43 replies to this topic

[Echolight]

Ok echolight , so maybe this 20mm should compliment my q70 38mm better than a 24mm 82’ afov
Thank for your advice !

I don’t think either way is wrong. 
 

If I had an ES82 24mm I doubt I’d be running out to replace it.

 

But myself, just starting out, I chose the APM 20-100 because it was cheaper. And covered a little more ground in my eyepiece lineup. So I could get by with a bigger jump and need one less eyepiece in the end. I easily could have gone with a 38-70, 24-82, 17.5-76, and then whatever below that.

 

Some people have a full set of Panoptics, Naglers, AND Ethos.

 

For me, five semi-premium eyepieces seems like excess. Or right now, three would be a luxury.

Edited by Echolight, 04 October 2020 - 09:01 AM.

[mich_al]

I started with a couple of Pentax XW's with my C9.25", later have the whole set.  The lower mm's get sparse use in the C9.25 but are very handy with my refractors.

[Firewalker]

My two cents

 

There is no one best eyepiece line.  It's a question of priorities .

 

I had both the 14 mm and 20 mm ES 100s . I found them less sharp at the edge in my F/5 scopes than my Naglers , the field was not visible in a single glance, I had to peek to see edge.  As a result I kept 12 mm , 16 mm and 20 mm Naglers,  it was a toss up,  the wider field versus the better field. 

 

Through good fortune I was able to purchase the 21 mm,  13 mm and 8 mm Ethos's.  They were sharp-sharp across the field and I could take in the entire view.  For me,  while subtle , those were important differences and the two Ethos's replaced the other 5.

 

Priorities:

 

I value edge correction , I use a Paracorr at F/5.5, my primary refractor is the NP-101, no field curvature.  I have owned my 12.5 inch F/4.06 for nearly 20 years..  Those two scopes are demanding of eyepieces.  My eyes have no astigmatism , no distance correction. 

 

If I had slower scopes , if I wasn't using coma correctors on my fast scopes, if I had different eyes,  I might have different priorities.  If I weren't a 100% star Hopper spending over 100 nights a year under dark skies with some pretty big scopes,  I might have different priorities. 

 

Jon

Hi thank you for sharing, mine is a 9.25 with F10, so i guess having a wider field make less of a difference than In your F5.5 am i mistaking ?

 

I have my scope since about 3 weeks and i already spent 10 nights outside .. i wish i’d live in a darker place but still alot of fun, can’t wait to take it outside.

 

Regards

 

I started with a couple of Pentax XW's with my C9.25", later have the whole set.  The lower mm's get sparse use in the C9.25 but are very handy with my refractors.

Hi,

 

I might give a look to pentax too but the truth is that the seller near me sell them the same price than Nagler or Delos so i am not sure.

 

Thank you for sharing 

[Starman1]

Hi thank you for sharing, mine is a 9.25 with F10, so i guess having a wider field make less of a difference than In your F5.5 am i mistaking ?

 

I have my scope since about 3 weeks and i already spent 10 nights outside .. i wish i’d live in a darker place but still alot of fun, can’t wait to take it outside.

 

Regards

 

Hi,

 

 

You mean "having a narrower field".

An f/10 scope has a narrower field than an f/5 scope of the same size.

 

But you are not wrong--having a longer f/ratio is easier on eyepieces, so the edges of the field are typically better at f/10.

That assumes the eyepieces have no inherent astigmatism (and many do), and that you have a flattened field, no coma, version of the SCT, like an Edge.

If you have a normal SCT, the field is a bit curved and there is also residual coma in the scope (not much--about the same as an f/6 newtonian).

It's still fairly easy on eyepieces, but not quite like an f/8 newtonian.

Edited by Starman1, 04 October 2020 - 02:36 PM.

[Firewalker]

You mean "having a narrower field".

An f/10 scope has a narrower field than an f/5 scope of the same size.

 

But you are not wrong--having a longer f/ratio is easier on eyepieces, so the edges of the field are typically better at f/10.

That assumes the eyepieces have no inherent astigmatism (and many do), and that you have a flattened field, no coma, version of the SCT, like an Edge.

If you have a normal SCT, the field is a bit curved and there is also residual coma in the scope (not much--about the same as an f/6 newtonian).

It's still fairly easy on eyepieces, but not quite like an f/8 newtonian.

Hi Starman,

 

thank you for those informations, i always like to learn more, so does it meants that i won’t see much difference with a narrower Field of view ?

 

Infact i wonder because Ethos are litterally twice the price of Nagler and/or Delos.

