Jump to content

  •  

CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.

Photo

Meade 26mm 100AFOV

  • Please log in to reply
87 replies to this topic

#26 junomike

junomike

    Hubble

  • *****
  • Moderators
  • Posts: 18,845
  • Joined: 07 Sep 2009
  • Loc: Ontario

Posted 09 April 2020 - 12:51 PM

Nope.  A 100° eyepiece with a 25mm eye relief needs a 59.6mm eye lens (2.35")

tan0.5AF = 0.5LD / ER, where AF = apparent field, LD = lens diameter, and ER = eye relief.

 

The 26mm Meade has nowhere near that eye lens diameter.

https://www.meade.co...piece-26mm.html

Looks like MAYBE 35mm = 14.7mm eye relief.

 

Since most of the other 100° eyepieces have 14.5-15mm eye reliefs, I'd guess that was closer.

Now, if the actual apparent field is smaller, say 88-90°, then eye relief could be longer, but still not more than 20-21mm.

And the eye lens appears to be recessed several millimeters, which reduces the effective eye relief.

Don, Off the record, what's your estimation of the real AFOV?



#27 Starman1

Starman1

    Vendor (EyepiecesEtc.com)

  • *****
  • Vendors
  • Posts: 46,239
  • Joined: 23 Jun 2003
  • Loc: Los Angeles

Posted 09 April 2020 - 01:07 PM

Mike,

I don't have any experience with them.

The few people on CN who have looked into it found them to be around 88-90°.

That would be consistent with long eye relief, and would also augur well for improved edge performance.

But, in truth, I just don't know.



#28 junomike

junomike

    Hubble

  • *****
  • Moderators
  • Posts: 18,845
  • Joined: 07 Sep 2009
  • Loc: Ontario

Posted 09 April 2020 - 01:35 PM

Mike,

I don't have any experience with them.

The few people on CN who have looked into it found them to be around 88-90°.

That would be consistent with long eye relief, and would also augur well for improved edge performance.

But, in truth, I just don't know.

I'm more interested in the Field Stop measurement as I can better judge by that characteristic alone.



#29 faackanders2

faackanders2

    Fly Me to the Moon

  • *****
  • topic starter
  • Posts: 6,285
  • Joined: 28 Mar 2011

Posted 09 April 2020 - 03:23 PM

Apparent FOV 100°
Eye Relief 25mm (Much larger than 14.5mm)

 

Do you believe it?

 

I calculate that a 25mm of eye relief with a 100 degree AFoV requires a 42mm eye lens.  

 

I suggest you spend the $259, measure the AFoV, the eye relief, the eye lens diameter, the weight and report back.

 

jon

For only $259 was going to buy, but then when so many CN "experts" replied more like 90AFOV (than 100 AFOV) I changed my my to wait for more feedback.  This almost sounds like bad false advertising.  Wish magazines would do A-B unbiased testing of these supposedly same spec eyepieces.


Edited by faackanders2, 09 April 2020 - 05:03 PM.


#30 SeattleScott

SeattleScott

    Cosmos

  • *****
  • Posts: 8,114
  • Joined: 14 Oct 2011

Posted 09 April 2020 - 03:55 PM

Meade can advertise whatever they want. They already filed for bankruptcy so no one is going to bother suing them.

Ok that’s probably unfair. I do actually like Meade. But yeah I think they stretched the truth a little far here.

Scott

#31 faackanders2

faackanders2

    Fly Me to the Moon

  • *****
  • topic starter
  • Posts: 6,285
  • Joined: 28 Mar 2011

Posted 09 April 2020 - 05:07 PM

Meade can advertise whatever they want. They already filed for bankruptcy so no one is going to bother suing them.

Ok that’s probably unfair. I do actually like Meade. But yeah I think they stretched the truth a little far here.

Scott

Maybe bankruptcy is why they are selling so cheap.  Possibly short term below cost, just to get some cash for eyepieces already made.


Edited by faackanders2, 09 April 2020 - 05:08 PM.


#32 Starman1

Starman1

    Vendor (EyepiecesEtc.com)

  • *****
  • Vendors
  • Posts: 46,239
  • Joined: 23 Jun 2003
  • Loc: Los Angeles

Posted 09 April 2020 - 05:22 PM

Reviews of the Omegon Panorama II (the Omegon version of the eyepiece), in focal lengths shorter than 21mm, indicate:

--eye relief is insufficient for glasses (you can see maybe 80°), though no comments are available for the 21mm or 26mm.

--apparent field is closer to 90° than 100° (CN reviews, consistent with CN reviews of the Meade as well)

 

The MWA has 7 elements (not the 10 of the ES), but let's say it has a long enough eye relief for glasses (the 26mm, that is).

