Meopta 8x32 First impressions (1 Viewer)

It may not be entirely true that surface brightness cannot be increased as someone lying at the bottom of a swimming pool reported M31 brighter at an angle to the vertical because it was compressed on the long axis of M31, compared to its visibility out of the pool.

It may be that afocal adapters may do the same trick?

Gijs van Ginkel said:

Holger (post 53),
I can not help a non-believer, but I trust our measurements, since we know very well what we are doing, we are aware of potential pittfalls and we checked the measurements over and over. In addition we had our spectrometer calibrated by measuring standard instruments which were also measured by a German calibration institute and we had within experimental error exactly the same results. The only deviations which we could have are in the wavelenght range 450-460 nm, but that has to do with the relatively low output of blue light of our source of white light: a stabilised tungsten light source. That problem can be tackeled by collecting enough counts in the channels of the photon counter designated to these wavelengths since the uncertainty is connected to the square root of he total amount of counts collected in these channels. Over and we found the same results as Swarovski with their spectrometer (see their data sheet in which a transmission of 96% is reported for the Habicht 8x30).
We have also compared or data from different binoculars with data obtained by Zeiss with their spectrometer and we had the same results.
Zeiss found a (green) light transmission for the HT's of 95,3%, we measured 95,1-95,2%, which is within experimental error the same.
So I am not trying to convert you from a non-believer to a believer, but scientific pride does not permit us to make stupid mistakes and we are fully independent from whatever company, what does sometimes not make us popular.
Gijs

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Hello Gijs,

Don't get me wrong - you are doing a great job and I am convinced that you do everything possible to get these measurements as accurate as possible.

My experience during many years as a scientist has made me cautious, however. I learned that doing experiments is not so much about getting right (or wrong) numbers, but rather about understanding what is going on, how numbers arise, and what they can tell us. Currently, we are trying to understand the meaning of transmission, and this is not a trivial one.

Just as an example (though not directly related to your measurements) we may have a look at the attached picture - it shows the spectral composition of daylight. But there are two curves - one taken on a sunny day, the other one on a cloudy day. Now we want to know how much of that light is perceived through a binocular - so we fold these curves with the spectral transmission (measured with your spectrometer), then we fold the resulting curve once again, with the human eye's sensitivity curve and eventually obtain a number (the perceived "brightness" of the image). However, this number differs, depending on the spectral composition of daylight. A Zeiss HT, when compared with a Leica Ultravid, may appear particularly bright on a cloudy day (it transmits short wavelengths very well) but less impressive on a sunny day (when the daylight is warmer). I just want to say: Transmission itself and understanding what it means in practical application is something delicate, the number alone does not necessarily relate to the performance, when we forget to consider where the number comes from and how much it can tell (or, what exactly it cannot tell).

Apart from that, if your transmission result of the Habicht agrees well with the official one and 96% is in fact an established number, then I am happy to note it as the (current) new high score on transmission and cite it in my book. Thanks a lot for clarification!

Cheers,
Holger

Holger,

Finally. Thank you for bringing in the human luminosity function. Until now I'd completely given up using it in BF discussions.

Ed

FrankD said:

Gijs,

I certainly would agree that dielectric coatings on the Meostar is needed to make them competitive on all levels with the more expensive competition. My curiosity is piqued as to why Meopta has not upgraded this feature especially after choosing to upgrade to ED glass in the objective design. Dielectric coatings trickled down into lower price ranges before ED glass did at least in my experience.

There must be an explanation for this with the Meopta. Thoughts? Anyone?

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All MeoStar B1 series binoculars (including the 10x42 HD) have MeoBright 5501 ion assisted multi-coatings on all air to glass surfaces as well as phase correct Schmidt–Pechan roof prisms. These prism are silver coated.
Meopta does not not offer any binoculars with dielectric coatings

Holger,
Thank you for your comments that makes things more clear. I agree that we have to take into account the spectral sensitivity of our eyes in understanding how images are perceived given a certain color pattern, which a tranmission spectrum offers. That is one thing, but our visual system seems also capable of balancing our perception of color, so the colors perceived on a cloudy day are by our visual system perceived not different from the visual observation of colors on a sunny day despite the spectral difference between these two light regimes. So that puzzles me and if you have some explanation how that would apply to measured transmission spectra, than I would be happy. I did not observe great color differences with the Victory HT used in bright daylight or under a cloudy sky.
Gijs

Gijs van Ginkel said:

.....

That is one thing, but our visual system seems also capable of balancing our perception of color, so the colors perceived on a cloudy day are by our visual system perceived not different from the visual observation of colors on a sunny day despite the spectral difference between these two light regimes.......
Gijs

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Not sure I either understand this correctly, or if I am understanding this as you implying that colors look the same to our eyes in cloudy and sunny conditions- then I disagree.

I know here where I live in the often damp, foggy, rainy PNW of the US, the colors and foliage looks almost Totally different when observed during cloudy days vs. sunny days.

I think you folks are referring to what is called "color constancy." A brief introduction can be found here: Color Constancy

Be careful ... deep swamp.

Ed

Stephen b,
What I am trying to say is that blue stays blue, red stays red and green stays green both under a cloudy sky and a sunny sky, only the brightness of the colors is different.
Gijs

Gijs van Ginkel said:

Stephen b,
What I am trying to say is that blue stays blue, red stays red and green stays green both under a cloudy sky and a sunny sky, only the brightness of the colors is different.
Gijs

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Got ya!

Thank you for the clarification- makes perfect sense.

Gijs van Ginkel said:

Holger,
Thank you for your comments that makes things more clear. I agree that we have to take into account the spectral sensitivity of our eyes in understanding how images are perceived given a certain color pattern, which a tranmission spectrum offers. That is one thing, but our visual system seems also capable of balancing our perception of color, so the colors perceived on a cloudy day are by our visual system perceived not different from the visual observation of colors on a sunny day despite the spectral difference between these two light regimes. So that puzzles me and if you have some explanation how that would apply to measured transmission spectra, than I would be happy. I did not observe great color differences with the Victory HT used in bright daylight or under a cloudy sky.
Gijs

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Gijs,

I would love to hear your impressions [in some detail] regarding the HT - perhaps in comparison to the SV or SLC-HD.

james holdsworth,
I have the intention to do what you ask for,but unfortunately my days have only 24 hours and there are many things/persons which/who take my time, but you will get my observations, please be patient.
Gijs

Gijs van Ginkel said:

james holdsworth,
I have the intention to do what you ask for,but unfortunately my days have only 24 hours and there are many things/persons which/who take my time, but you will get my observations, please be patient.
Gijs

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Looking forward to it.....

elkcub said:

I think you folks are referring to what is called "color constancy." A brief introduction can be found here: Color Constancy

Be careful ... deep swamp.

Ed

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Correct - color constancy is the reason why we identify colors correctly under varying light conditions - even indoors under artificial light. A kind of "white-balance" of our visual system. As mentioned by Stephen b, such a mechanism is never perfect, of course, and in critical situations the ambient light (or, a considerable color tint of the optics, for that matter) may lead to misinterpretations.

Cheers,
Holger

Amazing where discussions of a little 8x32 have led!

Would it complicate matters overly, if a goodly proportion of us it seems, have eyes with different colour casts on each side?

The majority seem to have a left eye with a bluish-green cast, and the right eye with a brownish-red cast, though not at all times for all people (I like to imagine us with natural versions of those cheap 20th century blue and red cellophane 3D glasses).

I wouldn't even like to begin to speculate on correlations between left, or right-handed, preference for clockwise or counter-clockwise focus to infinity, or indeed even northern, or southern-hemisphere !!


Chosun :gh: