24mm Panoptic

[Alma]

I've owned and sold dozens of eyepieces over the years - the 24mm Panoptic is the only one I wish I hadn't sold.

[Brian Nordstrom]

Hi again Joves  , I have the 19-22-24 and 27 Pans ( all 2nd hand off IIS ) and wont ever give them up , you are right cracking Gem's of an eyepiece , I just love mine .

Brian.

[pbsastro]

I am really hoping the Pans, specially the Pan 24, get phased out.

The pans are very outdated, with reported transmission levels below all other eyepieces.

All may be needed is a small update to the design. Naglers have so many types, why not a Pan type 2?

[pbsastro]

Here one very credible report about Pans transmission issues:

http://www.cloudynights.com/item.php?item_id=2729

[alan potts]

Panoptics outdated, can't agree with that one iota, in my books they are still superb eyepieces and I have a few to compare them with.

Alan.

[pbsastro]

Alan you didn’t comment specifically on the transmission issue.

Pans are not best for daytime because of strong pincushion distortion.

Pans long focal lengths places them less as planetary and more as deep-sky eyepieces.

For deep-sky, the most important factor is transmission. Most times transmission is ignored because transmission differences are small enough to not be noticeable. But according to some reports, the difference is quite noticeable. Enough for the author of the report above preferring the ES 24 although the Pan 24 being sharper off-xis.

Could you not detect any transmission difference between Pan 24, ES 24, Meade 24, or Tak 24?

Pedro

[John]

Alan you didn’t comment specifically on the transmission issue.

Pans are not best for daytime because of strong pincushion distortion.

Pans long focal lengths places them less as planetary and more as deep-sky eyepieces.

For deep-sky, the most important factor is transmission. Most times transmission is ignored because transmission differences are small enough to not be noticeable. But according to some reports, the difference is quite noticeable. Enough for the author of the report above preferring the ES 24 although the Pan 24 being sharper off-xis.

Could you not detect any transmission difference between Pan 24, ES 24, Meade 24, or Tak 24?

Pedro

Have you done such comparisons Pedro ?

If so, what were your findings ?

The figures I have found for Panoptic transmission vary between 90% and 93% depending on the model and it's age. The best eyepiece transmission figures seem to be around 96%-97% (eg: Baader Classic Ortho). So the difference could be a matter of as little as 3%-4% and I believe it's hard for us to detect differences of less than 10% visually so it's quite possible that the vast majority of observers would not notice the lesser transmission figure. They might however notice the off axis sharpness that the Panoptic delivers even in fast scopes.

I've owned the 19mm and 24mm Panoptics and thought them excellent eyepieces. At a star party last year it was a 24mm Panoptic that showed the Horsehead Nebula through a 16" scope with the help of an H-Beta filter and, as I'm sure you know, thats a tough target under any circumstances.

[pbsastro]

Have you done such comparisons Pedro ?

If so, what were your findings ?

The figures I have found for Panoptic transmission vary between 90% and 93% depending on the model and it's age. The best eyepiece transmission figures seem to be around 96%-97% (eg: Baader Classic Ortho). So the difference could be a matter of as little as 3%-4% and I believe it's hard for us to detect differences of less than 10% visually so it's quite possible that the vast majority of observers would not notice the lesser transmission figure. They might however notice the off axis sharpness that the Panoptic delivers even in fast scopes.

I've owned the 19mm and 24mm Panoptics and thought them excellent eyepieces. At a star party last year it was a 24mm Panoptic that showed the Horsehead Nebula through a 16" scope with the help of an H-Beta filter and, as I'm sure you know, thats a tough target under any circumstances.

No John, I did not do comparisions with Pans. My findings were the several reports from people who did comprehensive testing on them. The author of the report above is very credible. But others reports confirm the same transmission issue with the Pans.

I am now on the market for a pair of 1.25" wide-fields, and a pair of Pan24 would be the clear choice if it was not for the transmission issue I have been reading.

I am aware of those typical small diferences between eyepieces, and that those are not noticeable. That was what I said first in fact. How did you get the 90-93% numbers for the Pans? And which year are those Pans? In any case that is less than the 96% for the XWs: http://pentaxplus.jp/archives/tech/xo-xw/63.html

So if your numbers are true, there is place for improvement there for Televue.

