delta was in color neutrality. Objects just appear more 'color correct' giving the observer a greater sensation of observing unaided. I found them to be far better planetary performers as well due to this advantage. Maybe one day I will get a chance to compare them to a type 6 Nag.

[Adrian R.]

I recently acquired a collection of older, simple 1.25" eyepieces. In this collection were some Brandons, a UO Ortho, EDS Ortho and various Plossl type eyepieces. I compared them while observing planets, and truly could not detect any difference in all areas with respect to image quality. However, what I could detect was a huge difference in comfort and presentation. The modern eyepieces were just far more entertaining and as such, allowed for more enthusiasm in practice making the experience far more engaging and productive thus seeing more. Within a week they were all sold off on A/Mart.

I have not though used these types of eyepieces while viewing DSOs, and I am positive that there is definite truth to the OP's testimony. Following the laws of physics, this just makes sense. The basic premise is always the same. To 'get' something more, you need to 'give' something more. The less glass light has to travel through, the less chance there is for optical corruption. You can even these disparities through engineering and design, but in the end there will always be some degree of compromise of which can be observed.

Eyepieces are some of my favorite inanimate things in life. Their importance in contribution to the focused image can NEVER be overestimated. The eyepiece is the 'interface'..or connection between material and flesh. Its interpretation is that of the entire optical system; including itself. This is where the subjectivity lies...

[Tony B]

Some years ago when Jupiter was at opposition and the seeing was near perfect I got stunning views through a 14.5 inch F 7 dob using a 13.8mm Meade Wide field eyepiece. My club members were lining up for the view of cloud bands so pronounced that they looked brown. Yet on putting in a 13 mm Nagler the view was pale and washed out by comparison, and at the time I thought that the extra glass in the Nagler was to blame.

[PeterN]

How do the Delos eyepieces stack up against these simpler eyepieces? I like the big eye lens and 20mm eye relief of the Delos. What about Brandons? Brandons have great contrast, but I'm not sure of the light transmission level. I use both of these.

On the other hand, at GSSP 2009, five observers, including Jimi and I saw the difference between the ZAO-II, UO HD and Ethos (all 6mm) in my 22". The UO HD is between the ZAO-II and Ethos, but a little closer to the ZAO-II in light transmission and the ability to perceive additional detail. Jimi and I agreed that the difference between the ZAO-II and the Ethos is obvious. Lastly, one of the five was a beginner and even he saw the difference.

One of the object we were looking at was the triple galaxy system, NGC 6745 in Lyra.

[Tony B]

Being a bit dated in some respects I have 6, 10, 16, and 25mm Clave plossls which I often use with a Clave Barlow, but on planets without the Barlow for max light transmission . Though over 30 years old they can still hold up well against many newer designs, though I sill like my Naglers and other wide fields.