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ES 82* 18 or Meade 5K 20?

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#1 mitaccio

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Posted 11 February 2013 - 06:43 AM

I am looking for an eyepiece 20-18mm to fill the gap I have. Currently have a 24mm Meade 5K and a ES 82* 14mm & 8.8mm Both the ES 82* 18mm and the Meade 5K 20mm are $149, waterproof, and would match my existing eyepieces. Here's the numbers for my scope:

Meade 5K 20mm: 101X, 2.0 Exit Pupil at 17mm eye relief
ES 82* 18: 113X, 1.8 Exit Pupil at 13mm eye relief

Both eyepieces are very close in design from my understanding. But which one is the better performer? I am leaning towards the Meade, even though it is heavier as it offers a slightly bigger exit pupil.

#2 csrlice12

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Posted 11 February 2013 - 08:34 AM

To be truthful, I usually jump from the 24mm down to the 11mm, but will admit, that ES82* 18mm, while a little short on eye relief (not bad, but if you wear glasses it can get a little touchy), it throws out some fantastic views. Great on the moon and DSOs.

#3 Astrojensen

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Posted 11 February 2013 - 10:22 AM

My ES82° 18mm is one of the sharpest eyepieces I've ever seen. It is as sharp, if not sharper than my 18mm UO ortho. It seems to snap into focus better than the 18mm UO.

On my 12" f/5, I don't use it as much as I thought I would, jumping directly to the ES 11mm from the ES 30, but it's a smash hit on my long-focus refractors.


Clear skies!
Thomas, Denmark

#4 hottr6

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Posted 11 February 2013 - 01:05 PM

Meade 5K 20mm: 101X, 2.0 Exit Pupil at 17mm eye relief
ES 82* 18: 113X, 1.8 Exit Pupil at 13mm eye relief

Both eyepieces are very close in design from my understanding. But which one is the better performer? I am leaning towards the Meade, even though it is heavier as it offers a slightly bigger exit pupil.

I thought the Meade S5K 20mm is a SWA (72-degree) design, and the ES a UWA. How could they be "close in design"? :question:

If you remove the shroud from the Meade, the 20mm is quite a petite eyepiece.

#5 csrlice12

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Posted 11 February 2013 - 01:29 PM

All I can say is between the two--go with the ES 82* 18mm and don't look back.....

#6 SteveG

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Posted 11 February 2013 - 01:37 PM

The Meade 5K SWA has a 68* afov. It has excellent optics and very comfortable eye relief.

#7 stevew

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Posted 11 February 2013 - 03:31 PM

I'll second the ES 18mm.
I have one and love it.
It;s a very sharp eyepiece


Steve

#8 Scanning4Comets

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Posted 11 February 2013 - 04:05 PM

I have owned BOTH eyepieces.

Well, I *did* own the 18mm Meade series 5000 18mm UWA and there was quite a bit of field curvature in my scope that I tried to ignore after a while of using it. At first I just wrote it off as nothing, but over time it bugged me.

Bill P will probably say the same, as he *did* warn me about the field curvature on the 18mm UWA, but I went ahead and tried it anyways. If you have a Paracorr, it might clean the edges up.....IMO, however, the 18mm series 5000 was cozy to use, minus the FC.

I then picked up a 20mm Meade 5000 68 degree SWA and I also tried the 20mm 68 degree ES. The 20mm ES 68 and the Meade 5000 68 performed pretty much the same in my scope. In the end, I ended up getting a 22mm Vixen LVW which smoked them all.

I still have the 22mm Vixen LVW, which says a lot for me because I flip eyepieces like people flip coins, LOL.

Cheers,

#9 Astrojensen

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Posted 11 February 2013 - 04:25 PM

The ES 82° 18mm has essentially zero field curvature. The edges may still be unsharp, though, depending on the scope. In my 6" f/8 refractor, it is nearly perfectly sharp to the edge, in my 12" f/5 dob, it shows coma, as you would expect. The coma is much smaller and well-focused than in my 70° 20mm GSO Superview, which was also nearly sharp to the edge in my 6" f/8 refractor.