However the difference on the report seems much bigger than 5%, to be so noticeable. Maybe a very old Pan was being used, more then 20 years for example, with very old coatings. And that brings my biggest doubt. Probably TV eyepieces have been evolving silently during 20 years, speciailly the coatings, so a new Pan may be much better than an old Pan.

In any case there are rumors that TV may be replacing the Pans very soon. So I will hold at leat until next weekend, maybe NEAF brings some news...

Regarding eyepieces evaluation, i only care for comparative evaluations on the same scope, on the same minute, and swaping several times for confirmation. Everything else can be contaminated by so many factors that is not reliable. So when you say that you saw the Horsehead with the Pan 24, did you try there in that moment with another eyepiece of similar focal length to check the difference? And it is also important to always check that both eyepieces are absolutely clean.

Pedro

[John]

...The author of the report above is very credible..... 

Yes, Bill is a member here 

I agree with you about useful evaluation of eyepieces being in the same scope, same observer, same target and on the same occasion. I'm lucky to be loaned eyepieces of similar specifications to compare in this way but most folks don't have that luxury so have to relay on the reports of others.

TV coatings have improved over the years and the Panoptic is an older line. I've no doubt that the Delos would show higher transmission. When and if TV produce Delos type eyepieces to cover the 20mm - 40mm focal lengths I guess the Panoptics could be phased out, as the Radians have been, all but the 3mm.

What options are you considering as an alternative to the Panoptic 24's ?. The original poster might be interested in other possibilities.

[pbsastro]

Well, for this application (binoviewer) I would prefer Pan type (all lenses after focal plane) than Delos type (with lenses before focal plane) as Pan type is more compact, moreover when the large lenses required for the 24mm would not fit the 1.25" barrel and would have to be placed above the 1.25" barrel.

My alternatives would be:

ZAO-34 (the best, but impossible to get, moreover a pair)

Eudiascopic 35 or 30

Tak LE 30

Pan 24

ES-68  24

XW 20 (field stop only 24mm)

Currently I have a pair of Zeiss 25 aspheric, but I am looking to use the full 28mm of the bino, so I am split between a wider 24mm or a 30-35mm. I think I prefer a wider 24, and the XW 20 field stop is only 24mm, so to maximize the bino 28mm it would be either the Pan 24 or the ES 24. Tha Pan is sharper of-axis, the ES is brighter and less pin-cushion.

Another alternative would be to use a pair of Ethos (13 or 17) but that would be too heavy on the bino. I already have a pair of Ethos 17, I may try to screw it directly to the markV with the holders T-thread. The Ethos 17 has the same field stop as the Eudiascopic 35 (29mm), but the field stop is located 45mm above.

Pedro

[Naemeth]

I'm all for improvements to current eyepiece lines, and the invention of new ones. But, to suggest that the Panoptics should be disregarded due to a slightly lower level of transmission feels wrong to me. The 24mm Panoptic I have is a lovely eyepiece to use, and whilst I don't have any other 24mm widefields to compare it to I don't feel I need to. It gives me good deep sky performance, good edge performance and more importantly often stays in the focuser . No eyepiece design is perfect, it is always a compromise. Find what is important to you and look for the eyepiece that will best fill it.

Perhaps best to test the contenders yourself to see which one you prefer Pedro? It's no wonder that this is an expensive hobby...

Could two good quality orthos do well here?

[AlexB67]

Similar criticism have been made about the radian line low transmissions, some review show that it can be a difference on faint stuff I recall,, but there again, I got my Radian mainly for planets and brighter targets. That said, that is not to say I find it is poor by any means on fainter stuff.  The lovely dark sky the TV renders makes up a lot, and contrast is a major factor as well as transmission for detecting faint stuff against the background, and to that end I find the Radian I have does really well compared to my old cheapo SW 6mm that was similar in brightness, but no competition in terms of contrast and background darkness, though I have no doubt the Radian line would not be king in that department for the faintest of faintest compared to some others.

