24 replies to this topic

[gemini1]

People,

 

I have one little question.

 

How do the Pentax XW SMC do with F-10?

 

Come to think of it, I have an F- 6.3, too.

 

Dean 

[MrsM75]

Follow this thread, as I want to get one Pentax XW myself. But it is expensive $296 an eyepiece, with tax it $310 price here in USA I mean.

 

So I'm still holding back, but tempted to get one.

Edited by MrsM75, 18 May 2025 - 08:16 PM.

[Dave Mitsky]

The Pentax SMC XW line will perform very well at either focal ratio.  I use a 7mm Pentax SMC XW with my 6" Celestron NexStar Evolution SCT from time to time at f/6.3 and f/10 with good results.

[gemini1]

Dave,

 

No edge problems at F-10?

 

Dean

[Procyon]

Excellent at F/10, one of the best eyepieces ever made, especially 40, 30, 10, 7, 5, 3.5

Type/AFOV/Center Spot Size/Zone Spot Size/Edge Spot Size
Diffr = Best, Under 10 = Great

Pentax XW 40 68 < 3 8 18 Ast.,FC +10%
Pentax XW 30 68 < 3 7 12 Ast.,FC +10%
Pentax XW 20 70 <4 7 23 Ast.,FC +8%
Pentax XW 14 69.4 Diffr 8 15 FC, CA 4%
Pentax XW 10 68.4 Diffr 4 5 Ast. 4%
Pentax XW 7 69.3 Diffr 8 15 FC,CA 8%
Pentax XW 5 69.5 Diffr 8 10 CA,FC 7%
Pentax XW 3.5 68.5 Diffr Diffr 8 CA 10%

10mm sample by Ernest:

Conclusions and recommendations
A practically flawless premium design, quite large and moderately heavy eyepiece. Closer to the edge of the field of view it blurs a little in extremely fast instruments. Otherwise - a contrast image with minimal manifestations of glare or light scattering. Convenient eye relief. I recommend it with a clear conscience and without reservations, both for observing deep space objects in fast telescopes, and for the Moon/planets in "slow" telescopes.

7mm Sample:

Conclusions and recommendations
The eyepiece is excellent! If it were not for the blue "snot" towards the center from bright stars, the image across the field of view could be considered very good. But I saw approximately the same manifestation of chromatic aberration in the only Delos that I tested. On dim stars, this chromatic aberration is practically unnoticeable and it certainly does not affect the visible contrast of the image. Barely noticeable curvature of the field of view is the only significant defect of the aberration calculation. In the central zone, the image, even with a high-aperture telescope objective, is spoiled only by defects in the optics of the eye. The eyepiece has exceptional quality of anti-reflective coatings on the lens surfaces - glare is very dim, there are no focused glare. Good blackening of the inner surfaces. The ergonomics of the eyecup are very convenient - observations with this eyepiece are comfortable.

If you have the means to buy this eyepiece (as a planetary-lunar one), you should seriously consider this option. Especially if you plan to use it with a not very fast telescope that has hourly tracking. The only real alternative to this eyepiece is the Delos from Teleview with a focal length of 8 or 6 mm. Delos with its better correction of field aberrations is more appropriate in especially fast telescopes such as Newtonians together with a coma corrector. The 7 mm Pentax XW with excellent coating and quality of aberration correction in the center of the field of view makes more sense to use in less fast apochromats and classic Schmidt-Cassegrains.

https://astro--talks...sch=http#p41709

Edited by Procyon, 19 May 2025 - 12:25 AM.

