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EdZ
Professor EdZ
Reged: 02/15/02
Posts: 14732
Loc: Cumberland, R I , USA42N71.4W
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take notice in that link to the differences in opinions of performance.
edz
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Teach a kid something today. The feeling you'll get is one of life's greatest rewards.
member#21
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BobinKy
Carpal Tunnel
Reged: 04/27/07
Posts: 1683
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EdZ...
How right you are. I posted the previous link because of its diversity of opinions about the ED/nonED versions of a specific model. I think discussion and different opinions make online forums worth the time and effort to participate and keep up with the topics.
. . .
Now, regarding the ED/nonED question, I think we cannot really do the topic justice without entering the discussion of color sensitivity among various observers. Simply put, how much do differences of color sensitivity by individual observers affect the decision to purchase an ED or nonED model? If the observer's eyes are sensitive to one or more colors, maybe the ED binocular may be worth the premium price. On the other hand, if the observer has limited sensitivity to colors, the nonED binocular may see just as much as the ED model.
EdZ, I know you discussed color sensitivity differences among observers. However, here is a link from another forum with links to medical research that also discuss the many nuances of color sensitivity. I direct any interested reader to the links in my first post of the thread in the link below--(1) How we see colors
(2) Intertwining of color sensitivity with the other senses
(3) Possible gender differences in color sensitivity. Here is the link: What determines our color sensitivity as looking through bins? .
The link also discusses brand manufacturer bias toward specific colors, as well as atmospheric influences upon brand manufacturer's color rendering. Some of the participants in the link have actually done tests (with photos) of brand manufacturing bias.
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Bob
38°N
Edited by BobinKy (07/03/09 08:00 AM)
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EdZ
Professor EdZ
Reged: 02/15/02
Posts: 14732
Loc: Cumberland, R I , USA42N71.4W
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Quote:
Now, regarding the ED/nonED question, I think we cannot really do the topic justice without entering the discussion of color sensitivity among various observers. Simply put, how much do differences of individual color perception affect the decision to purchase an ED or nonED model?
I addressed that issue in my report. It's not simply human perception (which by the way we cannot quantify, so I won't bother discussing), but it is color bias in the correction of the instrument. How many users hate the Fujinon FMT-SX becuase of the broad blue false color fringe, and yet how many does it not bother at all? That individual color perception is not relegated to ED/nonED choices. But as I reported above:
Quote:
So, having two binoculars of apparently the same quality, why is it one binocular can look so much better than another? Refer to the portion above about bias. Color correction of two different achromat scopes (two different binoculars) can be biased towards the red end or the blue end of the spectrum, but still be equal. Some people are more turned off by red CA and others more by blue CA. Some people (IIRC, older people with smaller pupils) are less sensitive to blue and may not even see the full extent of blue CA, and therefore find a blue CA biased instrument seems to be without color. Yet it may have exactly the same color error as another biased towards the red, that, to the same eyes, seems to have lots of false color.
This brings up a good point. This issue on bias and the following I answered above just this moring on lateral color
Quote:
Every wavelength of light has a different focal length. Since a lens presents rays across not a flat plane at the focal point, but a curve, if it were corrected to have CA minimized at the center, it will still present the focal point of the same wavelength rays at a different position to the eyepiece as you move further off-axis. An eyepiece cannot focus across all the points of a curve at the same time, so while focused on any given point, some other point must be out of focus. The presence of lateral color is showing the amount of off-axis curve that cannot be accomodated by the eyepiece, focal plane junction.
I'll assume it is for this reason, often the CA correction in a doublet is corrected at the position 70% off axis. This at least helps minimize this effect. Perhaps a lens design that moves the CA correction away from the 70% off-axis position inward is one that shows considerably greater lateral color. But this is now considerably off-topic to the discussion of ED glass. This is lens design.
Take a moment and think about both these issues. They can both be accommodated very well in either an ED binocular or a non-ED binocular. BUT more importantly, neither one really is dependantt on ED glass. So here are two examples of how someone can perceive that the binocular marketed as ED glass so much improves the view, yet the reason for the improved view might have nothing to do with ED.
