25 replies to this topic

[idahoeng]

Hello All,

 

I have a 32mm Plossl that has no brand name.  It looks like the Orion Sirius or Meade 4000 32mm, so probably the same manufacturer.  In usage alongside my Orion Sirius 25mm Plossl, the 32mm has been fine and I haven't noticed any differences compared to the 25mm, other than magnification, of course. 

 

Most likely I will upgrade my 25mm and a few of my other eyepieces over time.  I'm wondering if I should look at a better 32mm Plossl, such as an Orion, Meade, or Celestron version.  Of course, there is the Televue option, but I don't think I'm there yet in my astronomical journey.  My telescope is a SkyWatcher 102mm f/5 achromat, so I'm not in the high end of equipment by any measure.

 

In comparing my non-branded 32mm to my Orion Sirius 25mm, I see the following.

 

Non-branded 32mm

- marked as fully multi-coated

- reflections in the lenses: all reflections are green tinted

 

Orion Sirius 25mm

- marked as multi-coated

- reflections in the lenses: some are green tinted, some are light pink to white (not fully reflecting a white light source)

 

With the "fully multi-coated" marking and the green tinted reflections in the 32mm, it seems to me this is probably already a pretty good eyepiece and may not need an upgrade at my level of astronomical experience.  But I invite your comments on the differences between these eyepieces and any thoughts of upgrading.

 

Thank you as always,

 

IdahoEng

 

 

 

 

 

[Rick-T137]

In my opinion, you're not going to get any significant increase in performance by replacing your existing Plössls with brand-name ones.

 

I'd recommend you look at something like the Astro Tech Paradigms. They are a step up from the Plössls and offer a wider field of view. And they aren't terribly expensive:

 

https://www.astronom...iece_series=478

 

Of course, there are even bigger upgrades to be made - but the Paradigms are likely a good place to start.

 

Clear skies!

Rick

[idahoeng]

Hi Rick,

 

Thank you for your comments.

 

My plan is to replace the 25mm Plossl with the Celestron XCEL-LX and to add the 12mm and 8mm Paradigms.  That's the first step plan ... then my self-control may be tested.

 

IdahoEng

[vtornado]

Chances are your no-name plossl is from the same factory and has the same specs as a named plossl.   For example Celestron plossls are typically rebranded GSO.

 

Depending upon your light pollution and your eyes, 32mm might be too low power for an f/5 telescope.   This produces an exit pupil of around 6mm, which may exceed your dark adapted pupil size.  For my eyes and my skies I like a 5 mm exit pupil.   That is 25mm at f/5.   

 

For a true upgrade you may want to consider a celestron xcel-lx 25mm eyepiece.

It has roughly the same field of view as the 32mm plossl, but the higher magnificatin results in a 5mm exit pupil.  The field of view will be more corrected off axis.

 

Technically fully mulit coated is best.  because it means every air to glass sruface is mutli-coated, which should mean less scatter and higher transmission than single coated, multi-coated etc.  But ... at the low end of eyepieces, the specs are not always adhered to.  

 

I did purchase a few of the svbony 207 series plossl, and I thought they were better than the run of the mill chinese plossl, but only slightly so.  I don't know if they are availble any more.  I got mine cheap.  This one is $44 + Tax.  

 

https://www.ebay.com...c3e9b606a1db76d

Edited by vtornado, 15 August 2024 - 01:16 PM.

[deSitter]

All Chinese Plossls are not made the same. My newbie friend got some low-cost Plossls as a starter kit on my recommendation. They are fine, but they don't compare to my Meade Series 4000s from the early 2000s. All of those have razor sharp, jet black field stops, every one. Those are highly recommended.

 

-drl

[Bob4BVM]

All Chinese Plossls are not made the same. My newbie friend got some low-cost Plossls as a starter kit on my recommendation. They are fine, but they don't compare to my Meade Series 4000s from the early 2000s. All of those have razor sharp, jet black field stops, every one. Those are highly recommended.

 

-drl

True.

 

And further, NONE of the Chinese plossls, including the later Chinese Meade so-called "super plossls", can compare to the true Meade Super Plossls from Japan circa 1980-1990.

