SV's didn't really blow the little BN's away! (3 Viewers)

NDhunter said:

Dennis:

The case for the 10x40 Zeiss Classic, is a simple leather case, with no padding,
but longer than what you have been thinking of for the shorter 8x32. If you
are trying to find one of these, you will find it hard to get.

I have been watching your post, and a Zeiss FL case for the larger 8x42, is
nicely padded offers some extra room, and may be a nice case for your needs.
Do you remember the one you had for your FL 8x32?

Otherwise, how about putting that Leica into that nice Swaro. case that you
have for the SV. I do wonder about what you really need the case for, as for
many users, you just carry your optics, and have the optics covered, so don't
need much of a case.

Jerry

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I carry my binoculars over my shoulder IN the case until I am ready to use them and then I remove it from the case and put it around my neck so the case is still on my shoulder and then when I am done birding I like to put the binoculars back into the case. I guess I am kind of anal retentive. I like a case that holds the strap of the binocular and has it's OWN strap so I can put it over my shoulder or even preferable I like to strap it to my belt. I did like the case that came with the Zeiss FL. To me it represents the perfect case with it's belt loop it was convenient to carry the smaller 8x32 FL in it. I think the SV case is a little too big and bulky for my liking and I have my SV in one of those Tamrac green cases that were selling on Ebay UK awhile back that are rounded on the top and they have a zipper along the top. The SV fits perfect in it with the strap stuffed in on the side and the strap actually holds the SV's more secure. The Tamrac case is much lighter. I also have a Vero Vellini neoprene strap on the SV because it is lighter than the strap that came with the SV and you can't shorten the strap that comes with the SV. I ordered the Eagle Optics 8x42 case so I will try it and see how it works. It should be big enough to hold the Leica 8x32 BN's with the neoprene strap. I will let you know how it works. It is similar to the Zeiss case and probably cheaper to buy.

[email protected] said:

I think your on to something with your theory about the silver prism coatings. I had the Zen Ray 8x43 ED with silver prisms and then later when they improved them with Dielectric prisms I had the newer model EDII and I remember thinking that even though they were slightly brighter there was something I didn't like as well about them. They seemed colder and almost nervous like the objective was trying to grab ever photon of light that was available. It could be I like the spectrum of colors presented by the silver prisms. Interesting theory and deserves more thought.

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I'm sure it has nothing to to with the silver coatings of the prisms because at least the dielectric ones of Leica are superior both, in transmission and in color fidelity as well. When comparing binoculars of different generations in development like for instance the Trinovid vs. Ultravid one should always bear something in mind that is regularly mentioned in Birdforum by many experienced users and that is sample variation. All the new technologies in coatings and glasses (e.g. ED-glass) doesn't have any effect to the resolution of the optics. In former times when more steps of production were hand-made ones it was easier to controll the quality of the optics for experienced workers and opticians. So there were a lot of binoculars and scopes with very good resolution power which is the direct result of low aberrations. The resolution power of people with a very good visus is much better than the often quoted 60 arcseconds would suggest. These 60" is believed to be determined by of the numbers of cones in the fovea. But the visual system is capable to increase the resolution power with its own methods of perception. By all means, the eyes are always thankful if optics represent sharp images of high resolution. I gave some further informations about that some years ago, here in Birdforum. So, to cut a long story short, I assume that your particular sample of the Trinovid is a very good one of high resolution.

With the introduction of the Trinovids Leica had a head start for years in respect of glare controll. It was always a surprise for me how many reviewers did overlook this. Finally, after many years some other manufactorers did suss it but I'm not quite sure if they really disclose the secret.

Steve

Hinnark,

I have no doubt that what you are saying is accurate. I think that what Dennis is saying, and what I mentioned earlier, is also true to an extent. Silver prism coating tends to reflect certain wavelengths of length more so than the dielectric. As a result the images tend to appear "warmer" for lack of a better word. That warmer image representation tends to be more "relaxing" and comfortable to my eyes at times. I had the same experience with the two binocular versions that Dennis just referenced. I also found the Zeiss Conquest 8x30 (not sure of the prism coating) and the Trinovid BN series to give me that same relaxed feeling to the image. Even the original Meopta Meostar gave me much the same impression.

Now, having said that I would say that I do also get a somewhat similar impression when comparing the Zen Ray ED2 with the ED3. They both use dielectric mirror coating though of a different composition. However, the antireflective coatings on the lenses has also changed. It could then be that it is a specific combination of mirror and lens coatings that promotes that relaxed feeling. I feel the ED2 has the more "relaxed" image though the ED3 appears noticeably brighter.

Just some things to consider.

