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[Ben the Ignorant]

Hey, folks!

AST Optics is having a sale on several eyepieces; check that:

https://www.astromarket.org/koopjeshoek-5/mega-wide-angle-eyepiece-5mm-new?language=en

https://www.astromarket.org/koopjeshoek-5/68-series---16mm---125-5?language=en

https://www.astromarket.org/koopjeshoek-5/super-wide-angle-70-swa-12mm686531243105-5

https://www.astromarket.org/koopjeshoek-7/super-wide-angle-70-swa-12mm686541-7

The 70° eyepieces are only four-element thingies but at 25€ it would be easy to find a decent use for them, especially in slow telescopes, or homemade finders. The Explore 16/68 is barely more expensive than the 24/68 was during its own sale (which might still be ongoing in some stores), and the large 100° Meade is tagged less than 150€, my personal upper price limit for an 82° eyepiece.

If I didn't already own a 5mm Myriad I would seriously consider buying it. Is it true - asking people who actually looked through one - that these Meade's provide only 90 or so degrees? Or is it just Meade bashing?

[John]

Here are some reports on the Meade MWA's. These folks normally post sensible stuff on their CN forum so I don't think they are just having a go at the brand:

https://www.cloudynights.com/topic/486454-15mm-meade-mwa-is-in/

 

[Ben the Ignorant]

I read the CN thread; one guy could see two stars separated by 97° in the eyepiece, so the real field has to be a tad bigger than that. Others say it's less, but they don't agree on the distance from eye to eyepiece. If they force themselves to put their eye 20mm above the lens because data on paper says 20mm, they are losing a few degrees.

I know Meade takes flak sometimes, but I don't think they could be so unaware of their own product's specs. And if the thing is only 88°, well it's the cost of an 82° eyepiece, but with 6 more degrees! However, I don't believe that, measured results are always more believable, and the measured 97 degrees-plus seems more realistic than mere opinions.

Blackouts stop when one gets used to a new eyepiece, that also looks like a non-issue.

[John]

5 minutes ago, Ben the Ignorant said:

I read the CN thread; one guy could see two stars separated by 97° in the eyepiece, so the real field has to be a tad bigger than that. Others say it's less, but they don't agree on the distance from eye to eyepiece. If they force themselves to put their eye 20mm above the lens because data on paper says 20mm, they are losing a few degrees.

I know Meade takes flak sometimes, but I don't think they could be so unaware of their own product's specs. And if the thing is only 88°, well it's the cost of an 82° eyepiece, but with 6 more degrees! However, I don't believe that, measured results are always more believable, and the measured 97 degrees-plus seems more realistic than mere opinions.

Blackouts stop when one gets used to a new eyepiece, that also looks like a non-issue.

Why not buy one and report back on what you think of it ?

 

 

[Ben the Ignorant]

Why not spend your own money if you think people should buy stuff they don't need just to check one spec? 

I don't print money in my basement, and I see no reason to doubt Meade when they say their eyepiece is a 100°. First, only one or two guys who did no measurements say the field is 88° when the South Korean guy measured a little more than 97°. Second, this is probably a clone of other 5mm 100's, so the specs can't be that different. Maybe a slight change in the frontal Barlow/Smythe lens that would explain the small difference in resulting focal length between the 4.7mm or 5.5mm and this 5mm, I'm not sure.

Third, in this time of hypersensitive lialibity claims, no business is going to issue false and easily disprovable specs just to be embarassed and/or sued. Meade and their chinese factory have the technical ability to provide and verify 100° fields; I see no motive to doubt that, but a random poster in a forum can claim anything and does not have to prove it. Besides, Cloudy Nights as a whole is reputable, but I have seen some nonsense there, too, written by unexperienced people.

Fourth, I own three Meade/Maxvision eyepieces which perform very well, and within specs. I trust this is really a 100° eyepiece.

[Ruud]

I trust SGL. They are noble and enlightened.