[scotsman328i]

Excellent at F/10, one of the best eyepieces ever made, especially 30, 10, 7, 5, 3.5

 

Type/AFOV/Center Spot Size/Zone Spot Size/Edge Spot Size

Diffr = Best, Under 10 = Great

 

Pentax XW 40 68  < 3 8 18 Ast.,FC +10%
Pentax XW 30 68  < 3 7 12 Ast.,FC +10%
Pentax XW 20 70  <4 7 23 Ast.,FC +8%
Pentax XW 14 69.4 Diffr 8 15 FC, CA 4%

Pentax XW 10 68.4 Diffr 4 5 Ast. 4%

Pentax XW 7 69.3  Diffr 8 15 FC,CA 8%
Pentax XW 5 69.5 Diffr 8 10 CA,FC 7%
Pentax XW 3.5 68.5  Diffr Diffr 8 CA 10%

 

10mm sample by Ernest:

 

Conclusions and recommendations

A practically flawless premium design, quite large and moderately heavy eyepiece. Closer to the edge of the field of view it blurs a little in extremely fast instruments. Otherwise - a contrast image with minimal manifestations of glare or light scattering. Convenient eye relief. I recommend it with a clear conscience and without reservations, both for observing deep space objects in fast telescopes, and for the Moon/planets in "slow" telescopes.

 

7mm Sample:

 

Conclusions and recommendations

The eyepiece is excellent! If it were not for the blue "snot" towards the center from bright stars, the image across the field of view could be considered very good. But I saw approximately the same manifestation of chromatic aberration in the only Delos that I tested. On dim stars, this chromatic aberration is practically unnoticeable and it certainly does not affect the visible contrast of the image. Barely noticeable curvature of the field of view is the only significant defect of the aberration calculation. In the central zone, the image, even with a high-aperture telescope objective, is spoiled only by defects in the optics of the eye. The eyepiece has exceptional quality of anti-reflective coatings on the lens surfaces - glare is very dim, there are no focused glare. Good blackening of the inner surfaces. The ergonomics of the eyecup are very convenient - observations with this eyepiece are comfortable.

 

If you have the means to buy this eyepiece (as a planetary-lunar one), you should seriously consider this option. Especially if you plan to use it with a not very fast telescope that has hourly tracking. The only real alternative to this eyepiece is the Delos from Teleview with a focal length of 8 or 6 mm. Delos with its better correction of field aberrations is more appropriate in especially fast telescopes such as Newtonians together with a coma corrector. The 7 mm Pentax XW with excellent coating and quality of aberration correction in the center of the field of view makes more sense to use in less fast apochromats and classic Schmidt-Cassegrains.

 

https://astro--talks...sch=http#p41709

Thanks for sharing, Pro. Great information and very informative!  I own the Pentax 7XW and Ernest is dead on-par with his recommendations for it. It’s fantastic in both my f/8.6 Televue 102 and f/6.3 Televue 76. 

Edited by scotsman328i, 19 May 2025 - 12:12 AM.

[Procyon]

Thanks for sharing, Pro. Great information and very informative! I own the Pentax 7XW and Ernest is dead on-par with his recommendations for it. It’s fantastic in both my f/8.6 Televue 102 and f/6.3 Televue 76.

Welcome, same here, have the 10 & 7 now, for the 2nd time, feel the same way, selling them away should be synonymous to regret. Ernest is a tough reviewer, so if it he's pleased, that's a good sign. Even with some ep's he's lukewarm on can still make for great eyepieces lol.

Edited by Procyon, 19 May 2025 - 12:30 AM.

[PKDfan]

How do they do ?

Well at F/6.45 the three i have are almost perfect to the edge with 16.5XW really special correction. 40XW and 30XW are worth every accolade they've earned but the new 85degree XW is astonishing.

I've only tested 30XW at F/9 and very similiar performance. Did briefly have 3.5XW too and Ernest tests it as Spectacular performance diffraction limited at F/4. Sharp sharp but i thought contrast wasn't quite as snappy.

My opinion is they're money very well spent...at least for my scopes ratios which aren't blazing fast.

40XW surprised me with very tiny stars across the field. Very clear views that engage you despite less than 70degrees for 40mm & 30mm.


Lance
CSS

[scotsman328i]

Welcome, same here, have the 10 & 7 now, for the 2nd time, feel the same way, selling them away should be synonymous to regret. Ernest is a tough reviewer, so if it he's pleased, that's a good sign. Even with some ep's he's lukewarm on can still make for great eyepieces lol.