There are some not so expensive glasses that can be employed in design to market as what may be called ED binoculars. Not all of them really give all the improvements that may be perceived by the user. Few users really expend the effort to actually quantify what causes results. If you read clearly what I summarized in my very first post, you may notice that one of my points is that ED glass may not be responsible for all that is perceived. Isolating cause and effect is not so easy. Perception can often be mis-perception.
edz
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Teach a kid something today. The feeling you'll get is one of life's greatest rewards.
member#21
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BobinKy
Carpal Tunnel
Reged: 04/27/07
Posts: 1683
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Post deleted by BobinKy. If interested, please see my next post below.
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Bob
38°N
Edited by BobinKy (07/03/09 08:01 AM)
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gmazza
super member
Reged: 03/10/09
Posts: 102
Loc: RS, Brazil, 29S 51W
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Quote:
Few users really expend the effort to actually quantify what causes results.
In a post months ago we all were greatly benefited from your measures of exit pupil ilumination profile of 3 premium binoculars.
Variable subjective opinions require objective testing.
If few people bother to quantify by perception the color differences of the different solutions exposed above, even less to measure it in quantitative and qualitative data. Just by testing is possible to determine if a precise measure of the spectrum delivered by different areas of exit pupil could prove if a ED design is better than stopped one (or other solutions already mentioned). As already stated there are different glasses for use in ED merchandized lenses, so if a quality non ED is better than ordinary ED is just subject to testing.
I don't know about the instruments and method to do this.
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Oberwerk Ultra 10X50
Garrett Signature 15X85
Edited by gmazza (07/02/09 10:29 AM)
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ronharper
Pooh-Bah
Reged: 02/14/06
Posts: 1276
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Sorry for sending things off topic, Cloudy Days would be the place for the lateral CA issue. CA is not much of a problem for astronomical use of typical small through medium large binoculars, and doesn't warrant expensive "solutions".
However, the finest and most expensive Binoculars made shouldn't be barred from discussion. There are apparently some pretty rich dudes here! Not me, dang it.
Ron
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gmazza
super member
Reged: 03/10/09
Posts: 102
Loc: RS, Brazil, 29S 51W
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Quote:
CA is not much of a problem for astronomical use of typical small through medium large binoculars, and doesn't warrant expensive "solutions".
I think this is one reason of the previous shifting of opinions to daytime use. The kind of CA discussed is more noticeable at:
1. high magnifications
2. Astrphotography
3. lateral CA.
Astronomy binoculars are low magnification, not used for astrophotography, this left only the lateral CA for discussion.
Lateral CA is more a issue in Miky Way scan, it is almost negligible in steady, framed objects at such low magnifications.
We could even speculate about the use of doublers, thus increasing magnification and making the aberrations more noticeable, if the ED models are more resistant to boosted magnification or not, but in daily practice, and even more in astronomy, I have seen very few reports of doubler use.
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Oberwerk Ultra 10X50
Garrett Signature 15X85
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BillC
on a new path
Reged: 06/04/04
Posts: 2237
Loc: Washington, USA
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It is too bad that we are SOOOOO trusting that with take popular buzzwords to be of GREAT value.
WE take "ED Glass, BaK4 prisms, semi-apochromatic, Multi-coated . . ." to mean better viewing. Not one word is said about the dozens of OTHER features that go into making a good instrument.
Because "aspheric lenses" are used in a particular instrument, does it mean the aspheres were calculated correctly, make correctly, or made with the composition of the OTHER elements having been taken into consideration.
Let's get REAL here. Good binoculars are made from the sum of their design concepts and parts--not the coolness of their buzzwords!
Cheers,
Bill
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William J. Cook, Chief Opticalman, USNR-Ret.
Founding Editor, Amateur Telescope Making Journal
20-year vet. of Captain's Nautical Supplies, Optics Dept. Mgr.
Optics Machanic, WG11-3306, Ft. Lewis, Tacoma,WA
Yata, Yata, Yata . . .
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KennyJ
Reged: 04/27/03
Posts: 12908
Loc: Lancashire UK
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Thanks for that reminder , Bill !
Another thing I've noticed with regard to colour perception is that I notice a considerable difference between what I see through my right eye and what I see through my left .
