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Edmund Plossls Arrived - First Light!

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#1 BillP

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Posted 14 April 2010 - 07:42 PM

I previously had the 28mm Plossl and have been enjoying it very much. Wonderful color rendition of stars, velvet background, very comfortable to use. I have actually been reaching for it more often than my 24 Pan and prefer its view to the 32mm and 21mm TV Smoothside Plossls I have. So based on that experience decided to grab them all for a few months of evaluation :grin:

In the picture, I also show the 28mm RKE and the much older 1-1/8" pre-RKE. Upon examination of the FOVs of the 28mm thru 12mm, they are just slightly larger than the AFOV of the TV Plossls. Looking closer at the 8mm "Plossl" it's actually a compound eyepiece with an integrated group of elements in the barrel - pictured is the underside of the 8mm next to the 12mm, then the 8mm separated into its two halves. Doing a quick eyeball test on the 8mm it's AFOV is a good bit larger than the TV Plossls and slightly less than the AFOV put up by the 24 Pan. So based on the eyeball test I would say its AFOV is near to 60 degrees. Later in the week will do a bench test to measure the AFOVs and post then. Coatings look simple (i.e., single-coat) but can't be sure. Lens edges in typical Edmunds style are not blackened. By the imprint on the box, these are made in China...and by the Edmund website made *exclusively* for Edmunds. Anyway, hope to give them a spin tonight ... right now as a matter of fact :grin:

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#2 BillP

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Posted 14 April 2010 - 09:04 PM

OK...took them out for a first spin in the TSA-102 and compared them against my TV Smoothside Circle-NJ Plossls.

Overall, the eye relief is a little better with the Edmunds. Most times the TVs required my face to be in contact with the housing to see the entire AFOV and with the Edmunds I could be just lightly touching or not at all. With the 8mm is was plainly more comfortable and did not have to be in contact at all with the Edmund.

FOV in the Edmunds showed a little field curvature at extreme edge. Not much though and if I focussed for the edge the center still looked sharp. The TV did not show this. Also noted that in many of the TVs the region next to the field stop presented slightly darker as if some vignetting was going on. Hard to see but gave that impression. The Edmunds did not show this and has a nicely uniform FOV to the edge and the background FOV also appeared slightly richer than in the TV.

As I looked at open clusters and some doubles, it was obvious that the orange stars in the FOV were coming through better in the Edmund. Colors were just a little richer and enough so to have it catch my eye wereas this was not happening with the TVs.

Scatter seemed more or less on par between them, with maybe the slightest of edge going to the TV.

Star point size seemed as well rendered in each with neither showing better than the other.

Saturn...this was niiiice tonight as a very steady atmosphere so was treated to great views up thru 250x. Overall, the Edmunds bested the TVs on Saturn, both without Barlow and with. Polar shadings were more pronounced, the Cassini division was much easier to see at the out edges of the rings, and the Crepe Ring was clearly more evident. Fianally, Rhea was plainly more visible with direct vision thru the Edmund vs the TV. As a counterpoint though, faintest visible direct vision stars in clusters did not seem to have advantage in one eyepiece over the other. But for some reason with Rhea it was obviously easier to see in the Edmund -- perhaps a byproduct of the way scatter was occurring around Saturn? Don't know.

Well that's it for now. The 8mm is a real gem of an eyepiece from this 1st look. Eye relief was very nice and the wide around 60 deg AFOV was quite pleasant. Using it very much reminded me of my Pentax 8.5mm XF experiences. On the down side for the 8mm only, was that when a bright star was just outside the field stop there is a momentary flare across the FOV. Very minor but there. With Saturn also detected a very very dim reflection at some points in the FOV. Was quite difficult to see and very much lived up to the term "ghost." So some very minor light artifacts with the 8mm, but still they did not detract from just how well it was performing as a planetary. Nice eyepiece...also more expensive then the rest at $69. But still a steal for that price IMO.

#3 Daniel Mounsey

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Posted 14 April 2010 - 10:55 PM

WOW! Bill that's fantastic and I still love Televue plossls too. You sure don't waste any time lol! It would really be great to get your impressions on the actual AFOV. Interesting also how the glass seems pretty snug up against the field stop. Yea, eye relief is actually quite good on that 8mm and I'm surprised it was from China. I haven't done the research on this eyepiece yet in fact I was not even aware it existed until my friend asked me if I'd like to check out his new eyepieces. Saw the 8mm and was shocked. Maybe Mike Hosea may have an idea on the design. I'm surprised Edmund doesn't have the correct specs on the AFOV but obviously you saw what I meant. Get back to this forum and let us know the AFOV.

#4 Ed Kessler

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Posted 15 April 2010 - 05:44 AM

Bill,

I assume from your comments that the tone of the Edmunds was "cooler." Is that correct?