 

Unlike the later china versions by the same name, those from Japan were 5-element designs, and still are at the top of the heap when it comes to plossls.

[vtornado]

Your 2000s may be Taiwanese vintage, (I have a set of the Meades and they are very nice).  I assume comparing 2020+ no-name  plossl to a mead/orion/celestron/svbony/ plossl will be about the same.  There is probably run variation as well.

 

Meade kept on using the same name despite design changes.  5 elements/Japan/Taiwan/China ...  all are labeled Meade 4000 super-plossls.

 

It might be a wise for  our original poster to shop for some older plossls.  I bought mine off this site for around $20.00

 

Sterling plossls and their clones were considered better than the standard fare. Vintage Antares and Orion Highlight plossls are considered better too.

 

One thing about the meades is that the the longer f.l. versions have a deeply resessed eye lens.  Good in that it helps with eye plaement, may not work well for glasses wearers.

Edited by vtornado, 15 August 2024 - 02:06 PM.

[scopeboy42]

 

One thing about the Meade's is that the the longer F.L. versions have a deeply recessed eye lens.  Good in that it helps with eye placement, may not work well for glasses wearers.

I observe without my glasses on so the deep recess on the yellow lettered Meade 32mm Plossl makes it my favorite. Does not come up to the higher quality of some of the nicer ones like Televue but it sure is more comfortable to use. It is the only 32mm Plossl I don't have any black out problems.

[MisterDan]

Keep in mind: your 32mm is yielding ~15-16x in your StarTravel.  I myself would be hard pressed to discern much difference between one good 32mm "standard field" eyepiece versus another at that magnification.  Years ago, I found myself with a 30mm Orion Ultrascopic (5-element symmetrical) and a 38mm-format Pentax 30mm Kellner (rare and primo).  Other than an inconsequential difference in apparent field (perhaps a degree or so), their views at ~16-17x were indistinguishable in my EDHF.

 

I myself would consider - as vtornado suggested - a wider-field and shorter-focal-length eyepiece like the X-cel or Paradigm/Starguider.  Get a bit more magnification, a more "versatile" exit pupil, and effectively the same true field of view.

 

Best wishes.

Dan

[sevenofnine]

+1 on Rick-137's advice. I upgraded my basic plossl's to Astro-Tech Paradigm/Agena Astro Starguider ED's and the improvement is very noticeable. I liked them so much, eventually I bought them all 

[Rick-T137]

All Chinese Plossls are not made the same. My newbie friend got some low-cost Plossls as a starter kit on my recommendation. They are fine, but they don't compare to my Meade Series 4000s from the early 2000s. All of those have razor sharp, jet black field stops, every one. Those are highly recommended.

 

-drl

I have some Meade Series 4000s from the late 90's and early 2000's, and they are fine. But to say the current Chinese Plössls "don't compare" is a bit of an exaggeration. The Meades may have better defined field stops and may be marginally sharper, but it would hardly be a worthwhile investment to "upgrade" to them from existing Plössls, in my opinion.

 

Clear skies!

 

Rick

[rgk901]

Hi Rick,

Thank you for your comments.

My plan is to replace the 25mm Plossl with the Celestron XCEL-LX and to add the 12mm and 8mm Paradigms. That's the first step plan ... then my self-control may be tested.

IdahoEng

good plan, nice eyepieces

[Jon Isaacs]

I have some Meade Series 4000s from the late 90's and early 2000's, and they are fine. But to say the current Chinese Plössls "don't compare" is a bit of an exaggeration. The Meades may have better defined field stops and may be marginally sharper, but it would hardly be a worthwhile investment to "upgrade" to them from existing Plössls, in my opinion.

 

Clear skies!

 

Rick

 

I believe the true Meade Super Plossls were from the early 1990s. By April, 1996 when Sky and Telescope did the comprehensive Plossl test, the Meade Plossls were just regular 4 element eyepieces.

 

At a F/12, just about any Plossl should be fine.

 

Jon

[SeattleScott]

I agree

[hambone20]

A nice 28mm would replace both of those eyepieces. 