 

do you think that i will have regrets choosing Delos over Nagler, which series would you choose, will i miss that 10 degrees 72 instead of 82, and why are they the same prices , are Delos optics superior to Nagler ?

 

Let me know what you think

 

thank you again your time is much appreciated

[Starman1]

Hi Starman,

 

1.thank you for those informations, i always like to learn more, so does it meants that i won’t see much difference with a narrower Field of view ?

 

Infact i wonder because Ethos are litterally twice the price of Nagler and/or Delos.

 

2.do you think that i will have regrets choosing Delos over Nagler, which series would you choose, 3. will i miss that 10 degrees 72 instead of 82, 4. and why are they the same prices ,5. are Delos optics superior to Nagler ?

 

Let me know what you think

 

thank you again your time is much appreciated

I've numbered your questions:

1) the narrower the field of view, assuming equal eyepiece quality, the less in the way of aberrations at the edge in general.

In a specific case, the eyepiece could see more of less astigmatism depending on the eyepiece design.

Some narrow field eyepieces have poorly-corrected outer fields.  Some widefield eyepieces have excellent correction.

So it depends more on the eyepiece than the apparent field.

2) The Delos are truly superb eyepieces, and they are usable by glasses wearers, which Naglers are not (except the 2 longest focal lengths).  You won't have any regrets.

3) Probably not.  72° is still pretty wide.  But only you can answer this question by comparing them yourself.

4).The comparable focal lengths of Naglers are smaller and lighter and use less glass than the Delos.  Also, some of them (13mm -) are made in Japan, which has higher labor costs than Taiwan.

5) No, just different.  Lab tests show both series have excellent optics.

[MessyA]

I agree that the 2" diagonal purchase is important- get a good one. I love the Baader clicklock because it's not just an excellent optical piece, but the clicklock, if you are getting into the heavy EP's like Panoptics, is really secure and easy to use.  You asked why a 35 Pan instead of a 41 Pan. I have never owned the 41 but from all I've read, there is very little advantage to the 41 as far as FOV, in an SCT so why pay even more? The 35 Pan in my 8" SCT, gives spectacular widefield low power views. It is a pretty heavy EP. I have my optical tube moved far forward on the dove tail to compensate. 

Edited by MessyA, 04 October 2020 - 06:17 PM.

[Firewalker]

I've numbered your questions:

1) the narrower the field of view, assuming equal eyepiece quality, the less in the way of aberrations at the edge in general.

In a specific case, the eyepiece could see more of less astigmatism depending on the eyepiece design.

Some narrow field eyepieces have poorly-corrected outer fields.  Some widefield eyepieces have excellent correction.

So it depends more on the eyepiece than the apparent field.

2) The Delos are truly superb eyepieces, and they are usable by glasses wearers, which Naglers are not (except the 2 longest focal lengths).  You won't have any regrets.

3) Probably not.  72° is still pretty wide.  But only you can answer this question by comparing them yourself.

4).The comparable focal lengths of Naglers are smaller and lighter and use less glass than the Delos.  Also, some of them (13mm -) are made in Japan, which has higher labor costs than Taiwan.

5) No, just different.  Lab tests show both series have excellent optics.

Hello Again, thanks for all those great informations, it helps me alot.

 

Since me and my girlfriend mostly do planetary observations, we plan on trying to look at Mars, Jupiter and Saturn, we might pull the trigger on the Delos 8mm and the 10mm tomorrow

 

We want to try to see Mars at opposition tomorrow and before the 13th of october.

 

I guess that since i mostly want to do planetary observation and those planets are smalls i don’t see why i would need a larger FOV than 72.

Maybe a larger FOV would be more useful on the 13 / 14 mm eyepiece and the 20 so see DSO and other things than planets.

 

So even if i don’t have eyeglasses i tend to favor the delos for observing planets, unless i’m missing something a larger FOV would not help me see them and Delos much cheaper than ethos i wonder why someone would want a 100mm FOV on a 8mm or 10m but i understand i’m probably missing something in the equation.

 

 

 

I agree that the 2" diagonal purchase is important- get a good one. I love the Baader clicklock because it's not just an excellent optical piece, but the clicklock, if you are getting into the heavy EP's like Panoptics, is really secure and easy to use.  You asked why a 35 Pan instead of a 41 Pan. I have never owned the 41 but from all I've read, there is very little advantage to the 41 as far as FOV, in an SCT so why pay even more? The 35 Pan in my 8" SCT, gives spectacular widefield low power views. It is a pretty heavy EP. I have my optical tube moved far forward on the dove tail to compensate. 

Thanks for the tip, i will definately look into that click lock baader diagonal, i have read about it on many websites..