Clear skies!
Thomas, Denmark

#10 aa5te

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Posted 11 February 2013 - 06:24 PM

No, there actually is a Meade 5K 20mm UWA (not SWA) out now:
Meade 5000 Series 20mm UWA

#11 Scanning4Comets

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Posted 11 February 2013 - 06:25 PM

Field curvature *did* show in the 18mm UWA in my 10" f/4.7 and it also did in Bill P's scope as well. These are pretty much the same eyepieces in different housings, unless I am mistaken and the ES 18mm UWA is different than the Meade Series 5000 18mm UWA?

Field curvature is when you can refocus the edges sharp like the center, but when the edge is sharp the center is blurry, and vice versa. Coma cannot be "re-focused" like FC can.

Cheers,

#12 aa5te

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Posted 11 February 2013 - 06:44 PM

The ES 18 and the Meade 20 are both 2", whereas the Meade 18mm is 1.25". Not sure if that'll make a difference to you.

#13 mitaccio

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Posted 11 February 2013 - 06:48 PM

Sorry, didn't know there was a 20mm SWA. I am looking at the UWA, 82* Meade. Already hearing some great things about the ES 18. Thinking of searching one out.

#14 Lentini

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Posted 11 February 2013 - 11:54 PM

20mm ES 100 degree is a rocking eyepiece.

#15 Scanning4Comets

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Posted 11 February 2013 - 11:58 PM

YES TO THE ABOVE !!!! :waytogo: :ubetcha:

Cheers,

#16 Astrojensen

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Posted 12 February 2013 - 03:46 AM

Field curvature is when you can refocus the edges sharp like the center, but when the edge is sharp the center is blurry, and vice versa. Coma cannot be "re-focused" like FC can.


I know. What I wanted to say was that the ES82 18mm is a flat field eyepiece. In my coma-free long focal length refractors (1200mm and 1600mm focal length), the eyepiece is sharp to the very edge. There should be a tiny amount of field curvature near the edge in the 1200mm focal length 6", but I am not seeing it, likely because it is so little, that my eyes refocus without effort.

The 12" f/5 has an even flatter field than the refractors, but it has coma. The coma is sharply focused, but because of it, stars aren't sharp near the edge. This has nothing to do with field curvature in either scope or eyepiece.

In my 72mm f/6 refractor, there is clearly visible field curvature, mostly in the 30mm, but also to a milder degree in the 18mm. The 11mm is nearly perfect.

There has been no visible astigmatism near the edge in any of my telescopes.

The ES 18mm has an essentially perfectly flat field. In a flat-field coma-free telescope, it will deliver pinpoint images to the very edge.


Clear skies!
Thomas, Denmark

#17 rflinn68

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Posted 12 February 2013 - 12:13 PM

Love all my ES eyepieces and I suspect the ES82 18mm is every bit as good, maybe even better from what I have heard but I havent looked through one yet. I already own a few ES 82's so I'd get the ES 18 because I want the whole set.

#18 stevew

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Posted 13 February 2013 - 10:57 PM

The ES 82° 18mm has essentially zero field curvature.
Clear skies!
Thomas, Denmark

I have not noticed any field curvature in the ES 18mm in either my 130mm F-7 or my 105 F-6.
The stars are essentially sharp to the edge of the field.

Steve

#19 RogueGazer

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Posted 14 February 2013 - 01:54 AM

I purchased the ES 82* 18mm and I do enjoy using it on lower light targets but the first time I pointed it at the moon I was majorly disappointed. The moon was surrounded by a bright orange ring that completely ruined the view. This was using my Z8 Dob. I was concerned I got a lemon so I emailed ES via their website and they promptly replied...

"I have spoken with with our field specialist and our owner about this before and this occurs with these types of eye pieces when viewing bright objects.  It is not a defect in the eyepieces it is an aberation that occurs in combination with how the light goes through the eyepiece and how your eye receives the light. It is my understanding that it lessens when viewed from and certain distance away from the eyepiece or when viewed at an a light angle."

So while I do enjoy viewing many dim object the moon can only be enjoyed when it is just a small crescent. Anything more with that EP is too much.

#20 Scanning4Comets

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Posted 14 February 2013 - 02:29 AM

I have not noticed any field curvature in the ES 18mm in either my 130mm F-7 or my 105 F-6.
The stars are essentially sharp to the edge of the field.

