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ZEISS DTI thermal imaging cameras. For more discoveries at night, and during the day.

Optical Performance 8x56 FL vs 8.5x42 SV (1 Viewer)

I just can't bring myself to use those winky things, all my teachers would roll over in their graves, and I hope I'm never THAT afraid somebody will get mad at me. Anyhow, old fashioned tongue in cheek, and an underlying assumption of mutual respect, will have to do. RonE and I know we are kidding each other.

"the unusually clean and transparent appearing center field of the Zeiss in daylight, which is unmatched by any other binocular in my experience" Ach!, a blight on such superstitious beliefs.

Thanks for the fun. Excuse me, I must go measure a force, or an angle, or something.
Ron
 
Wow! You go away for a day for some amateur geology (following the maps from The Roadside Geology of Pennsylvania), and you come back, only to find that you've had the honor (however dubious) of having a major Prize named after you (when do I get my FRAGELEE leg lamp?) and even more shocking, you find that Ronh, a self-professed empiricist (remember the lead vs. lead free glass thread when he declared his deepest "faith" in science?), having "his moment of doubt and pain" when his normally vertical thinking suddenly took a horizontal side step as he realized there were some things such as the aesthetics of "the view" through a binoculars that defy being quantified.

Even if it was a mooreorless tongue-in-cheek comment, I'm hoping that Ron had a gestalt moment, in which he realized that no matter how refined technology becomes, some experiences will always defy the quant's best efforts at measuring and numbering.

I don't mourn for that, I rejoice in it. Not just because I'm a "soft headed dreamer," but I would feel sad if someone like Surveyor, whose brilliance at once astounds me and mystifies me, would look at a rainbow and fail to appreciate it for its ephemeral beauty but instead, quickly take out his spectroscope and attempt to measure the wavelengths to evaluate the rainbow's hue, value, and saturation and miss the pure joy of the moment.

I remember one such moment - the Leonid Meteor Storm - where over 1,000 meteors per hour (more a the peak) rained down from the sky.

I was watching the event with sheer delight and awe, enjoying the "spectacle" of the event and enjoying the swirling colors of smoke left by the occasional "fireball". Meanwhile, some members of the astronomy club where sitting with red light and pen in hand, counting the number of meteors (which was nearly impossible anyway since the count was overwhelming, but none-the-less, they prodded away 2,436, 2,437, 2,438...).

When a particularly bright and beautiful fireball exploded in the sky above us, a couple of them stopped counting and let out a loud "WOW!" while others continued their count - 2,439...)

Some of what we see through binoculars is non-quantifiable and falls into the shadow realm of art and aesthetics.

I find it ironic that Robert Heinlein, a science fiction writer, who created speculative, imaginary worlds said: If it can't be expressed in figures, it is not science; it is opinion.

Try to quantify Heinlein's imagination.

I find this quote from my Uncle Albert, the Supreme Quant, more enlightening:

“Imagination is more important than knowledge. For knowledge is limited to all we now know and understand, while imagination embraces the entire world, and all there ever will be to know and understand."

I would add and "all we may never fully know or understand but which has no lesser value to us".

I get the feeling from "reading in between the lines" that some quants not only think that "what cannot be expressed in figures is opinion," but that those opinions (and observation) are of lesser value.

Look at the face of your new born baby and tell me that the feeling you have is of lesser value than a well figured light curve, and I'll eat my David Wells' Yankees cap!

Brocknroller, the soft headed dreamer (and damn proud of it!)
 
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Hello Brock;

I agree with most of what you say.

At this point I feel like a distinction of my beliefs may be in order.

Since we are on a forum that discusses both use and comparative recommendations I have two sets of criteria for all the optics I use, but will only discuss binoculars. I feel these are distinct and separate activities.

First, there is the use for their intended purpose, to look at nature or structures, whatever the task of the moment is. For that purpose I can enjoy them for just what they are. I use my Leica BA’s almost exclusively this time of the year just because of the postcard quality of the colors of the changing leaves, which I can’t explain..

Second, there is another mode of discussion on BF, that of comparing and recommending optics for others to rely on. For that purpose, I am far more critical and analytical and want to detail actual differences, not just my preferences.

Therefore, I feel that the two different objectives deserve different sets of priorities and approach each accordingly.

Sorry for dragging you into the fray, but your preference towards fast, smooth focusing was the first thing that came to mind.

Best.
 
To bring the discussion back to binocular optics I don't think there's a deep mystery as to why the 8x56 FL produces such a fine image in daylight. When it's stopped down to 20-30mm in bright light it has demonstrably lower aberrations in a star test than smaller high quality 8x binoculars do when they're stopped down to the same aperture.