[John]

4 hours ago, Ben the Ignorant said:

...but I have seen some nonsense there, too, written by unexperienced people.

 

So have I. The ones who didn't find fault with the Meade MWA's seemed to lack experience. Those who noticed the issues and were able to quantify them included some of the most experienced posters on that forum. I know who I'd go with .....

[laowhoo]

 

I like this follow up thread better...and the OP is not relenting. Also telling(?) is the Meade reps blunder.

https://www.cloudynights.com/topic/494520-meade-add-misleading/

[Ben the Ignorant]

Tele Vue's Ethos 3.7mm and 4.7mm have a 110° field unlike the other Ethos that have a 100° field. Same for my 3.5mm and 5mm Myriads, their field is 110° across unlike my 9mm, which is a 100° like the rest of the Myriad line.

If someone unaware of that compares a 110° Ethos to a 100° Meade, they will think Meade cheated. The guy who started the thread says precisely that: he put an Ethos to his eye, and the Meade to his other eye, saw a field smaller by about 10%, and began his rant.

[John]

I owned the Ethos SX 3.7mm and 4.7mm for around a year so I'm familliar with those. The Myriads I reviewed for the forum a while back:

https://stargazerslounge.com/topic/236613-skywatcher-myriad-100-110-degree-apparent-field-eyepieces/

I'd be surprised if an observer didn't know that these were 110 AFoV eyepieces - it's etched quite clearly on the barrel of the eyepiece in bright green or silver lettering, depending on the brand.

 

[Ben the Ignorant]

I'd be surprised if Meade didn't know their eyepiece's field.

[John]

8 minutes ago, Ben the Ignorant said:

I'd be surprised if Meade didn't know their eyepiece's field.

I wouldn't. They don't make or design stuff like eyepieces these days. To quote one of the CN posters:

"But let's face it.  Meade is a brand, not a technology company these days.  I doubt Meade had any hand in designing or specifying this eyepiece.  Rather instead I suspect they needed a "100" to be able to compete with former supplier and now rival JOC, so they shopped China, Inc., for an off the shelf "100-degree" design they could buy cheaply and mark up for a handsome profit.  They trusted their supplier's specifications most likely without doing any independent verification of specs.  Which is exactly what rebranders do."

I suspect this is a reasonably accurate assessment.

 

[Ricochet]

17 hours ago, Ben the Ignorant said:

Fourth, I own three Meade/Maxvision eyepieces which perform very well, and within specs. I trust this is really a 100° eyepiece.

I believe that the Meade branded eyepieces you own were all manufactured by JOC (Explore Scientific) for Meade. I suspect the new MWA line are manufactured in the Sunny Optical factory given that Meade and Sunny Optical have been merged. As such the quality of the old JOC eyepieces cannot be used as a guide to the quality of the new eyepieces that may come from another manufacturer.

5 hours ago, Ben the Ignorant said:

If someone unaware of that compares a 110° Ethos to a 100° Meade, they will think Meade cheated. The guy who started the thread says precisely that: he put an Ethos to his eye, and the Meade to his other eye, saw a field smaller by about 10%, and began his rant.

The user clearly states that he compared a (100°) 13mm Ethos to a 15mm MWA. If they are both ~100° there should be no obvious difference.

Having said that, I have no experience with any of the MWA line and the linked threads are lacking in actual measurements. In two threads all I see is one figure of 97°. However, this is not an actual measurement. The only measurement is an estimate of a TFoV of 0.68° based on the the separation of two stars. The 97° is then calculated using M = Ft / Fe and M = AFoV / TFoV, however, this second equation is only a small angle approximation of angular magnification and inaccurate for any wide angle eyepiece. Instead we should use M = tan(Afov/2) / tan(TFoV/2), which gives a minimum AFoV of 81° (I suggest minimum because the two stars must be separated by less than the TFoV in order to be seen), which is quite some way from the advertised 100°.