[deSitter]

Chances are your no-name plossl is from the same factory and has the same specs as a named plossl.   For example Celestron plossls are typically rebranded GSO.

 

Depending upon your light pollution and your eyes, 32mm might be too low power for an f/5 telescope.   This produces an exit pupil of around 6mm, which may exceed your dark adapted pupil size.  For my eyes and my skies I like a 5 mm exit pupil.   That is 25mm at f/5.   

 

For a true upgrade you may want to consider a celestron xcel-lx 25mm eyepiece.

It has roughly the same field of view as the 32mm plossl, but the higher magnificatin results in a 5mm exit pupil.  The field of view will be more corrected off axis.

 

Technically fully mulit coated is best.  because it means every air to glass sruface is mutli-coated, which should mean less scatter and higher transmission than single coated, multi-coated etc.  But ... at the low end of eyepieces, the specs are not always adhered to.  

 

I did purchase a few of the svbony 207 series plossl, and I thought they were better than the run of the mill chinese plossl, but only slightly so.  I don't know if they are availble any more.  I got mine cheap.  This one is $44 + Tax.  

 

https://www.ebay.com...c3e9b606a1db76d

Coating always increase scattering. It's a trade-off between transmission and scattering. Super-critical applications e.g. involving lasers use uncoated optics to minimize scattering. "Multi-coating" although real is more of an advertising buzz-phrase that a real performance issue, Most eyepieces are sold by the buzz, not actual performance.

 

-drl

[PKDfan]

Hello All,

I have a 32mm Plossl that has no brand name. It looks like the Orion Sirius or Meade 4000 32mm, so probably the same manufacturer. In usage alongside my Orion Sirius 25mm Plossl, the 32mm has been fine and I haven't noticed any differences compared to the 25mm, other than magnification, of course.

Most likely I will upgrade my 25mm and a few of my other eyepieces over time. I'm wondering if I should look at a better 32mm Plossl, such as an Orion, Meade, or Celestron version. Of course, there is the Televue option, but I don't think I'm there yet in my astronomical journey. My telescope is a SkyWatcher 102mm f/5 achromat, so I'm not in the high end of equipment by any measure.

In comparing my non-branded 32mm to my Orion Sirius 25mm, I see the following.

Non-branded 32mm
- marked as fully multi-coated
- reflections in the lenses: all reflections are green tinted

Orion Sirius 25mm
- marked as multi-coated
- reflections in the lenses: some are green tinted, some are light pink to white (not fully reflecting a white light source)

With the "fully multi-coated" marking and the green tinted reflections in the 32mm, it seems to me this is probably already a pretty good eyepiece and may not need an upgrade at my level of astronomical experience. But I invite your comments on the differences between these eyepieces and any thoughts of upgrading.

Thank you as always,

IdahoEng

Hi IdahoEng !!


Your scope is probably not going to show a difference quite honestly so i'd buy an eyepiece that goes a bit deeper like mine own circumstance where i go from a 30mm to a 20mm directly then to a 12mm with my small apo.

If you had exceptional optics and skies then an upgrade might be in order but for now your A-OK.




Good hunting !!



Clear Skies
Lance

[Tweel]

Hi Rick,

 

Thank you for your comments.

 

My plan is to replace the 25mm Plossl with the Celestron XCEL-LX 

 

That is what I did and the 25mm Xcel is a significant upgrade, visually, and ease of use. I stuck with the Xcels though. Instead of buying a better 32, buy a wide field 82 degree or better, 20-25mm. 

[deSitter]

True.

 

And further, NONE of the Chinese plossls, including the later Chinese Meade so-called "super plossls", can compare to the true Meade Super Plossls from Japan circa 1980-1990.

 

Unlike the later china versions by the same name, those from Japan were 5-element designs, and still are at the top of the heap when it comes to plossls.

I hope I can get my hands on a pair of those 5-element Plossls, but that is a stretch to call a 5-element design a Plossl. By Plossl is meant, really, 4-element achromatic Ramsden. The good ones are extremely sharp. I may have lucked out, but my China set are absolutely excellent across the board.