At full aperture the 8x56 FL star tests rather poorly, certainly worse than 1 wave. To use a few examples of 8x binoculars that are often discussed here, the Nikon 8x32 SE, 8x30 EII and Zeiss 8x42 FL all star test better at their respective full apertures. But, if all of them are stopped down to 20mm and star tested at 24x (something I just did in my backyard) the 8x56 FL behaves like an excellent 20mm telescope with better than 1/4 wave optics and very little longitudinal CA. The others are worse to various degrees: the 8x42 Fl maybe 1/3-1/4 wave, the SE a bit worse (plus more CA) and the EII at the bottom at maybe 1/2 wave with obvious CA. All of the images look good at 8x since the magnification is so low, but the 8x56 image looks "cleaner and more transparent" than the others because its stopped down focal ratio is higher, so its aberrations are lower. Do we really need to invoke some inexplicable mystery for that?
 
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Hello Brock;

I agree with most of what you say.

At this point I feel like a distinction of my beliefs may be in order.

Since we are on a forum that discusses both use and comparative recommendations I have two sets of criteria for all the optics I use, but will only discuss binoculars. I feel these are distinct and separate activities.

First, there is the use for their intended purpose, to look at nature or structures, whatever the task of the moment is. For that purpose I can enjoy them for just what they are. I use my Leica BA’s almost exclusively this time of the year just because of the postcard quality of the colors of the changing leaves, which I can’t explain..

Second, there is another mode of discussion on BF, that of comparing and recommending optics for others to rely on. For that purpose, I am far more critical and analytical and want to detail actual differences, not just my preferences.

Therefore, I feel that the two different objectives deserve different sets of priorities and approach each accordingly.

Sorry for dragging you into the fray, but your preference towards fast, smooth focusing was the first thing that came to mind.

Best.

Ron,

It's reassuring to hear that you like to "stop and smell the roses" before you stick them under a microscope and dissect them (so to speak)!

Like that one - "postcard quality of the colors of the changing leaves". You can also wax poetic!

So do I, though it seems that at least one or two detractors would prefer if I gave "just the facts, mam".

However, I do that all week as a journalist so when I get on the forums, I like to be more creative and use humor, cultural references (which may not always translate across the country let alone across the pond), idioms, analogies, metaphors and similes instead of dry prose structured in a pyramid fashion (the butler did it and here are the facts in descending order of importance).

As far as focusers, yes I like mine smooth as a baby's bottom, but not fast as the 2006 Bugatti Veyron 16.4, which could do 0-60 in 2.5 seconds (the bin equivalent would be the 8x32 LX, which does close focus to infinity in just under 1/2 turn).

I like bin focusers that are medium fast (~1.5 revolutions cf to ∞).

Too fast and I overshoot my target and it also plays havoc with my focus accommodation.

I should also make a distinction of my beliefs by saying that I have no beef with the quantitative analysis of bin features. At times (at least when I can understand what the results are), I find your technical reports, Henry's, and even that schoolmarm Edz's helpful in making purchase decisions (or more likely these days, adding or deleting them to/from my "Wish List").

However, I probably do come off at times as anti-quant. Most of this stems from the Wall Street Meltdown, which I have been writing about for three years now. I even interviewed a "quant" who works for a local hedge fund for one article.

If you watched 60 Minutes tonight (if you had the patience to wait for the football game to finally end), you would have heard the latest scheme that the big investment banks involved in the "Meltdown" last spring and smaller hedge funds are hatching to beat the system.

In a nutshell, they are using supercomputers to get stock information faster than even Wall Street floor traders and remote trading companies by having their "quants" devise algorithms that can detect trends within milliseconds and buy and sell stocks automatically based on that instant analysis.

The FCC rep interviewed said that "speed trading" was in part responsible for the "mini market crash" last spring, and that they are now putting in place "circuit breakers" such that if a stock goes up 10 percent in a very short period of time, trading on that stock will stop.

As facts about "fast trading" has spread through the media, small time investors are feeling that the system is "rigged" and are becoming more reluctant to invest. Those investors are the ones who are providing money for companies to grow and hire new employees. The fast traders who work on "puts" and "calls" (betting on stocks going up or down w/in a certain period of time) aren't contributing anything of real value but rather are just making their firms richer.

In case you missed it, here's a recap:
http://www.cbsnews.com/stories/2010/10/07/60minutes/main6936075.shtml

So what's my beef? The quants are doing the same thing as they did before - making their quantitative analysis w/out regard to its "real life" consequences.

My belief is that science (or in this case, math) must always be conducted in a socially responsible manner.

Brock
 
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Henry,
Short of putting your Zeiss on the vivid-o-meter, that is a good science based explanation of part of its excellence. You say, of your 8x56,
"its aberrations are lower. Do we really need to invoke some inexplicable mystery for that?"

No, but like I said to RonE, you can't even tell if the binocular is coated, from this statement about its lack of aberrations.