I never looked through a pan or owned one, but I am sort of thinking that pans, though entirely different line  but similar gen have some of that similarity in character that some like and some don't in the Radian line with that generation of coatings, a well as lower transmission the slightly non neutral tone as well that some seem to like and some don't.  Some even call it the TV coffee colour, but I like it anyway  .

Anyway, the only way I can tell the Radian is less neutral is by putting in my 5mm BGO in the scope straight after. in that case yes. If I used the radian all night I couldn't, I find it is actually quite subtle difference and only by knowing having made the comparison I am aware of it.  I can't state for certain since I do not have a 6mm BGO to compare, but even the 5mm BGO I have is actually a little brighter I think it seems on Jupiter compared to 6mm Radian, the moon also a tiny tad more contrasty.  So I can see some of that TV character that is often discussed in that gen of eyepieces which may also be in the pans to some degree I am guessing, though I only have one Radian to go on and perhaps a good imagination  .

[alan potts]

Everyone is entitled to their opinion but for me the 24mm Panoptic is a keeper unless something else better comes along. Without Panoptic's on the market where does a man like me look for a high quality wide field in a long scope. I can only think of 3, the 42mm Vixen, the Meade/ExSc 40mm SWA and the Panoptic 41mm. I guess the other answer is but another scope, done that.

I also owned the Meade 24mm at the same time as one of my 24mm Pans and I can't say I could see any transmission differences, however as said the Pan was sharper in general but not by a massive margin, I do have a very dark site BTW.

I am also of the opinion that Radians are a good deal better than many reviews state and must be one of the best S/H buys there is.

Alan.

[AlexB67]

I am also of the opinion that Radians are a good deal better than many reviews state and must be one of the best S/H buys there is.

Alan.

I am certainly glad I bought the 6mm and will not part with it, it is a jupiter killer  . I love the way it renders colour on the bands and red spot and the contrast it offers on said planet , seems to me it is almost as if it is made for it. That being said, still a great all rounder for other stuff too like globulars, PNs in my scope.

Glad you helped me be convinced to go try that route some time back when we discussed it and you partly to thank for that.    Not that I ever  looked through a 6mm Delos to compare  but given their prices, as you say a bargain these 2nd hand Radians I think. I find the 60 degrees plenty enough on planets in a Dob, even in a fast scope like mine, you can let it drift pretty much to the edge without seeing dropoff, impressive bit of kit indeed and very relaxing to look through.

Sorry for the OT.

[michael.h.f.wilkinson]

The Radians I had were great. The Pentax XF 8.5 just edged out the Radian 8mm, and the XW10 is a small improvement over the Radian 10mm in some matters, and noticeably in FOV. One of the clearest differences I spotted was a slightly warmer tone to the Radians compared to the XF, XW and Delos. Having said that, the effect could really only be seen in direct comparison, and went unnoticed through the years I used the Radian 8 and 10 as my stalwart planetary EPs. 

I have never looked through a Panoptic so cannot comment on their merits, but reading the report referred to above, I wondered about the impact of AFOV on the appearance of clusters. Given a 90% transmission of the Panoptic (let's be a pessimist) and 98% (optimistic) for the ZAO, the difference in limiting magnitude will be 0.092 magnitudes. This can influence the numbers of stars seen in a cluster, but by how much depends on a lot of factors. I wonder if the smaller AFOV, and hence a larger black area in view of the eye could lead to a slight perceived boost in sensitivity of the eye. This effect is similar to the disk of a planet appearing larger in a 10 mm Radian compared to a 10mm XW, in this case because we instinctively compare the size of the disk to the size of the FOV.

[pbsastro]

I have never looked through a Panoptic so cannot comment on their merits, but reading the report referred to above, I wondered about the impact of AFOV on the appearance of clusters. Given a 90% transmission of the Panoptic (let's be a pessimist) and 98% (optimistic) for the ZAO, the difference in limiting magnitude will be 0.092 magnitudes. This can influence the numbers of stars seen in a cluster, but by how much depends on a lot of factors. I wonder if the smaller AFOV, and hence a larger black area in view of the eye could lead to a slight perceived boost in sensitivity of the eye. This effect is similar to the disk of a planet appearing larger in a 10 mm Radian compared to a 10mm XW, in this case because we instinctively compare the size of the disk to the size of the FOV.