I think what people find "relaxing" and "warm" is light transmission with an elevated shelf from maybe 580 nm to 680 nm, probably combined with a roll-off in the blue. Essentially a mild yellow/orange/red color filter that gives everything a nice "golden hour" look. The image should look even more relaxed if the light transmission is not too high, say in the 80%-85% range of the Trinovids. I prefer colors unchanged by the binocular and I like all the light transmission I can get. If the image is so bright that it hurts when the conditions are so bright that it's supposed to hurt I'll put on some sunglasses.

Hi Henry,

Do you have transmission data to compare the FL vs BGATP models that use A-K prisms?

Do you think that observed differences would be due, primarily, to multicoating efficiencies? I realize that the FL uses a focusing lens, making for more surfaces and possibly more glass absorption.

Change of subject. My impression from cut-away diagrams is that Swaro uses a positive focusing lens on the SLCs. Would that make sense? I'm still perplexed by internal focusing systems in general.

Thanks,
Ed

[email protected] said:

Maybe I will give the leather case another go. My problem with it is sliding the binocular straps through the opening in it. They seem kind of hard to fit through there and don't slide that easily Of course my strap is doubled now because I back looped it through the buckle the way people on the forum suggested to keep the strap from falling off. You slide the case up when you use your binoculars right and the case stays on the strap and then you recover your binoculars with it correct? I am just not used to using my binoculars that way. I didn't even figure a big strap will fit inside of it as small as it is. Maybe I will try it.

Click to expand...

Based on what you wrote in your later posts about keeping the case with you while birding, I can understand why you wouldn't like the BN case. Your use of bino cases is quite different from mine, and I wouldn't be able to tolerate the BN case used permanently on the strap (I can hardly, and only sometimes, tolerate an ocular rainguard on a bin's strap). Since the BN case zips shut with a single zipper, it wouldn't seem a very good one for your uses, but the Ultravid case would be fine. It even has attachment buckles for its own strap (which is not supplied). The Zeiss 8x32 case would work too, but unless they've changed it, it is very bulky (big enough for a Leica 8x42 Ultravid).

--AP

Hi Ed,

Here's what I can find in my files.

Zeiss 8x56 Dialyt (ClassiC):

92.5% day, 90.6% night (3 samples tested by Leica, 2000)
93.1% day, 91.3% night (same samples tested by Swarovski)
94.4% day, 92.4% night (German magazine test 2005)
94.3% day, 93.1% night (German magazine test 2006)

A Zeiss 8x42 FL in the German magazine test 2005 measured 93.3% day, 90.5% night. BTW, a Leica 10x42 Trinovid in that same test measured 82.4% day, 81.2% night.

In the German magazine test 2006 a Zeiss 8x56 FL measured 94.5% day, 94% night.

The 2005 test results make sense to me if the coatings are similar. The 8x56 ClassiC has only 10 coated surfaces vs 16 in the 8x42 FL. I can't account for why the 2006 test measured higher transmission for the 8x56 FL, which also has 16 coated surfaces. I don't have any details as to what "day" and "night" mean in these tests and I don't know how Leica and Swarovski arrived at their numbers after measuring three samples.

Yes, both the SLC's and the old EL's used positive focusers, so they move backwards toward infinity focus.

Alexis Powell said:

Based on what you wrote in your later posts about keeping the case with you while birding, I can understand why you wouldn't like the BN case. Your use of bino cases is quite different from mine, and I wouldn't be able to tolerate the BN case used permanently on the strap (I can hardly, and only sometimes, tolerate an ocular rainguard on a bin's strap). Since the BN case zips shut with a single zipper, it wouldn't seem a very good one for your uses, but the Ultravid case would be fine. It even has attachment buckles for its own strap (which is not supplied). The Zeiss 8x32 case would work too, but unless they've changed it, it is very bulky (big enough for a Leica 8x42 Ultravid).

--AP

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I got the 8x42mm case from Eagle Optics and it quite nice. I think I like it a little better than the Vortex case. The material seems a little nicer. It has a belt loop and a detachable strap so all your bases are covered. The Leica 8x32 BN fits in the case nicely with enough room off to the side for the strap but on the other hand it isn't too big and bulky or heavy. It seems like it should be pretty waterproof also because it seems to be made of an impermeable waterproof material. It also uses a snap buckle to close it so it is easier to open than a zipper.

henry link said:

Hi Ed,

Here's what I can find in my files.

Zeiss 8x56 Dialyt (ClassiC):

92.5% day, 90.6% night (3 samples tested by Leica, 2000)
93.1% day, 91.3% night (same samples tested by Swarovski)
94.4% day, 92.4% night (German magazine test 2005)
94.3% day, 93.1% night (German magazine test 2006)

A Zeiss 8x42 FL in the German magazine test 2005 measured 93.3% day, 90.5% night. BTW, a Leica 10x42 Trinovid in that same test measured 82.4% day, 81.2% night.

In the German magazine test 2006 a Zeiss 8x56 FL measured 94.5% day, 94% night.