Yeah Man, I’ve been reading further reviews just now by him on the Nikon NAV-SWs, Televue and Pentax EPs. I also have the Pentax 3.5XW, 30XW-R and 40XW-R that Earnest highly recommends. Earnest breaks it all down into nuts and bolts to explain every minuscule detail you wanted to know and why he rates stuff the way he does. Pretty awesome!

[scotsman328i]

How do they do ?

Well at F/6.45 the three i have are almost perfect to the edge with 16.5XW really special correction. 40XW and 30XW are worth every accolade they've earned but the new 85degree XW is astonishing.

I've only tested 30XW at F/9 and very similiar performance. Did briefly have 3.5XW too and Ernest tests it as Spectacular performance diffraction limited at F/4. Sharp sharp but i thought contrast wasn't quite as snappy.

My opinion is they're money very well spent...at least for my scopes ratios which aren't blazing fast.

40XW surprised me with very tiny stars across the field. Very clear views that engage you despite less than 70degrees for 40mm & 30mm.


Lance
CSS

Totally nailed it here, Lance. Couldn’t have said it better. I also own the XWs 40, 30, 7 and 3.5. All of them are excellent. IMHO I think their use of Lanthanum glass really makes a difference.

 

https://www.clzoptic...um-crown-glass/

Edited by scotsman328i, 19 May 2025 - 01:25 AM.

[25585]

Fine to F5. 

[PKDfan]

Totally nailed it here, Lance. Couldn’t have said it better. I also own the XWs 40, 30, 7 and 3.5. All of them are excellent. IMHO I think their use of Lanthanum glass really makes a difference.

https://www.clzoptic...um-crown-glass/

Thanks very much scotsman328i for the nice sentiment ! !

I'll share some further insights to my path and how & Why i've chosen what i have and how those things have actually performed.

A rather longer post on a cloudy night.

Lanthanum elements in my experiences does Much different things to the field of view depending -i guess- upon the thickness of the lense and maybe where in the eyepiece layout its located plus obviously the number of them. Does lanthanum itself have multiple tints depending upon who makes it ??

Is it in a thin meniscus lense or in a big cemented doublet ?

For example 17.3Delos has the whitest stars i've ever seen and M42 main nebula was immediately greenish. I'd never ever have thought lanthanum, only ED.

However adding a 5X PowerMate upon the moon starts to show a slight yellow tint bias thats utterly invisible without PM-- maybe its the PM adding a slight tint then ? IDK for sure yet, need to use it with a longer Plössl to know for sure.

I cannot see any tint bias within any of the huge XW glass whatsoever.

Morpheus is a totally different visual experience-- especially going from 9Morpheus to 8Plössl.

With two lanthanum elements the three shortest Morphii display three different degrees of tint warmth and its a slight colour bias that my eyes highly enjoy. A deeper colour- however you define that ?!? Scatter is controlled very well and despite a glaring issue with 4.5M its on-axis sharpness is from 9M excellent to astonishing.

9M<6.5M<4.5M.

The crystaline clarity of 4.5M is my GnG experience par excellence and easily add a 2X Barlow for 166X and most of the moon is visible.

I've certainly warmed up to them. Lol.

Not quite at a T2 Nagler level love but i'd cry if one got destroyed. Easily cleaning them recently the glass disappeared and brought back those best view nights when extraordinairy things happened with them.


I've come to the conclusion that lanthanum is wildly different in tonal honesty between manufacturers, and even within a series, you simply cannot assume a certain thing just because its got a lanthanum label on it, except maybe for getting very high quality views.

My first Morpheus 6.5mm seems to be the one with the most bias and three years with the 100ED (135X) was just enough power to witness very fine details.

Lunar views with it have a certain joie de vivre, an exuberance of information, so Morphii with varying levels of warmth and versus the cold clinical ultra sharp Plössl views i sense a greater immersion depth thats no doubt created by nearly 80degrees of pinsharpness (nearly to the edge of the FS). Yet their ultimate sharpness is a....micron off. Plössls central 50% at F/6.45 knocks Morphii out of top spot.


However the transition to the same power Baader zoom view is a tint transition knockout punch...a side by side view would easily show Morpheus & Mark IV different tint renders.