Kenny
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If everyone is thinking the same thing , no-one is thinking - General George S.Patton
Zeiss 7 x 42 BGAT
Captain's Helmsman 7 x 50
Nikon 10 x 42 Superior E
Swift Audubon Kestrel 10 x 50
Helios 15 x 70 Observation
Strathspey 20 x 90
Televue 76 APO
Zeiss 85 Diascope
Helios 102 f5 refractor
Various eyepieces barlows tripods mounts etc.
Panasonic Lumix DMC - TZ5 digital camera
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Pinewood
scholastic sledgehammer
Reged: 12/07/04
Posts: 825
Loc: 40.77638º N 73.982652 W
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Kenny,
It is the same with me: one eye shows more saturated colour. I have sent you a PM about a possible cause.
Happy observing,
Arthur
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Bread is not enough. We demand circuses!
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Wes James
Post Laureate
Reged: 04/12/06
Posts: 3459
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Quote:
It is too bad that we are SOOOOO trusting that with take popular buzzwords to be of GREAT value.
I suppose that could be blamed upon the constant heap of advertising that is heaped upon us over an entire lifetime-
Quote:
WE take "ED Glass, BaK4 prisms, semi-apochromatic, Multi-coated . . ." to mean better viewing. Not one word is said about the dozens of OTHER features that go into making a good instrument.
That's probably because those OTHER features are not as easy to quantify as "BAK-4", "ED", "APO", etc. Advertising dictates that we have to have buzzwords that people can quantify/identify with. The "OTHER" things that are not as easy to quantify come- silently assumed with a brand name or price tag- or reviews on wonderful forums such as this.
Mechanical quality, optical quality, longetivity- or a company's reputation is not so easy to quantify with a buzzword.
Quote:
Because "aspheric lenses" are used in a particular instrument, does it mean the aspheres were calculated correctly, make correctly, or made with the composition of the OTHER elements having been taken into consideration.
Let's get REAL here. Good binoculars are made from the sum of their design concepts and parts--not the coolness of their buzzwords!
Goes without saying, I think- but good to be reminded of every now and then.
Nice to see you here again, Bill- hope you're doing well! We miss you when you're not around.
Wes
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moynihan
Carpal Tunnel
Reged: 07/22/03
Posts: 1605
Loc: Wisconsin
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Quote:
...
I could look at a crow against a bleak, winter's sky with the 10x ED bin and not see any color fringing on axis and even a bit off axis. ....Turn those ED bins on a Yellow Finch or a Cedar Waxwing or on colorful bed of flowers and be prepared for a "Wow" moment.
I would have to agree with that from my limited experience with ED binos.
I have the Swift Audubon 8.5x44 in three flavors, regular, (older non-armoured), ED, and roof.
The above quoted text is true, for me. Of course, as EDZ pointed out, other factors may be at play between ED/non-ED models, even from same manufacturer/brand. Also, there can be variation within copies of the same model...
But i should add, that regarding my three binos mentioned above, the ED difference is very clear (for me, your mileage may vary) when looking at for example the rim of the moon, also.
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"Gosh, you've... really got some nice toys here"
Dual mount/ambient temperature Hominid Widefield Photon Collectors®
Pleistocene™ ½ watt Wetware Integration Unit.
entia non sunt multiplicanda praeter necessitatem
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Pinewood
scholastic sledgehammer
Reged: 12/07/04
Posts: 825
Loc: 40.77638º N 73.982652 W
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Quote:
However, in an actual color extinction test at twilight, the SE outperformed the EII by about 8-10 minutes, perhaps because of the slightly larger aperture or more efficient light transmission.
In daylight, the EII looks "brighter" to my eyes.
Hail B'rock son of Gr'lka,
If you were testing the 8x SE and EII, in Cloudy Valley, I would be surpised that 2 mm. difference in aperture would make an 8-10 minute difference in twilight colour distinction. In Copenhagen, or another spot, at a high latitude, such a conclusion would make far more sense.
Happy observing,
Arthur
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Bread is not enough. We demand circuses!