 

Good call on the 35 vs 41, definately will add more information on my inquest

 

Thank you

Edited by Firewalker, 05 October 2020 - 06:33 AM.

[Boeglewatcher]

Hello Again, thanks for all those great informations, it helps me alot.

 

Since me and my girlfriend mostly do planetary observations, we plan on trying to look at Mars, Jupiter and Saturn, we might pull the trigger on the Delos 8mm and the 10mm tomorrow

 

We want to try to see Mars at opposition tomorrow and before the 13th of october.

 

I guess that since i mostly want to do planetary observation and those planets are smalls i don’t see why i would need a larger FOV than 72.

Maybe a larger FOV would be more useful on the 13 / 14 mm eyepiece and the 20 so see DSO and other things than planets.

 

So even if i don’t have eyeglasses i tend to favor the delos for observing planets, unless i’m missing something a larger FOV would not help me see them and i think the delos gives you a better image, i wonder why someone would want a 100mm FOV on a 8mm or 10m but i understand i’m probably missing something in the equation.

 

 

 

Thanks for the tip, i will definately look into that click lock baader diagonal, i have read about it on many websites..

 

Good call on the 35 vs 41, definately will add more information on my inquest

 

Thank you

actually, if you are into planets only, a classic ortho type eyepiece will suit you best, like a Baader 6mm, 10mm or 18mm. (there are many other companies offering these razor sharp eyepieces w FOV around 50deg). the wider FOV (like above 80deg or even 100deg) is mostly used for star clusters, nebular, galaxies.  

[Voyager 3]

Hello Again, thanks for all those great informations, it helps me alot.

Since me and my girlfriend mostly do planetary observations, we plan on trying to look at Mars, Jupiter and Saturn, we might pull the trigger on the Delos 8mm and the 10mm tomorrow

We want to try to see Mars at opposition tomorrow and before the 13th of october.

I guess that since i mostly want to do planetary observation and those planets are smalls i don’t see why i would need a larger FOV than 72.
Maybe a larger FOV would be more useful on the 13 / 14 mm eyepiece and the 20 so see DSO and other things than planets.

So even if i don’t have eyeglasses i tend to favor the delos for observing planets, unless i’m missing something a larger FOV would not help me see them and Delos much cheaper than ethos i wonder why someone would want a 100mm FOV on a 8mm or 10m but i understand i’m probably missing something in the equation.



Thanks for the tip, i will definately look into that click lock baader diagonal, i have read about it on many websites..

Good call on the 35 vs 41, definately will add more information on my inquest

Thank you

It depends upon your F/ratio. Some scopes have fast optics like F/4 and F/5 where the 8E and 10E gives THE 2mm exit pupil , which many prefer as it gives the highest visual acuity . As this will be the most used EP , they prefer it to have large AFOV . The reason that 3.7E , 4.7 E , 6E are famous (well not that much comparing to longer FLs) is that when shorter FLs are used , you will have smaller TFOVs . Also it's a daunting task for dob/untracked scope owners to track objects at these high mags . Without large AFOVs the objects would zip across the field . Many dob owners prefer the ethos against Delos at shorter Focal lengths as the difference is subtle at best at good conditions which is rare .
Also some enthusiasts prefer to frame the moon at 180-200× .

Edited by Voyager 3, 05 October 2020 - 07:48 AM.

[Starman1]

Hello Again, thanks for all those great informations, it helps me alot.

 

Since me and my girlfriend mostly do planetary observations, we plan on trying to look at Mars, Jupiter and Saturn, we might pull the trigger on the Delos 8mm and the 10mm tomorrow

 

We want to try to see Mars at opposition tomorrow and before the 13th of october.

 

I guess that since i mostly want to do planetary observation and those planets are smalls i don’t see why i would need a larger FOV than 72.

Maybe a larger FOV would be more useful on the 13 / 14 mm eyepiece and the 20 so see DSO and other things than planets.

 

So even if i don’t have eyeglasses i tend to favor the delos for observing planets, unless i’m missing something a larger FOV would not help me see them and Delos much cheaper than ethos i wonder why someone would want a 100mm FOV on a 8mm or 10m but i understand i’m probably missing something in the equation.

 

 

 

Thanks for the tip, i will definately look into that click lock baader diagonal, i have read about it on many websites..

 

Good call on the 35 vs 41, definately will add more information on my inquest

 

Thank you

1) Mars is still large until Mid November and details can be see at high powers even longer.  You don't just have 1 shot to see it.  It was largest on October 6th, even though opposition is October 12.