In actuality its more subtle to the eye but certainly obvious, but not overwhelmingly so, so take my tint rendition perceptions with a small grain of salt.

Atmosphere conditions can obfuscate or overwhelm these nuances for the most part.

A 2X Barlow with 6.5Morpheus gave me a Mars 270X view that was better than most any photo i've ever seen and i credit lanthanum & ED glass elements for the 'hot' view i got. Hellas sunkissed orange 'eye' in your face, a weak yellow surface and the colours of brighter & darker sands, a Wicked south pole Whiteness Spear that was like a minus 10 icicle trying to lance my fovea centralis that i needed to dodge and weave around to grasp the deep dark green blues of an etched in myriad cells Syrtis Major which finally TOLD ME my 100ED's Quality state in no uncertain terms.

I struggle to understand if a colder maybe even sharper Plössl view at that moment would be better ? I highly doubt it.

Cleaning it for the first time (a nerve wracking 40minutes) and looking at the ultra simple cell & beauty ring aside, is a work of art without screws to mar its smooth surfaces and like holding a brick.

The glass upon very close inspection with bright glaring illuminations is like looking at a crystal.


Without a reference White you don't realy know what colour equilibrium your apochromatic objective translates.

And ignorance is bliss because the mind weapon is amazing at bringing normality to an image colour cast within a very short time.

So,
Is it a pure and equal transmission of colours upon first focus ? That grabs you by its mirroring of reality ?

And Critically does it immediately provoke INVOLVEMENT within the space when critically focused ?

A tint then can be neglible if not wholly irrelevant.

And Gosh the hardest thing to find when you find (unexpectedly) have REFERENCE level optics is to acquire eyepieces that can harness all of that horsepower and i can unequivocabley state a Plössl would have made my exploration to UNDERSTAND intimately those things contained with the objective itself in much less time.

Its very Hard to describe how brilliant sharpness compares to exquisite level sharpness as thats basically what it comes down to.
Its not like things will be seen with one and not the other, it might take a higher power to detect it with a less composed eyepiece but most all the same details just BETTER delineated will be there-- IF you can get to a 'brilliant' level of it.

A critical threshold that even the very cheapest of eyepieces can reach IF your ratio is right AND your optical Quality is sufficient.

You DON'T NEED the expensive eyepieces whatsoever.

*
The brief space clear stillness conditions i encountered of course helped a wee little bit.
*

IMO lanthanum loaded eyepieces CANNOT be pigeon-holed as being a certain way...warm or cold say-- by just reading that they contain it. Maybe it does change a very tiny colour temperature from a nominal view, then again, maybe not.

The 17.3Delos view was especially magical/intriguing with its ultra white views.
Terrestrially the long Delos is wicked in its authority and can consume you entirely as you scan within its field for data so the white differences it sees are especialy note worthy and honestly was the sole reason i bought it. Well that and its brutal sharpness and ease of exit pupil.

My mind perceives it as a purity of essence that immediately consumes me and my location awareness.

What i hope the virtual image to always contain. A real 3D space.

M42 stunned me with its 23X definition and delineation and 5X moon was rille city but with a slightest of a yellow cast.

The immediate difference within the lunar Morpheus to a Plössl view is a sudden transission to the more normal variety of greys eg. sinus aestuum ravines very dark charcoal like and all of mare serentatatis unique textures along its perimeter and what looked like more scatter than contrast in Morpheus at mare fecundatatis southern flank gets etched into micro craterlet rays.

The Things in the Plössl field become so sharp ... seems to bite you when you finally get to critical sharpness. Raypaths become a bewildering variety of traces.

SuperFine optics and SMC Pentax (Ricoh now) is a marriage made in heaven and gosh bring an F/10 with smooth optics you'll simply fall into their eyepieces views.

Right tools for the job at hand and finally 'sometimes' when you've got good enough you don't really require great, its a very thin dividing line, and further my conviction is is to acccept less than great when an eyepiece offers a unique facet to its optical prescription repertoire.