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Gordon Rayner
scholastic sledgehammer
Reged: 03/24/07
Posts: 970
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In #3194486, , we read " ..... often the CA correction in a doublet is corrected at the 70% position off axis..."
It has been a while since I read about lens design, but I am recalling that the 70% is at the ray height 70% of the lens radius, and is for rays parallel to the lens axis, called paraxial, and is not a correction chosen for field rays.
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NDfarmer
member
Reged: 04/02/09
Posts: 24
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This thread has been very interesting in its discussion of the newer ED products. Many are binoholics here, not all are into astronomy, but birding, hunting and everything else. One conclusion that can be drawn is that the newer ED bins coming out mainly China certainly impress. With color, brightness, clarity and many of the basic things by
which all binoculars are judged. I am just waiting for the smoke to clear before making my first pick into the large and growing choice comning into view. Right now the ZenRay Ed with new dielectric coatings in 7x36 has my interest, will be out soon but who knows, maybe if I wait till fall there will be something else. In the meantime I'll use my Nikon 8x32 SE, and 10x42 SE, the Swar. 8.5x42 EL, so I won't be wanting or needing anything better. (Brocknroller, keep writing, Klingon, you keep me smiling!)
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brocknroller
Carpal Tunnel
Reged: 10/16/03
Posts: 1947
Loc: Vallée des nuages
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Quote:
Quote:
However, in an actual color extinction test at twilight, the SE outperformed the EII by about 8-10 minutes, perhaps because of the slightly larger aperture or more efficient light transmission.
In daylight, the EII looks "brighter" to my eyes.
Hail B'rock son of Gr'lka,
If you were testing the 8x SE and EII, in Cloudy Valley, I would be surpised that 2 mm. difference in aperture would make an 8-10 minute difference in twilight colour distinction. In Copenhagen, or another spot, at a high latitude, such a conclusion would make far more sense.
Happy observing,
Arthur
Sir Arthur of Manhattan Island,
Next week, I hope to take some photos of my backyard rain forest (which is almost entirely covered in foliage) and post them on the Cloudy Days Forum.
I recently bought a pith helmet to protect me from falling coconuts (British Royal Marines surplus).
The light levels are quite low on a cloudy day, but it's a pastoral setting rather than a cityscape so I will throw in a scaled down version of "Den Lille Havfrue" to make it look more like Copenhagen. :-)
After seeing the pix, it will become obvious why I purchased a CZJ 8x50 Octarem (though in hindsight it would have been much cheaper to attach a flashlight to my 8x32 SE since the images in both bins are fairly similar except for brightness).
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B'rock, son of Grilka
Member of the House of Kozak
Klingon Poet-Warrior
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"The character of a Klingon poet-warrior is measured not only by the metal of his blade--but also by the mettle of his words."
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BobinKy
Carpal Tunnel
Reged: 04/27/07
Posts: 1683
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Another point I want to throw upon the table is the observer's awareness of their own color sensitivity. In my mind, this is similar to the observer's awareness of their own interpupillary distance, eye pupil size (dark adapted and daytime), facial bone structure, or binocular weight and size they can comfortably hold in their hands.
The point on the table--now hear this--I think observers should develop an awareness of their personal sensitivity to colors. This probably will not come with the purchase of the first optical instrument. And this awareness may not come until they own several instruments and have done a considerable amount of optical observing.
The awareness of our unique color sensitivity, along with our personal field comparisons of several ED/nonED models, may influence whether we decide to add one or more ED binocular models to our selection of optical instruments.
I did this with two separate models--Swift Audubon 820 ED 8.5x44 porro and Pentax DCF ED 10x50 roof--and I decided to invest additional money and go for the ED versions. Now, two years later, I am glad that I did.
Others may see it differently.
. . .
A related issue to the observer's awareness of color sensitivity is the observer's color preference.
Myself, I find that I enjoy a Minox color rendering in the fall and winter seasons, and the Pentax color rendering in the spring and early summer. Of course, what I am seeing is really a type of chromatic aberration--albeit, in my eye, a very pleasant chromatic aberration.
Others report they prefer neutral color or no color bias in their binoculars. I must confess that most of the time I prefer neutral color when I view. This is one reason I frequently observe the night sky with Nikon SE binoculars. Of the binoculars in my selection, the SE is most neutral. Someday, I would like to compare the SE color rendering with the Leica color rendering, which is advertised as the most neutral glass around.