Wouldn't it be a decent companion for the 12mm and 17mm ES 92° eyepieces?

Everyone has been asking for longer focal lengths in that series.

 

So who is going to try one?


  • Astrojensen likes this

#33 Pat Rochford

Pat Rochford

    Mariner 2

  • *****
  • Posts: 263
  • Joined: 30 Sep 2008

Posted 09 April 2020 - 08:16 PM

So who is going to try one?

How about ten of us each send you $25.90 and we do ten different reviews?  After each of us gives our impression, you (being the honorable individual you seem to be) draw one of our names out of a hat and that person becomes the final owner.   


  • Procyon likes this

#34 RichA

RichA

    Surveyor 1

  • *****
  • Posts: 1,714
  • Joined: 03 Jun 2010
  • Loc: Toronto, Canada

Posted 09 April 2020 - 08:33 PM

https://www.meade.co...piece-26mm.html

 

Any thoughts on this eyepiece.  Wider TFOV than TV, APM, ES  2" eyepieces.

I just cannot take these eyepieces that have the bright colored rim around the periphery.  I've tried two Celestron widefield eyepieces and they both had it so I'm wondering if the

 

This is the ES100 20mm. How much different the 25mm is, does anyone know or can guess?

All it takes is for one surface or glass type to be different and you end-up with a whole new eyepiece, more or less.



#35 faackanders2

faackanders2

    Fly Me to the Moon

  • *****
  • topic starter
  • Posts: 6,285
  • Joined: 28 Mar 2011

Posted 13 April 2020 - 09:38 AM

Any CN member look through one yet?



#36 havasman

havasman

    Voyager 1

  • ****-
  • Posts: 11,025
  • Joined: 04 Aug 2013
  • Loc: Dallas, Texas

Posted 13 April 2020 - 09:45 AM

That hurt my brain.

In the end, I see the results were so-so.  I am still confident that 100 degree technology will advance and prices will fall in time.

That would be the APM HDC line of hyperwides. As far as I could tell from my time with the 20 & 13mm APM HDC's, the tech was the same. But the prices are much lower than TV and considerably lower than ES. In head-to-head use the 20mm was chosen over an ES100 20mm and the 13 bested even the ES100 14mm that I always thought the best of the ES100's.

 

None of the Meade hyperwide clones were ever in consideration here.


  • Msprinkle1 likes this

#37 25585

25585

    Cosmos

  • *****
  • Posts: 8,983
  • Joined: 29 Aug 2017
  • Loc: In a valley, in the UK.

Posted 13 April 2020 - 04:51 PM

Any CN member look through one yet?

It would have to be someone whose opinion & results others take seriously..... 



#38 25585

25585

    Cosmos

  • *****
  • Posts: 8,983
  • Joined: 29 Aug 2017
  • Loc: In a valley, in the UK.

Posted 14 April 2020 - 11:18 AM

Astronomics only stock up to the 21mm MWA. Not just them, other stores as well. Were there not many made?



#39 decep

decep

    Mariner 2

  • *****
  • Posts: 205
  • Joined: 19 Aug 2018
  • Loc: Griffin, Georgia

Posted 14 April 2020 - 03:25 PM

Astronomics only stock up to the 21mm MWA. Not just them, other stores as well. Were there not many made?

Probably due to the bankruptcy happening shortly after release.  Meade might have a warehouse full of them, but unable to get them to resellers.



#40 faackanders2

faackanders2

    Fly Me to the Moon

  • *****
  • topic starter
  • Posts: 6,285
  • Joined: 28 Mar 2011

Posted 14 April 2020 - 07:44 PM

Probably due to the bankruptcy happening shortly after release.  Meade might have a warehouse full of them, but unable to get them to resellers.

BANKRUPTCY MAY BE WHY PRICE IS LOW?



#41 Ahouseman

Ahouseman

    Lift Off

  • *****
  • Posts: 17
  • Joined: 27 Mar 2016
  • Loc: Washington, DC

Posted 20 April 2020 - 09:42 PM

I picked up the Meade 26mm MWA last week.  I don't have any other 100deg AFOV eyepieces to directly compare with, the closest being a 20mm Meade UWA 82deg.

 

I tested in a Zhumell Z8 8" (1200mm, f5.9) both with and without a GSO coma corrector/field flattener and a Explore Scientific 16" truss tube (1820mm, f4.5) with no coma corrector on a very clear night with excellent seeing.

 

Star drift test timing in the Z8 with no CC showed a TFOV of 2 degrees. In a perfect world which if all the numbers in the calculation are accurate (which they probably are not exact) and not accounting for distortion (which there has to be), is a AFOV of 92 degrees.