A sacrifice in AFOV for higher contrasts or sharpness. And Vice versa.

A test of a 25mm uncoated Huygens Mitzenzwey with 5X PM told me highly saturated Jupiter contrasts was worth the tiny glass inclusioned view at practically zero costs.

F/32.25+ can do wonders.

So some observing thoughts that'll maybe bring an ah ha moment to you.

Thanks very kindly for sticking to the end.


Clear Steady Skies
Lance

[scotsman328i]

Thanks very much scotsman328i for the nice sentiment ! !

I'll share some further insights to my path and how & Why i've chosen what i have and how those things have actually performed.

A rather longer post on a cloudy night.

Lanthanum elements in my experiences does Much different things to the field of view depending -i guess- upon the thickness of the lense and maybe where in the eyepiece layout its located plus obviously the number of them. Does lanthanum itself have multiple tints depending upon who makes it ??

Is it in a thin meniscus lense or in a big cemented doublet ?

For example 17.3Delos has the whitest stars i've ever seen and M42 main nebula was immediately greenish. I'd never ever have thought lanthanum, only ED.

However adding a 5X PowerMate upon the moon starts to show a slight yellow tint bias thats utterly invisible without PM-- maybe its the PM adding a slight tint then ? IDK for sure yet, need to use it with a longer Plössl to know for sure.

I cannot see any tint bias within any of the huge XW glass whatsoever.

Morpheus is a totally different visual experience-- especially going from 9Morpheus to 8Plössl.

With two lanthanum elements the three shortest Morphii display three different degrees of tint warmth and its a slight colour bias that my eyes highly enjoy. A deeper colour- however you define that ?!? Scatter is controlled very well and despite a glaring issue with 4.5M its on-axis sharpness is from 9M excellent to astonishing.

9M<6.5M<4.5M.

The crystaline clarity of 4.5M is my GnG experience par excellence and easily add a 2X Barlow for 166X and most of the moon is visible.

I've certainly warmed up to them. Lol.

Not quite at a T2 Nagler level love but i'd cry if one got destroyed. Easily cleaning them recently the glass disappeared and brought back those best view nights when extraordinairy things happened with them.


I've come to the conclusion that lanthanum is wildly different in tonal honesty between manufacturers, and even within a series, you simply cannot assume a certain thing just because its got a lanthanum label on it, except maybe for getting very high quality views.

My first Morpheus 6.5mm seems to be the one with the most bias and three years with the 100ED (135X) was just enough power to witness very fine details.

Lunar views with it have a certain joie de vivre, an exuberance of information, so Morphii with varying levels of warmth and versus the cold clinical ultra sharp Plössl views i sense a greater immersion depth thats no doubt created by nearly 80degrees of pinsharpness (nearly to the edge of the FS). Yet their ultimate sharpness is a....micron off. Plössls central 50% at F/6.45 knocks Morphii out of top spot.


However the transition to the same power Baader zoom view is a tint transition knockout punch...a side by side view would easily show Morpheus & Mark IV different tint renders.

In actuality its more subtle to the eye but certainly obvious, but not overwhelmingly so, so take my tint rendition perceptions with a small grain of salt.

Atmosphere conditions can obfuscate or overwhelm these nuances for the most part.

A 2X Barlow with 6.5Morpheus gave me a Mars 270X view that was better than most any photo i've ever seen and i credit lanthanum & ED glass elements for the 'hot' view i got. Hellas sunkissed orange 'eye' in your face, a weak yellow surface and the colours of brighter & darker sands, a Wicked south pole Whiteness Spear that was like a minus 10 icicle trying to lance my fovea centralis that i needed to dodge and weave around to grasp the deep dark green blues of an etched in myriad cells Syrtis Major which finally TOLD ME my 100ED's Quality state in no uncertain terms.

I struggle to understand if a colder maybe even sharper Plössl view at that moment would be better ? I highly doubt it.

Cleaning it for the first time (a nerve wracking 40minutes) and looking at the ultra simple cell & beauty ring aside, is a work of art without screws to mar its smooth surfaces and like holding a brick.