So, another necessary ingredient of the argument, hardly mysterious and which you obviously just forgot to mention, is that the FL transmits around 93% over most of the visible. Add a rational explanation that the large exit pupil keeps most of the veiling glare away from the eye's entrance, and the argument would be sewn up, at least I'd be convinced as a sort of scientist, that it has to be a superb binocular.

In fact, I think the latter two things may be the most important elements in the mix. It is kind of hard to believe that the near-perfect wave accuracy of the the 56mm operating at 20mm is perceptibly better than 1/4 to 1/3 in the 42mm, given that the 42mm will undoubtedly do better too at reduced effective daytime aperture, and given the low magnifications which fall far short of exposing these small defects. It is also hard to believe that the two binos, being of the same series, will have appreciably different light transmissions. And, it's also kind of hard to believe the difference in veiling glare is appreciable except in harsh lighting conditions.

So, I don't think you have quite proved that the 56mm must give a better image than the 42mm. No offense, I believe it does, but ONLY because you say it does, and because I trust you!
Ron
 
Ron,

Hey, thanks for the blind trust, but I think you deserve verification. What I hoped to do was show why the 8x56 FL (and probably other high quality 8x56's) produce such a good image in daylight compared to smaller 8x binoculars even when the smaller binoculars are actually better optically at full aperture or at least star test better at full aperture.

All the binoculars I tested yesterday have light transmission above 90% and there were no problems with veiling glare in the test set up. I can't see that the 8x56 FL has any superior optical quality compared to the 8x42 FL except for lower aberrations when they're both stopped down to the same aperture in daylight. I think the difference between about 1/5 wave and about 1/3 wave is visible in this case because 8x, while low magnification in absolute terms, is not so low for a 20mm aperture.

Henry

Edit: If you have the Suiter book look at the MTF diagram of spherical aberration on page 176. The relevant part of the curves for my eyes in an 8x20 telescope would be spacial frequencies below around 0.5 where my eyesight acuity would cut off the resolving power. 1/3 wave optics show an MTF drop to about 0.25 at 0.5 spacial frequency, 1/5 wave optics drop to about 0.35 at the same frequency. That, very unrhapsodically, is what I think I see as "cleaner and more transparent".
 
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Henry,
I don't have Suiter, but you have described the MTF well enough to understand. That is a good explanation, and thanks. (I have a hunch the 8x56 FL has edged out the 8x42 SV!)
Ron
 
Ron,

I briefly star tested an SV, but I was looking mainly for defects so I don't remember the correction for spherical aberration. 42mm binoculars could easily be made with aberrations as low as the 8x56 in stopped down mode. They just need longer focal lengths. 170-180mm should do it. But that would then require longer heavier binoculars with bigger prisms so there are powerful marketing reasons for not doing it.

Henry
 
Here's another proponent of "bigger is better". Wayne Mones, one of the former? reviewers of BVD is now reviewing bins for Audubon Magazine. The way he always sticks in a reference about eating food while birding, I expected him to be as big as Stephen Ingraham, but he's slim. He looks a bit like Harrison Ford.

Here's an excerpt from his review of the Swaro 8x56 SLC:

"So why bother schlepping these monsters around? Because it isn’t only about brightness. It’s about the quality of the image, and Swarovski’s 8x56 SLC offers perhaps the best image that I have seen in any binocular."

Full review:
http://magblog.audubon.org/size-matters-case-really-big-binoculars
 
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Here's another proponent of "bigger is better". Wayne Mones, one of the former? reviewers of BVD is now reviewing bins for Audubon Magazine. The way he always sticks in a reference about eating food while birding, I expected him to be as big as Stephen Ingraham, but he's slim. He looks a bit like Harrison Ford.

Here's an excerpt from his review of the Swaro 8x56 SLC:

"So why bother schlepping these monsters around? Because it isn’t only about brightness. It’s about the quality of the image, and Swarovski’s 8x56 SLC offers perhaps the best image that I have seen in any binocular."

Full review:
http://magblog.audubon.org/size-matters-case-really-big-binoculars
http://magblog.audubon.org/swarovski-introduces-new-model-replace-els
"The image is the best I have seen."
 
Note the dates of the reviews, the 8x56s were reviewed in may of 2010, two months after the new ELs.
Wayne has been enjoying the better views he desires.
 
Big deal!

Quit complaining about their weight!

Last year I was on the deck at Cape May Point and a couple of older grandmotherly type ladies near me were using just as big or even bigger Swarovskis! One might have been a 15x. She had left an objective cover on one barrel and was using hers like a handheld telescope. They seemed to know their birds too!

Bob
 
Big deal!

Quit complaining about their weight!

Last year I was on the deck at Cape May Point and a couple of older grandmotherly type ladies near me were using just as big or even bigger Swarovskis! One might have been a 15x. She had left an objective cover on one barrel and was using hers like a handheld telescope. They seemed to know their birds too!

Bob
So, are you putting your order in?
 
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