The 2005 test results make sense to me if the coatings are similar. The 8x56 ClassiC has only 10 coated surfaces vs 16 in the 8x42 FL. I can't account for why the 2006 test measured higher transmission for the 8x56 FL, which also has 16 coated surfaces. I don't have any details as to what "day" and "night" mean in these tests and I don't know how Leica and Swarovski arrived at their numbers after measuring three samples.

Yes, both the SLC's and the old EL's used positive focusers, so they move backwards toward infinity focus.

Click to expand...

Many thanks, Henry. :t:

I'm going to digest these data for a while, and also research what "day" and "night" values mean.

Ed

elkcub said:

Many thanks, Henry. :t:

I'm going to digest these data for a while, and also research what "day" and "night" values mean.

Ed

Click to expand...

That day and night value is weird isn't it. If you find out what it means let us know. You would think transmittance would be the same at day or night.

Transmittance through a binocular is the same, day or night. The two figures are based on the shift in eyesight sensitivity from a peak in daylight around 555 nm to a peak in darkness around 510 nm. I've been informed that Zeiss' "day" and "night" figures are just single wavelength values for 500 and 550 nm. I suspect most others are similar with perhaps slightly different wavelengths chosen. I think Ed is hoping to find a method that considers more eyesight parameters than just photopic and scotopic peaks.

henry link said:

Transmittance through a binocular is the same, day or night. The two figures are based on the shift in eyesight sensitivity from a peak in daylight around 555 nm to a peak in darkness around 510 nm. I've been informed that Zeiss' "day" and "night" figures are just single wavelength values for 500 and 550 nm. I suspect most others are similar with perhaps slightly different wavelengths chosen. I think Ed is hoping to find a method that considers more eyesight parameters than just photopic and scotopic peaks.

Click to expand...

You would think just photopic and scotopic peaks would be oversimplified. I will be curious to see what other parameters play a part in night and day vision sensitivity.

henry link said:

Transmittance through a binocular is the same, day or night. The two figures are based on the shift in eyesight sensitivity from a peak in daylight around 555 nm to a peak in darkness around 510 nm. I've been informed that Zeiss' "day" and "night" figures are just single wavelength values for 500 and 550 nm. I suspect most others are similar with perhaps slightly different wavelengths chosen. I think Ed is hoping to find a method that considers more eyesight parameters than just photopic and scotopic peaks.

Click to expand...

Right. The issue is what do the day and night figures mean, and how are they calculated. Obviously, they refer in some way to photopic and scotopic sensitivities of the eye. The simplest computation would be just to use the two peak values at, let's say, 555nm and 507nm. http://hyperphysics.phy-astr.gsu.edu/hbase/vision/bright.html At least with the evidence I have at hand, that doesn't seem to be what's done.

I've attached left and right data for the Leica 7x42 (probably BR). The second page of each shows the transmittance values every 5 nm. None of the peak values correspond, and interpolation or rounding errors would not be the reason. (Try 550 and 510, — same result.)

Assuming everyone uses the C.I.E. Standard Observer Relative Sensitivity Curves (see web site above and http://www.ies.org/PDF/PositionStatements/PS-02-10.pdf), my reasoning is to use it as a weighting function to compute the day-value:

1. Multiply the energies in the input spectrum by the photopic sensitivity function over the visible range. Mathematically, this would be the "dot-product" and simply means to cross multiply the elements in the two vectors and then add them all together. The result is a single number. This represents the total visible energy (TVE), measured in lumens, the eye would see if the input spectrum were presented directly to it.

2. Now take the output transmission expressed as spectral energies emerging from the instrument (i.e., not as percentages as shown in the charts) and again calculate the dot-product with the photopic sensitivity function. This single number represents the reduced visible energy (RVE), in lumens, the eye would see if the input were first filtered by the instrument.

3. Finally, to express this as a "day-value" percentage compute: DV = RVE/TVE and multiply by 100.

The same procedure would be used to calculate the night-value using the scotopic sensitivity function instead.

I would be very surprised if something very close to this were not done. Otherwise the only datum used would be the peak value of each sensitivity function, which would be much less meaningful and almost trivial.

Naturally, more calculating on my part could validate this, but I'm not a glutton for punishment. I'll leave work for someone else. :king:

More discussion of this would always be welcome.

Ed
P. S. 'Oversimplified' is a good word, Dennis, for the reasons you said. For one thing all binoculars with the same transmittance at the peak values would have identical day/night values.

elkcub said:

Right. The issue is what do the day and night figures mean, and how are they calculated. Obviously, they refer in some way to photopic and scotopic sensitivities of the eye. The simplest computation would be just to use the two peak values at, let's say, 555nm and 507nm. http://hyperphysics.phy-astr.gsu.edu/hbase/vision/bright.html At least with the evidence I have at hand, that doesn't seem to be what's done.