The glass upon very close inspection with bright glaring illuminations is like looking at a crystal.


Without a reference White you don't realy know what colour equilibrium your apochromatic objective translates.

And ignorance is bliss because the mind weapon is amazing at bringing normality to an image colour cast within a very short time.

So,
Is it a pure and equal transmission of colours upon first focus ? That grabs you by its mirroring of reality ?

And Critically does it immediately provoke INVOLVEMENT within the space when critically focused ?

A tint then can be neglible if not wholly irrelevant.

And Gosh the hardest thing to find when you find (unexpectedly) have REFERENCE level optics is to acquire eyepieces that can harness all of that horsepower and i can unequivocabley state a Plössl would have made my exploration to UNDERSTAND intimately those things contained with the objective itself in much less time.

Its very Hard to describe how brilliant sharpness compares to exquisite level sharpness as thats basically what it comes down to.
Its not like things will be seen with one and not the other, it might take a higher power to detect it with a less composed eyepiece but most all the same details just BETTER delineated will be there-- IF you can get to a 'brilliant' level of it.

A critical threshold that even the very cheapest of eyepieces can reach IF your ratio is right AND your optical Quality is sufficient.

You DON'T NEED the expensive eyepieces whatsoever.

*
The brief space clear stillness conditions i encountered of course helped a wee little bit.
*

IMO lanthanum loaded eyepieces CANNOT be pigeon-holed as being a certain way...warm or cold say-- by just reading that they contain it. Maybe it does change a very tiny colour temperature from a nominal view, then again, maybe not.

The 17.3Delos view was especially magical/intriguing with its ultra white views.
Terrestrially the long Delos is wicked in its authority and can consume you entirely as you scan within its field for data so the white differences it sees are especialy note worthy and honestly was the sole reason i bought it. Well that and its brutal sharpness and ease of exit pupil.

My mind perceives it as a purity of essence that immediately consumes me and my location awareness.

What i hope the virtual image to always contain. A real 3D space.

M42 stunned me with its 23X definition and delineation and 5X moon was rille city but with a slightest of a yellow cast.

The immediate difference within the lunar Morpheus to a Plössl view is a sudden transission to the more normal variety of greys eg. sinus aestuum ravines very dark charcoal like and all of mare serentatatis unique textures along its perimeter and what looked like more scatter than contrast in Morpheus at mare fecundatatis southern flank gets etched into micro craterlet rays.

The Things in the Plössl field become so sharp ... seems to bite you when you finally get to critical sharpness. Raypaths become a bewildering variety of traces.

SuperFine optics and SMC Pentax (Ricoh now) is a marriage made in heaven and gosh bring an F/10 with smooth optics you'll simply fall into their eyepieces views.

Right tools for the job at hand and finally 'sometimes' when you've got good enough you don't really require great, its a very thin dividing line, and further my conviction is is to acccept less than great when an eyepiece offers a unique facet to its optical prescription repertoire.

A sacrifice in AFOV for higher contrasts or sharpness. And Vice versa.

A test of a 25mm uncoated Huygens Mitzenzwey with 5X PM told me highly saturated Jupiter contrasts was worth the tiny glass inclusioned view at practically zero costs.

F/32.25+ can do wonders.

So some observing thoughts that'll maybe bring an ah ha moment to you.

Thanks very kindly for sticking to the end.


Clear Steady Skies
Lance

Thanks so much Lance for the very in-depth write up. I definitely agree, Lanthanum is only as good as the magic a manufacturer works with it. Somehow, Pentax does amazing things with Lanthanum to create such fine oculars. I remember years ago, my first Lanthanum ocular I ever owned was an Orion Lanthanum ocular. That was soon followed by another Vixen Lanthanum one. I’m sure there have been earlier designs with Lanthanum, but for my experiences those two were kinda the pioneers of first time experiences with Lanthanum and I, and was always very impressed by the contrast, clarity and brightness presented by them. 
    Years have passed and more technologies have presented and I still find Lanthanum, when used correctly in ocular designs, a phenomenal performer. I have found my Pentax XWs present some of the finest views on Lunar details and Planetary details. The Pentax 7 and 3.5XWs to include my Nikon 5NAV SW have moved me on from Plossl and Ortho designs for low power viewing. Some of that due to the longer ER, but the majority of it due to the overall image presented of details that are so sharp, bright and contrasty. Some details have been very closely compared to have the Pentax win by thin margins over some of my Baader Orthos, other details by a wide margin.
   Overall, I can’t recommend Pentax XW Series oculars enough if someone is a discerning observer that truly demands exquisite views of brighter Solar System objects. They truly excel in my Televue 102 and Televue 76 refractors, but are absolutely fantastic in my 8” Dob also. 
  Thanks again Lance for the great info!