Are the barrels painted or anodized?

#5 BillP

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Posted 15 April 2010 - 08:19 AM

Daniel - will do the exact measures on the AFOV maybe this evening. At some point, probably after NEAF, I will disassemble them all to blacken the lens edges, so will know the exact lens groupings and design then. Or can ship it off to Mike to do :grin:

Ed - I didn't note any tonal differences, or look for them actually. I did see though that orange-red stars were more prominent in the FOV of the Edmund as opposed to the TV. I did not note any tone differences on Saturn, just that the contrast seemed a little better as things like the Cassini and Crepe stood out more prominently. I think the barrels are annodized with a satin textured finish. I don't think it is paint. Will give it a closer view this evening.

I am curious about the Barrel lens group on the 8mm. If the threads are the same then would be interesting to see how that grouping affects the other Plossls in the line if I exchange barrels.

#6 m. allan noah

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Posted 15 April 2010 - 11:18 AM

I am curious about the Barrel lens group on the 8mm. If the threads are the same then would be interesting to see how that grouping affects the other Plossls in the line if I exchange barrels.


Would also be interesting to see if a spacing ring between the two halves would increase the mag without some increase in aberrations...

allan

#7 bcuddihee

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Posted 15 April 2010 - 11:51 AM

Jim your observation seem to be on par with mine on the 28's, the 21's and the 15's. These are just plain great IMO, and at around 39.00 US, a fantastic buy. I have pairs of these and use them in bino's.
bc

#8 BillP

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Posted 15 April 2010 - 11:58 AM

Hey...that's an interesting thought...like the fine tuning rings for the Hyperions.

#9 skyjim

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Posted 15 April 2010 - 08:47 PM

Hi Bill, I,ve been looking for a nice set of plossls and been looking real close at the Edmunds and I think also AT has some that look like the sterlings. I wonder how the ER is on the Edmund plossls, they dont list much on there web site. From your reveiw they seem very good compared to the TV's which some hold as a gold standard.
Maybe will run into you this weekend at Neaf, I'll be there early saturday morning, maybe a new refractor might find its way home this weekend.
Jim :grin:

#10 leonard

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Posted 15 April 2010 - 11:09 PM

Hi Bill ,

Do you still have your 12.5mm sterling plossl ?
I know its somewhat different in FL but maybe close enough to gain some insight between the two. I would be interested in your take between the Edmmund 12 and the Sterling 12.5.

Leonard

#11 BillP

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Posted 16 April 2010 - 08:03 AM

Unfortunately not. The Sterlings (aka now also Astro-Tech High Grade Plossl) we also quite close in performance to the TVs. I recall noting only the very very slightest less performing on faintest stars over the TV. But they also have the larger AFOV which makes them unique. Again, wish the line would do something to fill the HUGE gap it has between the 6mm and 12mm :(

#12 BillP

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Posted 16 April 2010 - 08:36 PM

I finally had some time, so bench measured the Edmund 8mm "Wide Field Lens" which they group with the other Plossls of the line.

Eye Relief = 8.5mm (from housing), 9.5mm (from lens surface)

AFOV = 59.7 deg

Eye Lens Diameter = 13.6mm

#13 orion61

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Posted 26 November 2012 - 04:57 PM

Jim your observation seem to be on par with mine on the 28's, the 21's and the 15's. These are just plain great IMO, and at around 39.00 US, a fantastic buy. I have pairs of these and use them in bino's.
bc

I have basically switched to Edmunds oeriod.
being old school I dont NEED 80 degrees, why krank your neck just to look around things..LOL,
They are very fine in bino viewers especially the 15mm
I love the entral sharpness and whatever coatings they are useing are great!
Spend the money on the scope not the eyepieces.

#14 jrbarnett

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Posted 26 November 2012 - 06:46 PM

Bill:

How do the Edmund Plossls stack up to your Sterling Plossls?

Regards,

Jim

#15 Sarkikos

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Posted 26 November 2012 - 06:49 PM

Talk about resurrecting a thread... :grin:



#16 Sarkikos

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Posted 26 November 2012 - 06:59 PM

The only Edmund Plossls I've tried were a pair of the 28mm for binoviewing. I only binoview bright planets and the Moon, so I can't say how they are for DSO. But I compared the pair - for Jupiter in particular - against pairs of RKE 28, UO VT 25, TV Plossl 25, BGO 18, and LER 18. I screwed various OCA's on the neck of the binoviewer to mix up the magnifications a little, and give them all a fighting chance.

I didn't see that the Edmund Plossls stood above the rest for viewing Jupiter. I preferred the BGO's, with the TV Plossls a close second.

Recently I sold one of the Edmund Plossl 28's. I still keep the other in my deep sky case.