 

There were wide angle Erfle derivatives in the 4000 line, the QXs. They are awesome in long scopes. Those are also 5-element. But there is some variation in performance across the 4 focal lengths. The achromatic symmetrical Ramsden - call it a Super Plossl - 4000s are just equally good from 56mm down to 6.4mm. The 56mm is a killer eyepiece in long scopes.

 

-drl

[deSitter]

I have some Meade Series 4000s from the late 90's and early 2000's, and they are fine. But to say the current Chinese Plössls "don't compare" is a bit of an exaggeration. The Meades may have better defined field stops and may be marginally sharper, but it would hardly be a worthwhile investment to "upgrade" to them from existing Plössls, in my opinion.

 

Clear skies!

 

Rick

I do maintain that there are quality variations - how could there not be?

 

The 4000s Plossls must have been made under very strict quality control at one time. If the spacing between the elements is not perfect, the field stop will be fuzzy, or even blue-fringed. The no-names are highly variable. They are likely 2nds that work, but are not of minimum standard for some sellers. Meade always got the best out of their optical partners. I have seen many 4000s other than my own set and they are uniformly excellent in both construction and performance.

 

I would expect that GSO use similar quality standards. Those are surely good eyepieces.

 

-drl

[Bob4BVM]

I hope I can get my hands on a pair of those 5-element Plossls, but that is a stretch to call a 5-element design a Plossl. By Plossl is meant, really, 4-element achromatic Ramsden. The good ones are extremely sharp. I may have lucked out, but my China set are absolutely excellent across the board.

 

There were wide angle Erfle derivatives in the 4000 line, the QXs. They are awesome in long scopes. Those are also 5-element. But there is some variation in performance across the 4 focal lengths. The achromatic symmetrical Ramsden - call it a Super Plossl - 4000s are just equally good from 56mm down to 6.4mm. The 56mm is a killer eyepiece in long scopes.

 

-drl

You are right of course, it's a stretch to call a 5-element design a Plossl.  But that's what Meade did when the released the originals in the 80's.  I always wonderd what the design really is, does anyone have a lens diagram of the old 5-element SP's ?

 

BTW I now have a pair of the original SP's in 56mm for my BT. They just barely fit my 65mm IPD, but for some targets the view is amazing thru them.

[MisterDan]

You are right of course, it's a stretch to call a 5-element design a Plossl.  But that's what Meade did when the released the originals in the 80's.  I always wonderd what the design really is, does anyone have a lens diagram of the old 5-element SP's ?

 

BTW I now have a pair of the original SP's in 56mm for my BT. They just barely fit my 65mm IPD, but for some targets the view is amazing thru them.

Meade (Kowa-made) Super Plossls (cross-sectional diagram):

https://www.cloudyni...ram/?p=10702784

 

Cheers.

Dan

[drspiv]

I've got both basic Orion (came with a dob) plossls and nice Tele vue of the same FL to compare. I think this represents most of the range of quality, except maybe the cheapest of things.

The difference is pretty meaningful on bright objects like solar viewing and the moon, but to tell you the truth if I'm not rapidly switching between for comparison purposes the difference isn't even that noticable. It's a wide field eyepiece that isn't pushing the limits of any scope.

At some point you may find yourself wanting premium things, but if you're not there I wouldn't sweat it. Maybe point that money at a different gap in your eyepiece collection?

[vtornado]

Coating always increase scattering. It's a trade-off between transmission and scattering. Super-critical applications e.g. involving lasers use uncoated optics to minimize scattering. "Multi-coating" although real is more of an advertising buzz-phrase that a real performance issue, Most eyepieces are sold by the buzz, not actual performance.

 

-drl

If coatings increase scattering, what happens to the light that hits the coatings and is not transmitted?  I assume this is back scattered?  I have read that multi coatings that are not properly applied may result in worse performance than expertly applied single coatings.  Does roughness come into play?  Also we are talking about differences between $20.00 and $50.00 eyepieces in the Original posters case.

[sw196060]

The back scattered light is sent to the manufacturer.
For a fee they will send it to you via the cloud.