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Ultravid 7x/8x 42 pre-HD, HD, HDplus transmission figures (2 Viewers)

Tom,

It was my own comparison, conducted over the space of a couple hours at the Cape May Bird Observatory's optical shop. The shop faces Lake Lily, a 13-acre freshwater pond surrounded by varied vegetation; I would take two binos at a time and step outside and scan the far shore, looking for resolution in the foliage and detail in the shadows.

John

Thank you, John. Sounds like a good practical test.

Tom
 
When I first viewed through an FL 8X32, I noticed a slight blue hue...This was after I was viewing with a glass that had an overly red/brown bias for a while. It is amazing how the human eye adapts, I do not notice it anymore.

Andy W.
 
I have been reading this thread with interest. The question asked by the original poster, was the
transmission levels of the various Ultravids.

I am not able to view Gijs reports, so maybe someone can post those results, in a simple form for
some of us wondering. Include the 10x42 if able.

Thanks, Jerry
 
Ultravid transmission graphs by Gijs

Hi Jerry

Here are the ones that I have been able to find. No 10x though.

Measured transmissions are the average of a number of measured spectra, error margin is +/- 0,5%.

Many thanks to Gijs van Ginkel for making his test results available and to Jan van Daalen of House of Outdoor, for hosting the test results and reviews on his website: http://www.houseofoutdoor.com/verrekijkers/verrekijkers-testen-en-vergelijken/

Lee
 

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Lee:

Thanks for the chart, I find it very useful. Look at the transmission of the 7x42 Habicht on the 2nd
chart. That binocular is special, very bright and quite a view. The color is very even, one of the
best it seems.

Jerry
 
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CJ,

One of the intriguing aspects of my browsing on colour perception is the role of a common amino acid substitution in the L-opsin pigment of the long wavelength (red) receptor. The gene for it is carried on the x-chromosome. The two variants have slightly different absorbance profiles and therefore sensitivities. It means women have two copies and men only one. There is some conflicting data on what this means for colour perception, but at least some experimental designs show that women who have both gene variants have better colour discrimination in certain parts of the spectrum. ;)

David
David,

That's interesting - thanks for that. All the other members of the exec were male, and I was the youngest by far. In those days I didn't know as much about colour reception other than the age related Monet style red shift, and the technicalities of chromacity, and white balance (I certainly didn't know of the different colour perception in each of my eyes, or even if it was in evidence then - I only discovered it scrutinizing binoculars about half a dozen years ago). I always put our differences of opinion down to age related factors. There are a few folk I know in my parents age group who are now post cataract surgery - they say the new vibrancy of colour in their worlds is a mini revelation.

David, others: Human spectral sensitivity, as I gather, is maximum about green, ranging from being max. at green-yellow in daylight to max. at blue-green at night. Until a couple years ago much was said in this forum about "brightess washout" in the Zeiss FL 7x42, vs the Leica Uv. 7x42, and by itself. Can a green emphasis in its transmission cause that, or conversely, can that arise from whatever other reason and cause a green cast? Thanks! If the question is not structured logically or is trivial please ignore.
It might help to look at these references for:-
short, medium, and long cone types (used in normal daytime photonic vision colour discrimination - compare that to Gijs measured transmission graph)
https://en.m.wikipedia.org/wiki/Color_vision
and also the transmission standard, https://en.m.wikipedia.org/wiki/Luminosity_function

I don't think you can get a binocular that is 'too' bright. Of course with your naked eye you wouldn't go looking at bright sunlight reflections off water, snow, or shiny metal objects either.
'Washout' etc is more related to flare and glare.



Chosun :gh:
 
I don't think you can get a binocular that is 'too' bright.
'Washout' etc is more related to flare and glare.

Chosun :gh:

That seems to be a valid point,
high transmission would rather decrease the risk of flare (and perhaps to some extent glare) by minimizing the amount of reflected light from every surface of the lens elements in the binocular.
 
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That seems to be a valid point,
high transmission would rather decrease the risk of flare (and perhaps to some extent glare) by minimizing the amount of reflected light from every surface of the lens elements in the binocular.

The idea about a bino that is so bright it washes all the colours out seems to me to stem from an imagined connection with what over-exposed photographs look like. This notion ignores that most binos pass only 90% of light (plus or minus a few percent) which means looking through binos is like looking through very weak sunglasses as around 10% of the light doesn't reach the eyes.

Lee
 
Maybe I need to go back, e.g. to Wikipedia as detailed by Chosun, and digest/review a bit on some subjects!