 

In all setups, stars in the center of the field appeared slightly sharper in the 26mm MWA than in the 20mm UWA, and I didn't notice any edge of field brightening.

 

In the Z8 with no CC installed, the outer 30% or so was a little out of focus, however not so much that it was super bothersome for just providing some extra field around the subject.

In the Z8 with the GSO CC/FF installed, stars out to almost the field stop (5%) were sharp.  The AFOV is so wide though it was completely unnoticeable unless I was specifically concentrating on a star right at the edge which would never happen in practice.

 

The experience in the ES 16" was a completely different story though:

The outer 30-40% of the field quickly became very out of focus and the edges so out of focus I couldn't tell there were stars,. unlike the views in the Z8, it was so distracting that I would consider it unusable.  I did not have the coma corrector/field flattener with me for testing though.

 

Hopefully the CC/FF will clean up the edges in the 16 as happened in the 8, because this EP was purchased specifically to provide the widest TFOV in the 16", however that test will have to wait for another night. 


  • HfxObserver, John Rogers, eros312 and 5 others like this

#42 HfxObserver

HfxObserver

    Apollo

  • ****-
  • Posts: 1,465
  • Joined: 12 Nov 2004
  • Loc: Canada

Posted 20 April 2020 - 11:46 PM

...how was the eye relief, 25mm?

 

Thank you,


  • 25585 likes this

#43 Ahouseman

Ahouseman

    Lift Off

  • *****
  • Posts: 17
  • Joined: 27 Mar 2016
  • Loc: Washington, DC

Posted 21 April 2020 - 07:52 AM

just measured with the eye piece pointed at a window and piece of paper.  sharpest focus was right about 22mm back from the lens (which is curved, so +/- a couple mm).


  • eros312 and Procyon like this

#44 HfxObserver

HfxObserver

    Apollo

  • ****-
  • Posts: 1,465
  • Joined: 12 Nov 2004
  • Loc: Canada

Posted 21 April 2020 - 09:27 AM

Thank you! I wonder if it's enough for us eyeglass wearers to get the full field with our glasses on and the eyecup rolled down, any way you can test this?

 

 

 

Thanks again!



#45 Ahouseman

Ahouseman

    Lift Off

  • *****
  • Posts: 17
  • Joined: 27 Mar 2016
  • Loc: Washington, DC

Posted 21 April 2020 - 10:05 AM

with the cup rolled down and some sunglasses on, yes, i could.



#46 HfxObserver

HfxObserver

    Apollo

  • ****-
  • Posts: 1,465
  • Joined: 12 Nov 2004
  • Loc: Canada

Posted 21 April 2020 - 10:46 AM

That is very interesting, this would make a high-mid-20mm eyepiece with enough eyerelief for eye-glasses finally available.

 

Any idea of the weight of this eyepiece?

 

Thanks again,



#47 Ahouseman

Ahouseman

    Lift Off

  • *****
  • Posts: 17
  • Joined: 27 Mar 2016
  • Loc: Washington, DC

Posted 21 April 2020 - 11:06 AM

795g / 1lb 12oz weight


  • HfxObserver and Procyon like this

#48 Procyon

Procyon

    Fly Me to the Moon

  • *****
  • Posts: 6,561
  • Joined: 23 Feb 2009
  • Loc: Eastern Canada

Posted 21 April 2020 - 01:19 PM

For only $259 was going to buy, but then when so many CN "experts" replied more like 90AFOV (than 100 AFOV) I changed my my to wait for more feedback. This almost sounds like bad false advertising. Wish magazines would do A-B unbiased testing of these supposedly same spec eyepieces.


259 for a 90 degree 26mm might not be so bad.
  • OneGear likes this

#49 Starman1

Starman1

    Vendor (EyepiecesEtc.com)

  • *****
  • Vendors
  • Posts: 46,239
  • Joined: 23 Jun 2003
  • Loc: Los Angeles

Posted 21 April 2020 - 01:54 PM

259 for a 90 degree 26mm might not be so bad.

Exactly this.

It could be a super-lightweight companion to the ES 92s.


  • OneGear likes this

#50 Astrojensen

Astrojensen

    Voyager 1

  • *****
  • Posts: 13,048
  • Joined: 05 Oct 2008
  • Loc: Bornholm, Denmark

Posted 21 April 2020 - 01:57 PM

Exactly this.

It could be a super-lightweight companion to the ES 92s.

IF the edge performance is good... First reviews so far aren't so hot.

 

 

Clear skies!
Thomas, Denmark




CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.


Recent Topics






Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics