I suppose it depends on if you want more than a 50° FOV I reckon. Erfles usually do well in slow scopes, so if you wanted low/medium magnification and a wider angle they'd be better than a Plossl in some ways. From what I've been told orthoscopics are very good in slow fracs, and it's difficult to beat them for contrast, they'll only give you about 42° FOV though.

There's Plossls and Plossls though. My TV 40mm cost more than my ST80 OTA.

 

You're welcome. I reckon this would be good in your scope.



http://agenaastro.com/gso-15mm-superview-eyepiece.html

 

Have a good one!

 

I have a lot of Plossls:

1/ 6mm Vixen NPL (x2)

2/ 6mm Solomark

3/ 6mm GSO

4/ 6.3mm Sky-Watcher

5/ 6.4mm Meade

6/ 8mm Vixen NPL

7/ 8mm TeleVue

8/ 9mm GSO

9/ 10mm Vixen NPL

10/ 10mm Orion Sirius

11/ 11mm TeleVue

12/ 12mm Celestron Omni

13/ 12mm GSO

14/ 12.4mm Meade

15/ 13mm Celestron

16/ 15mm Celestron Omni

17/ 15mm GSO

18/ 15mm Meade

19/ 15mm Vixen NPL

20/ 15mm TeleVue (x2)

21/ 17mm Celestron

22/ 20mm TeleVue

23/ 25mm Vixen NPL

24/ 25mm Orion Sirius

25/ 25mm TeleVue

26/ 25mm GSO

27/ 26mm Meade (x2)

28/ 30mm Vixen NPL

29/ 32mm TeleVue

30/ 32mm Celestron

31/ 32mm Baader BCO (x2)

32/ 32mm Revelation (GSO)

33/ 40mm TeleVue

34/ 40mm Celestron

I've had more in the past but these are the only ones now unborked and usable. Some have been slightly customised. All of the paired Plossls except the 6mm Vixen are for my binoviewer. I had to replace the drawtube on the older 6mm Vixen NPL and while I was waiting to find a suitable tube I acquired another 6mm NPL. It's probably the best 6mm Plossl in existence. Very tight eye relief though.

Celestron don't actually make any Plossls. They are owned by Synta (Sky-Watcher) and most Celestron, Sky-Watcher and *Orion Plossls are actually made by Barsta (BST). I'm not sure about the Omni series, I have a feeling they are custom made for Synta by Barsta. There is a Barsta made Celestron/Sky-Watcher 17mm Plossl. They are often included in Celestron sets, but if you want it Stateside you may have to buy the Orion Sirius version, probably for twice the price of the Sky-Watcher.

*The distributor Orion USA as opposed to Orion UK who are a telescope manufacturer. AFAIK Orion UK don't make eyepieces either.



It's regularly stated that the best Plossls are TeleVue, they are very good with a superb build quality. Which is mostly what you pay for, and the fact they are made in Japan. In scopes slower than f/6 though I think Meade, GSO and Vixen Plossls hold their own. I have a 12mm Omni with a chrome/brass drawtube. One night I mistook it for the 11mm TV in my 90mm Orion Mak. In fact, I thought it gave a slightly better view lol.



Above: Celestron and Revelation 32mm Plossls. The 32mm Revelation is a rebadged GSO. Revelation is the house name of products sold by Telescope House in England. There isn't much between these, the Celestron came out of an old kit. Being a Barsta 32mm it doesnt actually quite have a 50° FOV unlike the GSO. I think the 32mm GSO has a slight edge and will probably be better in fast scopes.

I'm not sure about the SvBony Plossls, my Solomark 6mm Plossl is surprisingly good for what it cost. The GSO Plossls are well made and although they have slightly longer aluminium drawtubes (30mm), the undercut bottom lip is flared not unlike TeleVue drawtubes. So it's easy to extract from anything with a compression ring. GSO are slowly phasing out the undercuts, possibly as they are universally disliked, although ironically GSO undercuts actually work. My 32mm and 25mm GSO Plossls have no undercuts. So a GSO set sounds like a good move. I'd put them up against TeleVue Plossls even in fast scopes.

 

These are pretty nice EP's for the money. A little like a budget Panoptic. I saw Comet Johnson with the 15mm SuperView and an Astronomik UHC-E filter.



I think most of the range are some form of modified Erfles.



Although I suspect the 15mm is actually a Bertele.



Many so called 60° five element 'Super Plossls' are really Erfles. The Bresser five element 60° Super Plossls are one of the most well known versions this side of the Atlantic. I don't think they're easily available Stateside though.



They seem to be good in a bino, unfortunately I haven't had time to really test the 20mm pair in my WO bino.



All of these 'Erfles' work well in anything f/6 and slower though. I think the 15mm or 20mm GSO SuperView would work quite well in your scope for wide angle low power views.

 

That's pretty usual with 40mm Plossls, it's why they're disliked by many. They can take some getting used to. You can see the eyeguard extender I've put on this 40mm TV Plossl to help with eye positioning.

 

Some good discussion so far. I will add my 2 cents.

From an edge correction, F10 and F 13 scopes are reputed to be very forgiving of lower cost eyepieces when it comes to image quality and edge correction. So, I think your post refers to this factor.

As discussed, you may wish to have wider than 52 degree AFOV eyepieces so, from that point of view you would need to go to something other than a Plossl. However there are lower cost wider AFOV eyepieces that are moderate in cost and there are the expensive ones which typically are better corrected at the edges. In these scopes you may not see a significant difference at the edge between the lower cost and the higher cost eyepieces. I have not tested this but it seems likely.

I have F5, F5.9 and F 15 scopes and I use the same eyepieces in all of them. I have a variety of eyepieces available but I use my zooms most of the time.


As far as too much eye relief, yes that can be an issue. I have Celestron and a Gosky 32 mm Plossl eyepieces and they have a bit more eye relief than I would like. As a result I have to carefully position my eye over the eyepiece or I get blackouts. They are about the same in this regard. So I don't think you got a lemon. I think this is a byproduct of the design.

I also have Orion, Meade and some unbranded Plossls. They all seem pretty good.

 

Hiya Pleiades -

That little Erfle Mak suggested won't be a problem with an 18mm ER (eye-relief). And at 60° - 68° FOV (field of view), it should be a nice departure to the classic Plössl in your 60mm F/13 achromatic-refractor. I'm sure Mak has already gotten you aware that "Super-Plössl" is usually actually an Erfle EP (Eyepiece). Forgive my short-course in astro-abbreviations.

Allow me to toss you a nice & colorful chart of Eyepiece-Designs:




I have one of these printed & hanging on my wall next to this machine I'm using. Don't ask me what the story is on the rectangle of colors/numbers/letter in the lower-right. I just ignore it. Here's another chart I also like:





I just got a nasty surprise. I was going to introduce you to a place that has some nice eyepiece that most people never see - as it's a smaller outfit that advertises word-of-mouth mostly - that have always impressed me. Called University Optics and operating from Ann Arbor, Michigan. And the website seems to have been purposefully disabled -

http://www.universityoptics.com/

I was planning on showing you a nice EP or 2 for your trusty, ol' Tasco. I'll go hunting and see if I can't possibly locate similar from elsewhere for you, Pleiades. I grew-up (maybe) surrounded by the venerable 60mm Tasco telescopes. It was THE telescope kid's always got from their parents. I was the weirdo - having a 3" F/15 from 'Edscorp' - Edmund Scientific. I'd done enough research to suggest this to my parents over a 60mm Tasco everyone else had. But I recently found out that most every amateur refractor out there had lenses made by the same outfit in Japan: Carton Optical Industries. Tasco, Edmund, Unitron, name it!

All the time I pined-away for a Unitron - wasted.....

Off to the Hunt...

Dave


Your namesake in Stellarium:

 

My favorite place to look for eyepieces is www.agenaastro.com , the sponsor of this forum. They have a great selection and have the best search and select of any site I visit. Prices are great and delivery is fast.


Eyepiece Designs - This is the one I turn to when I am trying to understand or explain the
differences between the various designs. There are many different designs, Many are named
for their original designer, such as Huyghens, Ramsden, Kellner, Plossl, Konig, Erfle, Branden and Nagler.
http://www.chuckhawks.com/common_eyepiece_designs.htm

 

Speaking of myths, the 52° Plossl is almost certainly a myth lol.



The 40mm TV Plossl on the right has an AFOV of 43° with a field stop of 27mm. The eye relief is 28mm; one millimetre bigger than the field stop! The Celestron 40mm has the same AFOV but a whopping 31mm of eye relief. It's not too bad to use, but the eyeguard on the TV really helps with its eye relief.

 

I just read the specs, I don't actually measure the AFOV of any of my eyepieces.

But why would you say this is a myth?

 

It's basically a marketing ploy. TeleVue don't claim an extra 2° with their Plossls. It all depends how honest you are being when the AFOV is calculated. From what I can gather a Plossl can actually only have a 50° AFOV.

I think it's not unlike 50° Baader BCO's. They're actually about 42° like all orthoscopics but the field stop is enlarged to give the extra field to aid target acquisition.



Both of the above eyepieces are 18mm orthoscopics. An Astro Hutech and a Baader Classic Orthoscopic. The AH has a 12.5mm field stop, 15.21mm eye relief, 15mm eye lens and a 42° AFOV (according to Astro Hutech). Making it fairly typical for an 18mm orthoscopic.


The BCO has a 16.8mm field stop, 14.7mm eye relief, 15.8mm eye lens and a 52° AFOV (according to Baader Planetarium).

Both EP's are similar except for the field stop and AFOV. The 4.3mm extra field stop of the Baader accounts for the extra 10° AFOV. However, it isn't sharp in the 10° near the EOF as it is a normal orthoscopic, which can only ever have about a sharp 42° AFOV.

 

Definitely a myth. I have (to many) long refractors and actually prefer Orthoscopic and Monocentric (Steinheil and Hastings) to Plossl eyepieces. Better colour rendition and clarity to my eye.
When getting into higher magnifications (smaller exit pupils) doing planetary viewing there is more chance of ghosting with a Plossl compared to Ortho.
One of my favorite eyepieces for my Antares 105mm f/15 is a Edmunds 12.5mm Hastings triplet.
Erfle designs also work very well and if you do not mind used, the 1.25" Masuyama excel at focal lengths above f/7
The Bresser/ ES 70° AFOV horribly misnamed Plossl (5-6 elements and 70° is not a Plossl) are also good in longer focal length scopes and will not break the bank on you.

 

Just to add to the answer Pleiades, in longer focal length refractors the need for highly corrected wide field eyepieces is minimized by the focal length.
Widefields have to be corrected for AMD and RD to a much higher degree so end up being much more expensive.
Compare the price of a Panoptic to a Konig or Erfle! All will work very well but only the Panoptic will work perfectly in a shorter faster telescope.
But then you have the Masuyama that is designed for scopes f/7 and slower that will really bring out the view in a long focal length refractor and are just as expensive as a Panoptic.