Jump to content

Stargazers Lounge Uses Cookies

Like most websites, SGL uses cookies in order to deliver a secure, personalised service, to provide social media functions and to analyse our traffic. Continued use of SGL indicates your acceptance of our cookie policy.

sgl_imaging_challenge_banner_solar_25_winners.thumb.jpg.fe4e711c64054f3c9486c752d0bcd6f2.jpg

Sign in to follow this  
Mike_S

20-25mm Televue Panoptic perhaps?

Recommended Posts

A year or two back, my friends and I compared the 24mm Panoptic with a 24mm Hyperion, and found that in an F7.4 refractor and in an F6.9 refractor the Hyperion had the sharper edge of field, and was noticeably more comfortable to use than the 24mm Pan'.  Just saying! :icon_scratch:

  • Like 1

Share this post


Link to post
Share on other sites
35 minutes ago, mikeDnight said:

A year or two back, my friends and I compared the 24mm Panoptic with a 24mm Hyperion, and found that in an F7.4 refractor and in an F6.9 refractor the Hyperion had the sharper edge of field, and was noticeably more comfortable to use than the 24mm Pan'.  Just saying! :icon_scratch:

I'm a little surprised by that Mike. I like the Hyperions but sharp to the edge once the focal ratio drops below F/8 is not a strength of theirs IMHO. I found the ES 24 / 68 my current Pan 24, the Vixen 22 / 65 LVW and even the Maxvision 24 / 68 sharper across the field in all the scopes I've tried them in. I don't think I could ever recommend Hyperions (the fixed focal length ones anyway) for an F/4.7 newtonian like the OP has :icon_scratch:

For comfort I can see that some would prefer the larger eye lens and longer eye relief of the Hyperion 24 though. Maybe the latest Hyperions have improved their fast scope edge correction ?

The more we (all of us, not just you and I !) discuss eyepieces over the years, the more I've become convinced that personal preferences have a huge influence on what we find we prefer. Just as well there are so many choices on the market, or perhaps that is why there are so many ? :icon_biggrin:

 

  • Like 1

Share this post


Link to post
Share on other sites
1 hour ago, John said:

Is that the OVL Myriad MWA 100 20mm ?

 

It’s the Sky Watcher Myriad MWA 100 degrees 20mm. Is that one still okay or a different version?

Share this post


Link to post
Share on other sites
1 minute ago, MSammon said:

It’s the Sky Watcher Myriad MWA 100 degrees 20mm. Is that one still okay or a different version?

Thats the one that I thought it was ! :icon_biggrin:

I reviewed it a while back along with some others in the Myriad range. Nice eyepiece - congratulations !

  • Thanks 1

Share this post


Link to post
Share on other sites
8 minutes ago, John said:

I'm a little surprised by that Mike. I like the Hyperions but sharp to the edge once the focal ratio drops below F/8 is not a strength of their IMHO. I found the ES 24 / 68 my current Pan 24, the Vixen 22 / 65 LVW and even the Maxvision 24 / 68 sharper across the field in all the scopes I've tried them in.

For comfort I can see that some would prefer the larger eye lens and longer eye relief of the Hyperion 24 though. Maybe the latest Hyperions have improved their fast scope edge correction ?

The more we (all of us, not just you and I !) discuss eyepieces over the years, the more I've become convinced that personal preferences have a huge influence on what we find we prefer. Just as well there are so many choices on the market, or perhaps that is why there are so many ? :icon_biggrin:

 

It came as a surprise to me too John. The 24mm Pan belonged to my friend Derek who uses it in his Sky 90, and he's very happy with it. The 24mm Hyperion belongs to paulastro, and with several rounds of observing with each eyepiece, all on the same night, I was much happier with the edge in the Hyperion. I think Paul felt the same, but nothing could ever budge Derek from his love affair with Televue. At the time I was looking to downsize my eyepieces from bulky designs to small bodied 1.25" types. I never did buy either the 24 Pan or the 24 Hyperion, in part I discarded the Hyperion because I think its quite ugly and if I'm going to go for an eyepiece of that physical size, I'd go for yet another 20mm XW.

It's funny, because the more I learn about eyepieces and telescopes, the less I actually seem to know at the end of it!  So it's probably wise to view most of my posts as little more than chirping, a bit like an annoying budgie. ?

  • Haha 3

Share this post


Link to post
Share on other sites
37 minutes ago, John said:

Maybe the latest Hyperions have improved their fast scope edge correction ?

Well, there are two versions of the 21mm Hyperion, so it might be possible the 24mm was redesigned.

  • Like 2

Share this post


Link to post
Share on other sites

I always enjoy your "chirping" Mike :smiley:

  • Like 1

Share this post


Link to post
Share on other sites
2 hours ago, Louis D said:

I'm looking forward to hearing about how you get on with that eyepiece.  Make sure to report back here on it since there aren't a lot of posts about it.

MSammon, congrats on your eyepiece.

I'll be interested to hear too. I addressed this in a different way in a scope the same as yours 10 inch F4.7.  I have a Maxvision 28mm 68 degrees, this covers  the same amount of sky as a ES 24mm 82  degrees ( roughly, top of my head, i think this is correct) . 