Steve


Field Curvature all depends on how long / short your focal length is. You can see a lot more of it in short focal length scopes!

Cheers,

"I have spoken with with our field specialist and our owner about this before and this occurs with these types of eye pieces when viewing bright objects. It is not a defect in the eyepieces it is an aberration that occurs in combination with how the light goes through the eyepiece and how your eye receives the light. It is my understanding that it lessens when viewed from and certain distance away from the eyepiece or when viewed at a light angle."


What a crock of doo-doo that quote is! :lol:

Cheers,

#21 Astrojensen

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Posted 14 February 2013 - 02:44 AM

Field Curvature all depends on how long / short your focal length is.



Both telescopes AND eyepieces can have field curvature. Or they can have flat fields. It depends on the design. It is therefore wrong to say that field curvature all depends on the focal length [of the telescope].

What a crock of doo-doo that quote is!


It was actually quite correct.


Clear skies!
Thomas, Denmark

#22 RogueGazer

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Posted 14 February 2013 - 05:22 AM

[quote name="Scanning4Comets"]"I have spoken with with our field specialist and our owner about this before and this occurs with these types of eye pieces when viewing bright objects. It is not a defect in the eyepieces it is an aberration that occurs in combination with how the light goes through the eyepiece and how your eye receives the light. It is my understanding that it lessens when viewed from and certain distance away from the eyepiece or when viewed at a light angle."[/quote]

What a crock of doo-doo that quote is! :lol:

Cheers, [/quote]

If I have to pull my eye back further to correct the problem there goes my 82* AFOV. I might as well use a plossl not that what he said matters beause nothing I have tried fixes the problem unless I get so far back from the EP I see nothing at all. I have read a lot of great reviews on this eyepiece and how great the moon looks. Even my 11 year old son thought it looked like trash. I suspect I may have gotten a bit of a dud but fighting it is probably a losing battle. I just wont use it for lunar observations. It still is a great lower light EP.

#23 Scanning4Comets

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Posted 14 February 2013 - 05:40 AM

Both telescopes AND eyepieces can have field curvature. Or they can have flat fields. It depends on the design. It is therefore wrong to say that field curvature all depends on the focal length [of the telescope].


Yes, however, You can take a 14mm Pentax XW, put it in my 10" F/4.7 and the field curvature is very strong. Now, take the same eyepiece and put it in an F/10 CAT telescope and the field curvature is no longer there.

Did this many times with many different eyepieces!

Cheers,

#24 Scanning4Comets

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Posted 14 February 2013 - 05:42 AM

If I have to pull my eye back further to correct the problem there goes my 82* AFOV. I might as well use a plossl not that what he said matters beause nothing I have tried fixes the problem unless I get so far back from the EP I see nothing at all. I have read a lot of great reviews on this eyepiece and how great the moon looks. Even my 11 year old son thought it looked like trash. I suspect I may have gotten a bit of a dud but fighting it is probably a losing battle. I just wont use it for lunar observations. It still is a great lower light EP.


The ES 82's and some of the Meade Series 5000 UWA eyepieces have poor baffling and a poor design on the bottom of the eyepiece. There is a thread here somewhere showing a felt ring added to the bottom of the eyepiece to correct bad flaring and internal reflections. Bright targets like Jupiter and the moon show really bad internal reflections, so the quote from this "certain person" from ES is handing you, or someone else a big load of BULL to try and save face.

Cheers,

#25 RogueGazer

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Posted 14 February 2013 - 06:26 AM

The ES 82's and some of the Meade Series 5000 UWA eyepieces have poor baffling and a poor design on the bottom of the eyepiece. There is a thread here somewhere showing a felt ring added to the bottom of the eyepiece to correct bad flaring and internal reflections. Bright targets like Jupiter and the moon show really bad internal reflections, so the quote from this "certain person" from ES is handing you, or someone else a big load of BULL to try and save face.

Cheers,


I read about that as well.I will rig something up similar to their rig job and see how it works. I have low expectations so I wont get too disappointed when it fails. Always borrow money from a pessimist. He won't expect it back :lol:






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