The AFOV can not be a factor as the Pan 24 is directly comapred to the ES-68 24:

"I particularly liked the precision of the star points in the TV Panoptic, yet often found myself reaching to the ES-68 as a preferred viewing choice because of the brighter image it provided, impression of a darker background, and the more engaging character it gave the target being viewed."

"The TV Panoptic gave the dimmest view of the Rank B through E eyepieces. In comparison to the ES-68, the brightest of the eyepieces in this group, the TV Panoptic’s view looked much dimmer overall with a greatly reduced dimensionality. To the TV Panoptic’s credit though was the precision at which it rendered star points, seeming just a little more refined and tighter in the TV Panoptic compared to any other eyepieces in the middle of the pack."

Also as we all seem to agree, a 5% diffference is too small to be signifcant, and as the ES should not exceed 94%, I am inclined to assume the tested Pan has 85%.maximum, but that is my speculation. And as said before, it may be an old Pan.

[michael.h.f.wilkinson]

The AFOV can not be a factor as the Pan 24 is directly comapred to the ES-68 24:

"I particularly liked the precision of the star points in the TV Panoptic, yet often found myself reaching to the ES-68 as a preferred viewing choice because of the brighter image it provided, impression of a darker background, and the more engaging character it gave the target being viewed."

"The TV Panoptic gave the dimmest view of the Rank B through E eyepieces. In comparison to the ES-68, the brightest of the eyepieces in this group, the TV Panoptic’s view looked much dimmer overall with a greatly reduced dimensionality. To the TV Panoptic’s credit though was the precision at which it rendered star points, seeming just a little more refined and tighter in the TV Panoptic compared to any other eyepieces in the middle of the pack."

Also as we all seem to agree, a 5% diffference is too small to be signifcant, and as the ES should not exceed 94%, I am inclined to assume the tested Pan has 85%.maximum, but that is my speculation. And as said before, it may be an old Pan.

Fair enough, but the ES ranks lower than the ZAO as I understand in the DSO test, and that may be in part due to AFOV issues.  I myself would not say 5% difference is undetectable. 5% equates to roughly 0.05 magnitudes. This seems insignificant but could make quite a difference if there are many stars at or near the limit of visual detection.

[Phil Creed]

Televue still makes the 19mm and 24mm Panoptics for the binoviewer crowd, where their relatively Lilliputian physical presence is very much appreciated.  But you're right, a 19-/20-mm has been a dead zone for FAR too long if you're looking for a well-corrected, long-eye relief widefield eyepiece.  Most eyepiece wearers with available funds gravitate towards either a 17T4 or 22T4 if looking for ultrawides, or a 17LVW / 22LVW if looking for superwides.  The Pentax 20mm XW is a viable option if--IF--you've got a Paracorr, as the field curvature is an issue w/o a coma corrector to flatten the field.

If a 2"-, 20mm-ish Delos comes out, I'm SOOOOO getting one.

Clear Skies,
Phil

[Phil Creed]

My bad.  The above (Post #43) was a response to Naemeth's post from 30 Jan 2014; I should have noted that it was page 1 of 3 at that point.

How do you edit posts in SGL?

Clear Skies,

Phil

[Joves]

My bad.  The above (Post #43) was a response to Naemeth's post from 30 Jan 2014; I should have noted that it was page 1 of 3 at that point.

How do you edit posts in SGL?

Clear Skies,

Phil

Hi Phil,

Unfortunately, you need a minimum number of posts before you can edit. I believe it is 250... May be 500 though... Definitely one of those. Either way, yours is fine where it is and still makes sense in this thread.

Cheers,

Aaron

[michael.h.f.wilkinson]

My bad.  The above (Post #43) was a response to Naemeth's post from 30 Jan 2014; I should have noted that it was page 1 of 3 at that point.

How do you edit posts in SGL?

Clear Skies,

Phil

After 250 posts you will be allowed to edit posts. We had several cases of people spouting abuse and then removing it before us mods could respond to complaint. Sad but true.  After 250 posts there is a time limit (30 minutes I believe) within which you can edit your post. In the mean time, proof reading helps. If you accidentally post something really embarrassing you can always report the post and ask us to edit it.