I do not wish to bias your opinion on the pros and cons of each however and see how you get on. I find it interesting that people often pick the wider FOV, as opposed to the net result of a longer focal length eyepiece with smaller FOV showing the same amount of sky.   

Share this post


Link to post
Share on other sites

There is also the APM uff 24mm, which I never tried, but if this is like the 30mm, it certainly deserves a consideration.

Share this post


Link to post
Share on other sites
1 hour ago, AlexB67 said:

.... I find it interesting that people often pick the wider FOV, as opposed to the net result of a longer focal length eyepiece with smaller FOV showing the same amount of sky.   

I think the resulting exit pupil is part of the equation when fast scopes are involved.

  • Like 1

Share this post


Link to post
Share on other sites
9 minutes ago, John said:

I think the resulting exit pupil is part of the equation when fast scopes are involved.

I agree, but there other factors too, I wouldn't say one is an incorrect or correct choice, depending on the situation, and what you want, but I didn't want to bias the OP either way. I think there are pros and cons one  can argue for in either direction in a fast scope.

Share this post


Link to post
Share on other sites

It looks like I'm building up a range of Myriads and Pentax XW's. Although part of me feels I could've just gone for a complete set of ES 82 degrees and benefitted from the parfocul feature. I bet I'm going to try some ES at some point. 
Sky looking clear tonight so I'm finally going to be able to compare my 5mm Myriad and 5mm Pentax XW. Need to decide which to keep and which to sell really. Ended up buying both as I couldn't decide lol. 

Share this post


Link to post
Share on other sites
1 hour ago, Piero said:

There is also the APM uff 24mm, which I never tried, but if this is like the 30mm, it certainly deserves a consideration.

It's not quite as well corrected at the edge as the 30mm at f/6, but it is quite good.  It also has a 27.5mm effective field stop thanks to a bit of vignetting at the field stop.  It is tiny bit wider than a 32mm GSO Plossl.  Even then, it depends on whether or not there's a 2" barlow or coma corrector in use ahead of it.  I vaguely recall one or both sharpen up the field stop.

I haven't had the opportunity to compare it to the typical 68 degree SWA offerings because none of them have enough eye relief for my glasses.  I'm still developing my opinion of the 24mm UFF, so that's all I'll say about it at this time.

Share this post


Link to post
Share on other sites
39 minutes ago, AlexB67 said:

I agree, but there other factors too, I wouldn't say one is an incorrect or correct choice, depending on the situation, and what you want, but I didn't want to bias the OP either way. I think there are pros and cons one  can argue for in either direction in a fast scope.

Yes there are pros and cons of both ways. I've gone for what works best under my skies which tend to be short focal lengths with a very fields of view and those create a darker background sky and make faint DSO's that little bit easier to pick out. I have a choice of 21mm / 100 degrees, 31mm / 82 degrees and 40mm / 68 degrees. The 21 / 100 sees a lot more action in my 12 inch F/5.3 dob :smiley:

But thats just my take on it - others may well find a different approach works better for them :smiley:

 

Share this post


Link to post
Share on other sites

Why do people tend to go for narrower field of view for their planetary eyepieces like 70 degrees when the same focul length is available in 82 or 100 degrees? Is it the quality of the view?

Share this post


Link to post
Share on other sites
31 minutes ago, MSammon said:

Why do people tend to go for narrower field of view for their planetary eyepieces like 70 degrees when the same focul length is available in 82 or 100 degrees? Is it the quality of the view?

82° or 100° are more expensive and often have limited eye relief at higher mags. Take the Delos range; as good (or better) sharpness / contrast etc as the Ethos range at 50% of the price. Also, for most high mag targets such as Planets, doubles, globs etc, you don’t need a wide field.

Paul

  • Thanks 1

Share this post


Link to post
Share on other sites

I’ve been going for wider field because of nudging but I may find not that’s so necessary. Haven’t tried my wide fields yet. Any night now as soon as the skies clear :)

Share this post


Link to post
Share on other sites

I use 100 degree eyepieces at high powers as well. It's not necessary of course but with all my scopes being undriven I find it is a bit more relaxing, nudging less often. The optical quality of todays 100 degree offerings is surprisingly good when used as high power tools.

I've also found that I need less eyepieces when the field of view is very large. With my 100's I find that 4 eyepieces (21, 13, 8 and 6mm) are all I need most of the time with my 12 inch dobsonian.

 

  • Like 1

Share this post


Link to post
Share on other sites
2 hours ago, MSammon said:

Why do people tend to go for narrower field of view for their planetary eyepieces like 70 degrees when the same focul length is available in 82 or 100 degrees? Is it the quality of the view?

It's generally felt among planetary observers that the greater number of elements found in complex wide angle eyepieces tends to have some drawbacks. Wide angle eyepieces do suffer from lateral colour which may potentially lead to a false colour rendition of a planet, such as increasing the yellow on Saturn. Some of the worst culprits in my experience are Nagler eyepieces which really show significant lateral colour. Pentax XW's however are purer and quite orthoscopic in nature, though they do have a measure of lateral colour they are superb planetary eyepieces. It's not a fault, just the nature of the beast!   The beauty of having a wider field when observing the planets, is that it allows longer for the planet to cross the field, and the observer more time to study the planetary disc before adjusting the controls of a manual mount.