I've attached left and right data for the Leica 7x42 (probably BR). The second page of each shows the transmittance values every 5 nm. None of the peak values correspond, and interpolation or rounding errors would not be the reason. (Try 550 and 510, — same result.)

Assuming everyone uses the C.I.E. Standard Observer Relative Sensitivity Curves (see web site above), my reasoning is as follows to compute the day-value:

1. Multiply the energies in the input spectrum by the photopic sensitivity function over the visible range. Mathematically, this would be the "dot-product" and simply means to cross multiply the elements in the two vectors and then add them all together. The result is a single number. This represents the total visible energy (TVE) the eye would see if the input spectrum were presented directly to it.

2. Now take the output transmission expressed as spectral energies emerging from the instrument (i.e., not as percentages as shown in the charts) and again calculate the dot-product with the photopic sensitivity function. This single number represents the reduced visible energy (RVE) the eye would see if the ambient conditions were first filtered by the instrument.

3. Finally, to express this as a day-value compute: DV = RVE/TVE.

The same procedure would be used to calculate the night-vision value using the scotopic sensitivity function instead.

I would be very surprised if something like to this were not done. Otherwise the only datum used would be the peak values of the sensitivity functions, which would be much less meaningful and almost trivial.

Naturally, more calculating on my part could validate this, but I'm not a glutton for punishment. I'll leave work for someone else. :king:

More discussion of this would always be welcome.

Ed
P. S. Oversimplified is a good word, Dennis, for the reasons you said. For one thing all binoculars with the same transmittance at the peak values would have identical day/night values.

Click to expand...

Ed:

Here is how the Europa, Ginkel binocular tests discuss the night and
day, transmission. I like how it is explained.

The full Europa 42mm. binocular test is good reading, now added the full Europa
Binocular 42mm tests. Page 3, discusses brightness and how our eyes view
things both night and day.

Jerry

Ed;

I am not sure I opened the whole document, seems abreviated. I saved it to a .pdf for you, at least what I could open.

Ron:

Thanks, for showing the part about the night and day. I now have attached the full review,
up above.

Jerry

Hi Ron,

Many thanks. (I got a bit confused there)

My last post was #73, and of course I'd like your comments.

Ed

NDhunter said:

Ron:

Thanks, for showing the part about the night and day. I now have attached the full review,
up above.

Jerry

Click to expand...

Brightness.
The brightness is determined by the exit pupil and the amount of light that passes through the lenses and
prisms, otherwise known as 'transmission'. For binoculars with the same exit pupil measurement and
differing light transmission, the latter determines the actual brightness. Measuring spectral transmission
curves requires equipment specifically designed for this purpose. The table contains the transmission values
measured. The transmission spectra in the colour range perceived by the human eye are also printed. The eye
contains two pigment systems for detecting light. In daylight, the eye uses colour-sensitive cones with
optimal sensitivity to green (550-560 nm); in low light, it uses rods with optimal sensitivity to blue (500-505
nm).

Click to expand...

Jerry,

What they say is true as far as it goes, but it is misleading. "Brightness' is a psychological response to retinal stimulation and is determined by the spectral energy emerging from the exit pupil of the binocular as modified (i.e., weighted) by the visual sensitivity function(s) of the eye.

The day and night values appear to address daylight vs nighttime viewing brightnesses. The numbers are expressed as a percentage of brightness without instrument obstruction. Allowing for measurement error, and a few other things, therefore, the numbers should allow us to appreciate the relative overall (perceived) brightness of any two binoculars.

Ed

Ed:

If you read through the Ginkel Europa tests, the chart of transmission for day and nite organizes these nicely for a wide range of binoculars.

One that stands out is the Bushnell 8x43 Elite, which has a night trans. of 83, Day 88, the comment they make on this one it has a Pink-red cast.

Most others have a more neutral trans. curve, as shown on the bar graphs.

Jerry

elkcub said:

Right. The issue is what do the day and night figures mean, and how are they calculated. Obviously, they refer in some way to photopic and scotopic sensitivities of the eye. The simplest computation would be just to use the two peak values at, let's say, 555nm and 507nm. http://hyperphysics.phy-astr.gsu.edu/hbase/vision/bright.html At least with the evidence I have at hand, that doesn't seem to be what's done.

Assuming everyone uses the C.I.E. Standard Observer Relative Sensitivity Curves (

Click to expand...

Hi Ed,

you are right about this. According ISO 14490-5 - Test methods for transmittance - as the relative spectral luminosity factor for photopic (day) vision is used as specified in Table 2 of CIE Publ. 18.2:1983. For scotopic (night) vision it’s the same source, Table 3. The measurements and calculations should be done in steps of 5nm over the whole visible spectrum (370-780nm).

Steve