2) You don't need wide fields for planet-only viewing.  And I'd recommend the Delites over the Delos for that type of viewing.  if you ever want to view something other than planets, though, a wider field would be preferable.

I never understood planet-only viewing because thousands of other objects are visible in your scope, so why confine yourself to only 5 or 6?  Plus, there are better planet-specific scopes than a 9.25" SCT. with its large secondary mirror.

I think you should try looking at star clusters on the side.  You just might discover there is more to look at than just planets.

3) Wider fields are less bounded and show more sky.  This can be engaging to observe, and often multiple objects can be seen in one field.  The 9.25" has a long focal length and narrow field of view inherently.  Many of today's scopes have much shorter focal lengths and yield much larger true fields.  That's not important for planets, but is very useful for deep sky.  So widefield eyepieces are important for deep sky observing in the SCT.

4) The 41mm will yield a larger true field than the 35mm, and a larger exit pupil (brighter image), but would be contraindicated in a bright urban sky.  The extra field brightness would just produce less contrast, a brighter sky background, and a less desirable image.  In a dark sky, the 41 would be superb.  In a city, though, a 30-31mm might be a better choice for low power because the image would be better, with a darker sky background.

[gnowellsct]

Hello,

 

thank you for sharing, alot of nice eyepieces you have there my friend.

 

So the widest view you have is the nagler 31 mm, do you think the FOV is usable in an SCT since it’s 82 degrees ?

 

What do you mean by the eye relief was too long with the panoptic 41mm.

 

Thank you for your post !

It's usable.  You will, however, get a wider field of view with a Televue Pan Optic 41mm or the Pentax XW40.

 

You should learn to calculate exit pupil.  On an f/10 telescope the exit pupil is 1mm if you are using a 10mm ocular.  10mm ocular/10 focal ratio = 1mm exit pupil.   

 

Your target maximum magnification should as a practical matter be 0.5 mm exit pupil which is a 5 mm eyepiece.   In practice seeing will cap you at around 7 or 8 mm.  An exit pupil of 0.5 mm is the "customarily followed" cap on magnification.  In practice, as with driving speed limits, we all violate it from time to time.  But there's seldom any real need to.

 

Greg N

 

p.s. I would have Delos if I had to buy Televue.  But fortunately I have Pentax XWs.

[JohnnyLingo]

Since apparently nobody has suggested it yet, I would also suggest the ES 68-deg 40mm eyepiece for obtaining the largest true FOV with the C9.25. I use it in my C9.25 and it works perfectly. It is significantly cheaper than the 41mm Pan, but will give virtually the same image quality at f/10. Plus it's Argon-purged waterproof.

[whizbang]

+1 what JohnnyLingo said.

 

I have both the EVO925 and EVO8.  I recently pared down my eyepiece collection to three 2 inch eyepieces:

 

ES 40mm 68 degree

ES 24mm 82 degree

Nagler 17mm 82 degree

 

I have a ES 9mm 62 degree eyepiece for planetary or double star observing.  However, I usually grab a Mak for that.  So, the 9.25 just uses the wide angle lenses that are listed.

[adamckiewicz]

+1 what JohnnyLingo said.

I have both the EVO925 and EVO8. I recently pared down my eyepiece collection to three 2 inch eyepieces:

ES 40mm 68 degree
ES 24mm 82 degree
Nagler 17mm 82 degree

I have a ES 9mm 62 degree eyepiece for planetary or double star observing. However, I usu
ally grab a Mak for that. So, the 9.25 just uses the wide angle lenses that are listed.

Great!
I just bought a 40mm pentax xw. I’m looking for ES 24mm 82’ ( to replace my 25mm stock plossl) and morpheus 9mm. I have a 12mm artesky Ed wich I further will change for something else (lack of transparency) and a 9mm morpheus that i love! I also have a artesky Ed 5mm for collilation and that I use sometime for the moon or when a planet is high and the seeing good....
I think I might be happy with these eyepieces that can also work on faster apos or dobsons

Edited by adamckiewicz, 07 October 2020 - 10:16 AM.

[mr_snout]

If spending a lot of $$$ to get a guaranteed very high value without thinking, then go for the TV Delos EPs and 1-2 long-FL Panoptics, you cannot make a wrong decision by investing into them. They are like the Ferrari of EPs.

 

If you prefer to optimise price for value, then there are several better options than TV. With a marginal or even undetectable compromise of performance, you can cut the price by 50-60%. The APM UFF, the ES 68 and 82, and the Baader Morpheus series are worth considering, just to name a few. These could be considered the BMW, Mercedes-Benz, and Lexus of EPs (vs the Ferrari analog).