Mike

#17 Sarkikos

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Posted 26 November 2012 - 07:05 PM

IIRC, the Edmund Plossls have a neutral to cool tone. I'm not surprised that Bill said they did well for Saturn versus the TV Plossl. The Edmund Plossls might also be good for lunar observation. TV Plossls are a warmer-toned eyepiece, making them better for Jupiter and maybe Mars.

Bill also said that the color rendition of stars was better for the Edmund Plossls over the TV Plossls. Again, not surprising if the Edmunds are neutral-to-cool and the TV's are warm. (IME & IMO, the tone of an eyepiece does have an affect on the appearance of various objects.)

When I was comparing those bino pairs, I was mostly concerned with Jupiter. Maybe I should have kept a pair of the Edmund Plossls for binoviewing Saturn and the Moon ... :thinking: On the other hand, my RKEs, Paradigms, Brandons and LERs are good for those. Why over do it?

:grin:
Mike

#18 BillP

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Posted 26 November 2012 - 08:22 PM

Bill:

How do the Edmund Plossls stack up to your Sterling Plossls?

Regards,

Jim


Sterlings are brighter, and of course have the wider 55-57 deg AFOV. The 28mm Edmund Plossl is sort of like a well behaved version of the 28 RKE. Very nice. Edmund does not say the coatings used on the Plossls, but I suspect they are single coated.

#19 jrbarnett

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Posted 26 November 2012 - 08:27 PM

Thanks Bill.

How would the Sterlings work at f/5?

Regards,

Jim

#20 Sarkikos

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Posted 26 November 2012 - 10:14 PM

Bill,

Sterlings are brighter, and of course have the wider 55-57 deg AFOV. The 28mm Edmund Plossl is sort of like a well behaved version of the 28 RKE. Very nice. Edmund does not say the coatings used on the Plossls, but I suspect they are single coated.


So Sterlings for deep sky, Edmund Plossls and RKEs for Saturn and Moon? And RKEs for the "floating in space" trick, of course.

Mike

#21 bcuddihee

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Posted 27 November 2012 - 09:19 AM

Mike that's the way I see it. The Edmund plossls I keep for Jupiter, which are the best I've seen for Jupiter in my C8, ans Saturn. They are really amazing little ep's.
bc

#22 Sarkikos

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Posted 27 November 2012 - 10:07 AM

Brian,

Since Edmund Plossls are neutral-to-cool, I would think they'd be better for Saturn and the Moon than for Jupiter. The received wisdom is that warm eyepieces, like the TV Plossls, are better for Jupiter. That more or less agrees with my experience. I've found that I like Jupiter either with TV Plossls unfiltered or with a neutral-to-cool eyepiece (e.g., BGOs) filtered by a Baader Moon & Sky Glow.

Mike

#23 Sarkikos

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Posted 27 November 2012 - 10:22 AM

I just ordered the Sterling 12.5, 17 and 20 to accompany my Sterling 25, for deep sky and grab-n-go. I've put off that move for about a year, at least. But after rethinking the Sterlings vs TV Plossls, and the best use for these different Plossls, and also having sold many of my other Plossls, I finally went for the other three Sterlings. I also intend to pick up used TV Plossls as they come up - especially the smoothies - if the price is right.

But I'm still on the fence about these Edmund Plossls. I don't think I'll give up the 25mm I have, but I'm not sure I'll buy any others. :shrug: I always think about the intended object of an eyepiece, as well as which of my scopes the eyepiece will work best in. There is still some uncertainty...

Mike

#24 Sarkikos

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Posted 27 November 2012 - 11:20 AM

Another sticking point for me is the apparent simple coating (one coat?) on the Edmund Plossls.

I'm starting to think more and more that fully multicoated optics - as long as they are applied "optimally" - are virtually always better than simpler coatings. Simpler coatings tend to keep the eye from seeing all that is there to see in the object. If we want to selectively filter the image, isn't it better to use a filter? True, eyepieces can be warm or neutral or cool toned, but that doesn't prevent the eyepiece from being fully multi-coated. Aren't the TV Plossls fully multi-coated, despite their "coffee" tone? Don't even the Brandonistas tend to prefer more modern coatings on the newer Brandons rather than the older simpler coatings?

Mike

#25 astrodon

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Posted 28 November 2012 - 12:34 AM

I certainly prefer the coatings on the modern brandons to those of the Chester Brandon eyepieces with the bare steel barrels. I get images with greater throughput and contrast. I did have a older vintage Vernonscope 12.7mm (1/2") wide angle with the older Vernonscope coatings and it was nearly at the level of the most modern coatings on the Brandons I currently have. In fact it is my understanding that the modern coatings are still single-layer, not multi-coatings.






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