     Don. 

Edited by scotsman328i, 19 May 2025 - 06:58 AM.

[scotsman328i]

Fine to F5. 

Yes, I read that from Ernest also. Anything lower than f/5 or so, they start getting a little sloppy on the edges. Lowest I have is an f/5.9 Orion XT8 Plus. Both Televues are f/6.3 and f/8.6. 

[SeattleScott]

The 20 would be the one to question. A spot size of 23 at the edge at F10 isn’t bad, but perhaps not as good as one expects at this price point. And it could legitimately struggle at F6.3.

But the others should be fine at F10 or F6.3, and you get the central contrast and cool tone the XWs are known for.

[Albie]

I have the Pentax XW 5, 7 ,10 , 14 , 20 and 30mm ep's .  I use them in a Skywatcher 250P Classic dobsonian f/4.7. I am happy with their performance with the Skywatcher dob , they do get a bit soft at the edge but that's to be expected at f/4.7 and it's really not that bad for me , ymmv . Very comfortable eyepieces with or without glasses .

 

 

 

Attached Thumbnails

• 

[Mike W]

Televue eyepieces tested to F/4 if needed.

 

https://www.bing.com...994&FORM=VRDGAR

Edited by Mike W, 19 May 2025 - 02:58 PM.

[Procyon]

Televue eyepieces tested to F/4 if needed.

LOL : )

 

[scotsman328i]

I have the Pentax XW 5, 7 ,10 , 14 , 20 and 30mm ep's .  I use them in a Skywatcher 250P Classic dobsonian f/4.7. I am happy with their performance with the Skywatcher dob , they do get a bit soft at the edge but that's to be expected at f/4.7 and it's really not that bad for me , ymmv . Very comfortable eyepieces with or without glasses .

Nice Albie! Don’t you have a Paracorr or other CC to clean those edges up, Bro? 

Edited by scotsman328i, 19 May 2025 - 03:58 PM.

[scotsman328i]

LOL : )

 

Procyon 

[gemini1]

Scotsman, Albie,

 

Would a Paracorr clean up the edge of a Meade F - 6.3 SCT?

 

Dean

[Albie]

Nice Albie! Don’t you have a Paracorr or other CC to clean those edges up, Bro? 

I have yet to buy a paracorr . For now I am fine with what I am seeing with my ep's but there is still a possibility that I will buy one in the fall of 2025 .

[SeattleScott]

Scotsman, Albie,

Would a Paracorr clean up the edge of a Meade F - 6.3 SCT?

Dean

Certainly not what a Paracorr was designed for. Although some use it at F6 in Dobs. Honestly not sure it would even fit. Probably can’t go in diagonal. Putting it before diagonal could hit reducer, or cause clearance issues with base, or just mess up how the Paracorr works because of so much space between Paracorr and eyepiece. I really doubt it would work. Fun to think about though.

[scotsman328i]

Scotsman, Albie,

 

Would a Paracorr clean up the edge of a Meade F - 6.3 SCT?

 

Dean

Dean, Parabola correctors (or coma correctors) are needed for Newtonian optics faster than f/5. They are between $150 and $500, depending on the quality and brand. I doubt you would benefit much, if at all from it, at f/6.3.

[scotsman328i]

I have yet to buy a paracorr . For now I am fine with what I am seeing with my ep's but there is still a possibility that I will buy one in the fall of 2025 .

Cool, I gotcha.