But the "brightness washout" I cite as written about on here was not due to glare or flare. I may be using the wrong words in quoting that, sorry: Googling now for "birdforum brightness washout", to check, did not get me too far.

There is such a thing as a binocular being too bright in a given situation. E.g., looking within the foliage of a tree near its edge with an 8x20 and an 8x42 of comparable optical quality the smaller binocular may give a clearer image of the subject because the sky behind is too bright for the user's eyes with the larger model. (I have experienced this.) Whether it can be described as "washout" (in whatever degree) I do not know.
 
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Maybe I need to go back, e.g. to Wikipedia as detailed by Chosun, and digest/review a bit on some subjects!

But the "brightness washout" I cite as written about on here was not due to glare or flare. I may be using the wrong words in quoting that, sorry: Googling now for "birdforum brightness washout", to check, did not get me too far.

There is such a thing as a binocular being too bright in a given situation. E.g., looking within the foliage of a tree near its edge with an 8x20 and an 8x42 of comparable optical quality the smaller binocular may give a clearer image of the subject because the sky behind is too bright for the user's eyes with the larger model. (I have experienced this.) Whether it can be described as "washout" (in whatever degree) I do not know.

That seems odd because your pupils will close down to their minimum in light as bright as this no matter which bino you are looking through.

Lee
 
It does not happen with a bright image. It happens when there is contrast as described.

I expressed myself badly adhoc, apologies for not being clear. I was referring to the way you blamed the problem on the brightness of the sky affecting your eyes:
Quote: "the sky behind is too bright for the user's eyes with the larger model".

Lee
 
Lee, apology not needed! Maybe I did not describe the "given situation" thoroughly enough. You are looking through the binocular at or within the fairly dense foliage of a tree, say at a bird/s. Your pupils have had enough time to dilate a bit. You now look at or into the foliage near its boundary with the brightness beyond... BTW, "blaming the sky" sounds like something out of an ancient Chinese poem or proverb, so thanks!
 
Lee, apology not needed! Maybe I did not describe the "given situation" thoroughly enough. You are looking through the binocular at or within the fairly dense foliage of a tree, say at a bird/s. Your pupils have had enough time to dilate a bit. You now look at or into the foliage near its boundary with the brightness beyond... BTW, "blaming the sky" sounds like something out of an ancient Chinese poem or proverb, so thanks!

OK I get it now but it still sounds odd because I am sure that other more knowledgable members have posted that your pupil closes down almost instantaneously given a burst of light.
And you are right about 'blaming the sky', it does indeed sound like a sage oriental saying :king:

Lee
 
My HT is purported to have 95% transmission and I can directly compare it to something with a much smaller aperture and lower transmission - Terra 8x25 and Conquest HD 8X32 - and the HT beats both clearly for retaining better contrast and detail in heavily back-lite situations, so that theory is a non-starter for me.

This whole brightness wash-out thing is something I have never seen in a quality binocular before, as higher transmission suggests less lost light through reflection.
 
I describe what I have experienced. It was not in a more usual situation of backlighting but as described. I am afraid I do not remember the models of binocular. The smaller would actually have been an 8x25 though as I have not viewed through an 8x20 for a long time, and I used 8x20 in that example because the difference should be still more. Presently I have only 25 mms so cannot try this right now, but will again when I have access to a 42 and an opportunity.
 
I am more inclined to think that shifting cloud thicknesses in the far distances and randomly moving tree leaves closer-by led to a burst of brighter light just as the bigger binos were used giving the false impression that this was something to do with the binos.

Lee
 
Pl. see this post by Henry Link 2 days ago in another thread.
Also by Binastro a few posts below that.
If your pupil is at 5 mm
the effective aperture of an
8x20 is 20 mm, of an
8x42 is 40 mm.
If your pupil is at 4 mm then of an
8x20 is 20 mm, of an
8x42 is 32 mm.
A bright sky is (effectively) a light source, rather than a lit surface.
I reported my experience, and others can easily try that.
The theory applicable is not simple.
I did not need, nor wish, to get into it!
 
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Ad hoc I was certainly not questioning your experience but trying to make sense of it. We are visiting a nature reserve with some mature woodland this weekend and I will have several binos with me and I will give this a try.

Lee
 
Thanks Lee that of course is the best thing.
Almost certain the binoculars I used were 8x25 and 8x42.
32 vs 42 might possibly not be different enough.
 
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