Older EP Designs

I am looking to augment my EP collection for my 8" LX200 and ETX 90. The set of Meade Super Plossls I have is: 6.4, 9.7, 12.4, 15, 20 and 26mm. I also have a 2x Barlow and a field reducer (.63). At 26mm the magnification is still quite high in either scope.

I'd like to maintain interoperability of the eyepieces. I don't think the ETX could handle a 2" EP and I don't have 2" diagonals for the LX200, so, I should stick to 1 1/4" barrels. Since both of these scopes are slow, I'm considering going forward with purchasing one of the older EP designs that were built for use in such scopes.

Here are a few concerns of mine:

Eye Relief:
I am an eye glasses wearer. Although I do have astigmatism, I can go without glasses at the eyepiece. However, for pointing the scope I need the glasses. This is the one argument I buy for getting contact lenses.)

I have found the Meade Super Plossls to have poor eye relief. Does this get any better with EPs in the 30-40mm range?

Contrast and Field of View:
I do most of my observing from my deck, which is in a light polluted area. While I do look at the planets as they make themselves available, I intend to use my optics to chase after Star Clusters, Galaxies and other faint fuzzies I can see from my yard and then occasionally observe in dark skies. I also plan to do much manual star hopping. The ETX which does not have GOTO will be my travel scope; I need to be able to scan with it.

Cost:
If an older and less expensive eyepiece design can fit my needs, why pay for an engineer to drum up something new?

So far, Kellner or Rank-Kellners are looking like a good match for my needs. Any suggestions?

Also, can I use the field reducer to help my cause?

Kirk, have you considered the Orion Epic ED-2 (or Celestron XCEL) design? 20mm uniform eye relief and darn near parfocal. They're cheaper than premium plossl's and perform very well in all my scopes. I've also got a nice pair of Seibert 24 Ultras for my binoviewer that are pretty nice, too. The limiting factor in FOV is that pesky 1.25" barrel. That's why the 40mm Plossl ep's have a narrow fov than the 32's. The relief on a 32mm plossl is pretty generous and your f6.3 reduce will let you get a pretty good chunk of sky. To really get a wide angle view with your 8", you'll need to go to 2" optics. With a 42mm GSO eyepiece and a 6.3 reducer I can get my 8" f10 SCT down to about 30x(!) and that's with around 70 deg fov.

Hi Kirk.

I have some of the same issues you've mentioned, including a need for wearing glasses and finding may eyepieces shy on eye relief. Just a couple of thoughts-

I've never tried a field reducer so I don't know how that would affect your visual observing. Also, I tried a 32mm Meade Super Plossl once and found that I couldn't use it with glasses (couldn't even come close, in fact...). With glasses, I *can* use the TVO 32mm Plossl and the Celestron 30mm and 35mm Ultimas. The pre-eyecup (older version) 32mm, 24mm, and 16mm Brandons also have good enough eye relief that you can see the entire field with glasses. The Brandons with eyecups do not have this eye relief.

I've recently started using "classic", 4-element orthos with a 2x barlow and extension tubes. I happen to be using UO eyepieces but there are Kasai and "Circle T" equivalents. With my particular barlow, the extension tubes I have give me magnification factors of 2.4x and 2.7x. The 2.7x combination, for example, makes the 18mm ortho the equivalent of a 6.7mm eyepiece. Adding a 12.5mm ep would obviously give higher magnifications. Purists would argue that a barlow degrades an image slightly and that longer extensions increase aberrations but I've never had a real problem with this setup. Anyway, with your scopes, you could probably get a range of useful magnifications with, say, a 25mm and 18mm ortho with a 2x barlow and sundry extension tubes. These eyepieces are relatively inexpensive, lightweight, and quite forgiving in terms of eye relief. For my eyes and in my scopes, they give very sharp, high-contrast images. They're not wide field eyepieces but if you can be happy with 40 - 45 degrees, they can do a nice job.

Best,
John

Respectfully, I don't think any Kellners or RKE's will be any kind of a cost effective upgrade over the ep/barlow combination you have.

Regarding eyeglasses: I have found an adjustable strap on my glasses to be of enormous benefit at the scope. Adjusted so the glasses stay up on my head, or forehead (depending on hat) when at the ep. I can then pull the glasses down in a wink to use the finder or charts. This works much, much better than glasses dangling around my neck, or worst yet, set aside somewhere on a table or in a pocket.

Regarding older ep designs, due to your long focal ratios, most of the simple and affordable wide field designs will work well. This has been my experience. My 2 cents is to not duplicate any ep focal length combo's you already have. At least not right away!

John