 

The UWA eyepieces, where you don't see the edge of the FOV (for $$$), are strongly preferred by some, and considered as a waste of light and money by others. The latter is because the human eye's FOV (i.e., peripheral vision) is about 70 degrees or less. If you have a classical SCT (i.e., no ACF or EdgeHD), then you might see no benefit of expanding the FOV to the outer field of your scope where coma error starts to be bothersome and might prefer maximizing your AFOV at ~70 degrees, at least at longer FLs.

 

I think you have to have a very trained eye to distinguish between a lot of these eyepieces. I have low/midrange high end EPs- Panoptics, a TV Plossl, Baader Morpheus, ES 82 etc. I honestly think I went overboard on my set. There is no regret in that I got them on sale and mostly with CC points. Won’t ever need anymore, I don’t think. But I think u are spot on with the Ferrari comment.

[Starman1]

The UWA eyepieces, where you don't see the edge of the FOV (for $$$), are strongly preferred by some, and considered as a waste of light and money by others. The latter is because the human eye's FOV (i.e., peripheral vision) is about 70 degrees or less. If you have a classical SCT (i.e., no ACF or EdgeHD), then you might see no benefit of expanding the FOV to the outer field of your scope where coma error starts to be bothersome and might prefer maximizing your AFOV at ~70 degrees, at least at longer FLs.

Just a slight segue from your post:

 

Human vision has 3 fields: peripheral vision, which extends to 145°-180° laterally and ~125° vertically.  That is the stage.

So far, no eyepiece has been made exceeding that.

It also has a "field of concentration" of approximately 30°.  it is what you swing your eye around to see other portions of the field.  This is the floodlight.

And it has a "field of maximum acuity and attention" that is about 5° wide.  When you look for details in a deep sky object, this is the approximate field width of examination.  This is the spotlight.

 

In eyepieces, up to about 70° can be used without really rolling the head over to look through the eyepiece at an angle.  If, however, you prefer to use that center 5° to closely examine the edge, you will have to roll your head over and look through the eyepiece at an angle to do so.  Whether you do so or not, I think, determines whether you prefer eyepieces narrower than this.

But certainly, for 80° and wider, rolling your head over and looking through the eyepiece at an angle is a standard way of using the eyepiece.  People who simply cannot do so, or do not want to do so, will not like these eyepieces.

I think it is an acquired skill which, once acquired, makes these eyepieces as simple to use as any others.

 

You are absolutely correct about outer field aberrations.  It probably doesn't pay to purposely acquire eyepieces with wide fields if those wide fields have heavily aberrated images in the outer fields--especially if they cost more.

[Firewalker]

Hello everyone,

 

Update :

 

The only astronomy shop in quebec city where i live did not have any televue in stock and did not plan to order anymore.

 

But they had nice discounts on ES eyepieces mostly on the 82 degrees series.
 

I got what they had left to start my collection :

 

ES 11mm 82 degrees paid 199 $ instead of 280 $

ES 14mm 82 degrees Paid 199 $ instead of 280 $

ES 24mm 82 degrees paid 270 instead of 470 cad everywhere else online in canada

 

they only had the 62 degrees they did not have the 68... so i pulled the trigger on the 62 hope it won’t be too bad to lose that 6 degree.

 

ES 40mm 62 degrees paid 209 instead of 290 CAD.

 

I really wanted to get televue since everyone love them so much but ... i couldn’t pass on that deal because even on amazon or anywhere else in canada, i could not have that price and everywhere had the listed regular prices i mentionned earlier.

 

All of your informations were totally great.

 

I wonder if i should complete the 82 degrees collection when they will receive some more at a discount.

 

The ones that i don’t have yet, 4.7mm , 6.7mm , 8.8mm , 18mm and 30mm.

Hesitating on the 4.7 because i understand it’s almost impossible to have a 500x magnification, but if me and my girlfriend could use it only once or twice a year and see the planets much closer we would be so happy.

 

6.7 = 350X is also making me hesitating.

 

Anyway it’s not for now but still interesting to discuss about it, we want to watch everything but we love planets and they seem so distant right now, at least in the 11mm.

 

Thank you all

[Boeglewatcher]

If you like to view through the 82degrees, no reason not to continue. You don’t need the large fov with a 5,6 or 8mm eyepiece for planets but might come handy if you decide to look at galaxies or star clusters. Most important is that you feel comfortable with the eyepiece. Planets can be great at higher mag when there is a little moisture in the sir which smoothens the seeing. You can get a 9mm and then add a good Barlow for the perfect nights