Narrow fields and simple designs potentially offer greater clarity and higher definition, though at a cost. Eye relief and width of true field can be reduced significantly, which makes using them less easy on an undriven mount. Also, simpler eyepiece designs of high quality are just as expensive as the high quality wider field versions. Perhaps if you decide to specialize in lunar and planetary, or double star observing, then the narrower field, top end eyepieces, could pay off in good seeing conditions when used in a good telescope. 

Today, it seems wide field eyepieces are of very high quality, and their prices don't necessarily need to be high. Sky watcher Nirvana eyepieces are very impressive and sharp to the edge of the field. The 4mm 82° Nirvana for example makes an excellent planetary eyepiece at low cost, and in my experience keeps pace with some of the very best from TeleVue as far as sharpness and contrast. I have my personal preferences as far as the make of eyepiece goes, but I'm not overly bothered if its a wide or narrow field eyepiece I'm using, providing it renders a pure image. 

  • Like 2
  • Thanks 1

Share this post


Link to post
Share on other sites

Now that the cat is out of the bag so to speak I will elaborate a bit in addition to the great post above.  My other main reason for not using wide angle eyepieces is coma. For me if I went much wider than 70 degrees I would find it really bothersome, I don't mean it's like  an on/off switch with a hard value of course, but it gets worse the further off-center you go. 

I would really want a coma corrector for the ultra wide angle eyepieces in an f4.7 scope, it is extra gear I rather avoid, I am happy with the smaller views anyways,  as long as they good are sharp. For planetary viewing I find anything above 60 degrees plenty, I am quite used to nudging with a 40 degree ortho, though admit it can get a bit tedious at times. 

  • Like 3

Share this post


Link to post
Share on other sites
6 hours ago, MSammon said:

Why do people tend to go for narrower field of view for their planetary eyepieces like 70 degrees when the same focul length is available in 82 or 100 degrees? Is it the quality of the view?

For me, I have such bad astigmatism in my observing eye that I need to wear eyeglasses at the eyepiece.  As a result, I need 16mm to 20mm of usable eye relief to be able to fit my glasses in between my face and the eyepiece.  This necessitates a large eye lens which in turn requires large lenses below it.  This results in a big and heavy eyepiece.  As a result, I often make due with smaller AFOV eyepieces to ease balance or simply transportation of eyepieces.

  • Like 2

Share this post


Link to post
Share on other sites
8 hours ago, AlexB67 said:

Now that the cat is out of the bag so to speak I will elaborate a bit in addition to the great post above.  My other main reason for not using wide angle eyepieces is coma. For me if I went much wider than 70 degrees I would find it really bothersome, I don't mean it's like  an on/off switch with a hard value of course, but it gets worse the further off-center you go. 

I would really want a coma corrector for the ultra wide angle eyepieces in an f4.7 scope, it is extra gear I rather avoid, I am happy with the smaller views anyways,  as long as they good are sharp. For planetary viewing I find anything above 60 degrees plenty, I am quite used to nudging with a 40 degree ortho, though admit it can get a bit tedious at times. 

Good point!

I've had quite a selection of top end wide angle eyepieces over the years and the edge of field was always distorted even between F7 & F8. This kind of annoyed me, especially with the low power eyepieces, as this is where the wide field really comes into its own. I found the better edge sharpness and to some extent clarity, was more pleasing to me when using 52° and simpler yet good designs. I thought "why am I paying all that money for a wide field eyepiece, when the outer 20% of the field has a measure of distortion? It also became apparent that the true field wasn't necessarily that much smaller in narrower apparent fields than in some wide angles. I still have a couple of nice wide angle eyepieces but most of my current selection are five element and 52° and they are wonderful!

Share this post


Link to post
Share on other sites

When I'm testing eyepieces (usually to report on them here) one of my tests is to take a planet such as Jupiter or Saturn, and let it drift right across the field of view, until it dissapears behind the field stop. As well as changes in shape of the target object due to edge field distortions of one form or another, I look for any diminishment in resolution / sharpness of the features of the planet as it nears the field edge and also any changes to the tint of the target and any CA that may be introduced. I do the same with tight binary stars and the lunar surface and repeat the test a number of times. It's quite a revealing test.

One of the things that I like about my 6mm Ethos is how it handles the above tests. Even with my fastest scope (the F/5.3 dobsonian) a target like Saturn retains superb sharpness, definition, contrast and colour tint right across the field of view until it slips behind the field stop. The Ethos 6mm gives 265x with that scope so a pretty decent high power. If very expensive tools such as this can't achieve that, I would not hang onto them in a high power observing role. As Mike says, you want the field you have paid for to be as good a quality as possible right across the field or you might as well be using a narrower AFoV eyepiece.

 

 

  • Like 1

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Sign in to follow this  

  • Recently Browsing   0 members

    No registered users viewing this page.

×
×
  • Create New...

Important Information

By using this site, you agree to our Terms of Use.