As for my selection of telescope eyepieces, I have decided to build a complete set of the Pentax XWs, which some observers report to be more neutral than the Televue assortment. With telescope observing, I am learning the eyepiece quality is an important component to the observing experience.
. . .
How about ED glass for night sky observing?
Much has been written in this thread about daytime observing with ED binoculars. I confess I have contributed to this more than most by posting links of similar discussions from the Bird Forum.
However, I find ED binoculars have their niche in night sky observing with 8x or 10x ED binoculars: Sweeping the Milky Way
Moon
Planets
Constellations (particularly those with bright color stars)
Double stars
Large open clusters
Meteor showers Sure, my 12x50, 16x70, or 22x85 will see more stars and DSOs than either my 8.5x44 or 10x50 EDs.
But when I desire to relax and enjoy the color of the night sky, I cover my Dob and large binoculars, head for the chaise lounge, and let the ED binos fill me up with color. I particularly like the way the orange and red stars pop in the Pentax DCF ED binocular. I also enjoy the color of the night sky with a 70mm ED refractor and a Pentax XW 40mm wide-field eyepiece (11x, 6.6 exit pupil, and 6.5° FOV).
But I have found that when I pass the ED optics to family and friends, they do not rave about the color as I do.
I wonder if they see what I see?
I am finding this to be a difficult question to discuss. I have tried to leave the optical engineering to others who know much more than I ever want to learn. Particularly our forum moderator EdZ, who is fantastic. And Brock, who never ceases to amaze me with bi-lingual postings.
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Bob
38°N
Edited by BobinKy (07/03/09 08:25 AM)
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Andresin150
sage
Reged: 08/14/07
Posts: 305
Loc: Bogotá - La Calera / Colombia
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what an interesting thread this is....... learning a lot here.. 
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25x150 MT
30-50x120's
Ultra 15x70's
GOTO NEX Planetarium
1 Macaw, 1 Toucan, 1 parrot and many other little ones...
And the nicest greenhouse!
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FrankKD
member
Reged: 09/10/08
Posts: 12
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Very interesting. Please keep the discussion going gentleman.
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EdZ
Professor EdZ
Reged: 02/15/02
Posts: 14732
Loc: Cumberland, R I , USA42N71.4W
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I was asked in another thread (Comparing 22x85, 22x70 and Tak22x60) if I intended to mask the objects of the larger binoculars to compare the slower resulting f# to the smaller and slower Tak. Let's look at that for a moment.
See this note from my original post in this thread
Quote:
Also, the amount of color error seen is dependant on focal ratio, an f/4 having greater potential color error than an f/5. Finally, aperture plays a significant role in color correction. An f/4 80mm will show one half the color error as an identically designed f/4 160mm lens.
If I were to mask down the objective of my f/4.7 22x85 to 60mm I would get an f/6.7 60mm, nearly identical to the Tak f/7 22x60. And I'm certain the color correction of the GO22x85 would improve. But I would not be able to isolate how much of the improvement is related to smaller aperture and how much is related to slower f ratio.
We know that given equal design quality and equal f ratio, a smaller objective produces less color. So the color of the 22x85 when masked to 60mm, as a result of smaller aperture should be reduced to 60/85, or to 70% of original.
We also know that slower f ratio in an equal sized equal quality scope would produce less color. The f/6.7 60mm masked objective would produce less color than the full open f/4.7 85mm objective.
The difficulty would be in attributing how much color correction is a result of which changed aspect.
These issues raised here are not specifically relative to ED binoculars. However, you can see from this example, it is quite difficult to assess how much color correction in a binocular is attributable to ED, how much to aperture and how much to f ratio. And although not needed in my example since all are 22x, there would be a difference attributable to power if it were different. If any of those are different in comparison binoculars the assessment becomes rather difficult. And as I stated earlier in this thread, few reviewers are taking the steps to isolate each cause when comparing binoculars.
edz
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Teach a kid something today. The feeling you'll get is one of life's greatest rewards.
member#21
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