Who mentioned 9.75x ?
Something bigger than 50mm but smaller than a 56 would be a step up from Swaro EL SV and Leica Uvid which only go to 50mm. Yes that would leave SLC being bigger at 56.
We will have to wait and see.
Lee
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Zeiss 11x50 Victory Ht (1 Viewer)
- Thread starter Vespobuteo
- Start date
Who mentioned 9.75x ?
Something bigger than 50mm but smaller than a 56 would be a step up from Swaro EL SV and Leica Uvid which only go to 50mm. Yes that would leave SLC being bigger at 56.
We will have to wait and see.
Lee
james holdsworth
Consulting Biologist
I know it makes no sense, but I could see no difference in brightness [daylight / dusk] between an 8x56 Night Owl and my 8x42 HT. Only in near full dark could a difference be discerned, and then it was slight.
It isn't my eyes either, as I can see vast differences in brightness between the FL / HT / HD.
henry link
Well-known member
This makes perfect sense if your eyes can't dilate to much more than 5mm.
james holdsworth
Consulting Biologist
But they can, I had them tested last year and they dilate to 6 mm. I'm not that old, Henry.
Perceptions of ''brightness'' are a bit more tricky than implied, at least as it applies to individuals. Some see vibrant colour as brighter, some see more shadow detail as brighter, some see brighter whites and pale areas as brighter. The difference in what I perceive to be brightness between my 8x32 HD and 8x42 HT are stark - daylight/dusk/dark [the HD always looks dingy and dull in comparison], so I can't explain my observations with the 8x56.
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james holdsworth
Consulting Biologist
I agree. I'm editing the post to make it less ''pissy.''
I guess we should try to arrive at some sort of standard reference of ''brightness'', something that we can discern in the field, as opposed to transmission plots. This forum is littered with observations of smaller aperture binoculars appearing as bright or even brighter than those of bigger aperture. I know that I can detect as little as 5%, at least I think I can, as I can see a clear difference between the SV 8.5 and the HT.
Are all of these observations down to observers eyes no longer dilating fully or is it a trick of the transmission curve of the binocular? Back to the HT again, it may only be a few percent brighter than a comparable FL, but the difference appears much greater. If you glean the big HT thread, you will see numerous others have the same perception....ex... Torview thought the 8X42 HT was brighter than the 7x42 FL and so on. The Binomania review of the HT suggested the HT was equal in brightness to the two 8x56's they compared in most situations.
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James
Although a 3% difference in brightness is much quoted as the minimum that folks can perceive, at least one Zeiss designer puts that at 2.5%.
But your observation that more intense colours may be perceived as brighter is a good one, but then one starts to ask 'what makes a colour be transmitted more intensely?'.
And HT whites are definitely whiter than FL whites. Since white is the sum of all light frequencies then whiter must by definition mean brighter?
Or has watching the movie 'Gravity' distorted my already eccentric thought processes?
Lee
Gijs van Ginkel
Well-known member
Dear all,
Brightness is a complex phenomenon and is not only governed by the amount of light coming into the eye, but also by the color balance of that light. Because of the discusion around this topic I have written a review paper entitled "Color vision, brightness, resolution and contrast in binocular images" (because this discussion is coming up again and again it may be worthwile to read it). It is published on the WEB-site of House of Outdoor under the topic "Verrekijkers"and that contains a separate chapter "verrekijkers testen en vergelijken". In that last chapter you can find this review paper.
For those of you who are also interested in the history of the development of optical theory and the production of binoculars in The Netherlands and Belgium from 1608-2013: there is also a powerpoint which illustrates that topic describing the optical companies Bleeker, Old Delft, Nedinsco (an important Zeiss plant in The Netherlands from 1921-1944 and independent from Zeiss from 1944 until now) and OIP in Belgium.
Gijs
Brightness is a complex phenomenon and is not only governed by the amount of light coming into the eye, but also by the color balance of that light. Because of the discusion around this topic I have written a review paper entitled "Color vision, brightness, resolution and contrast in binocular images" (because this discussion is coming up again and again it may be worthwile to read it). It is published on the WEB-site of House of Outdoor under the topic "Verrekijkers"and that contains a separate chapter "verrekijkers testen en vergelijken". In that last chapter you can find this review paper.
For those of you who are also interested in the history of the development of optical theory and the production of binoculars in The Netherlands and Belgium from 1608-2013: there is also a powerpoint which illustrates that topic describing the optical companies Bleeker, Old Delft, Nedinsco (an important Zeiss plant in The Netherlands from 1921-1944 and independent from Zeiss from 1944 until now) and OIP in Belgium.
Gijs
. Dear Gijs,
are these topics in Dutch?
are they easy to find?
some Old Delft optics that I've tested are amazingly good in particular a 13 cm aperture military mirror lens.
I think that the principle of some mirror lenses was independently discovered in the Netherlands.
are these topics in Dutch?
are they easy to find?
some Old Delft optics that I've tested are amazingly good in particular a 13 cm aperture military mirror lens.
I think that the principle of some mirror lenses was independently discovered in the Netherlands.
brocknroller
porromaniac
True enough, however, many birders are middle aged and older and cannot utilize a 6mm exit pupil, let alone a 7mm one. So for them, there would be no difference in exit pupil sizes between an 8x42 and an 8x56 because of their entrance pupil size.
The only argument that makes sense for an 8x56 for those folks, which includes me, is what Henry mentioned in his 8x56 FL review, namely, that the 8x56 will have less aberrations and better resolution. Given how good the resolution of 8x42 alphas are these days and their 90%+ light transmission, the extra weight doesn't seem worth it, to me, at least.
But perhaps I just don't know what I'm missing. If the 8x56 FL makes the 8x32 SE's tack sharp image seem "mushy" by comparison, as Henry stated in his review, then perhaps it would be worth carrying the extra weight (with a binoharness, of course) as long as I could get the same FOV, which I could with an 8x56 FL or 8x56 SLC (don't see the specs on SONA's Website yet, but it's supposed to be about the same as the FL).
Most 8x56 bins have about a degree less FOV than their 8x42 counterparts, which for birding, takes them out of consideration.
Brock
Gijs van Ginkel
Well-known member
Binastro, post 110,
these topics are all in english and they are easy to find on the WEB-site of House of Outdoor. Go to "Verrekijkers"and then the left row says "verrekijkers testen en vergelijken"and the lowest two papers are in English.
Gijs
these topics are all in english and they are easy to find on the WEB-site of House of Outdoor. Go to "Verrekijkers"and then the left row says "verrekijkers testen en vergelijken"and the lowest two papers are in English.
Gijs
henry link
Well-known member
James,
Sorry for late reply. I'm quoting your original post again since it seems the most relevant.
Obviously you recognize that these observations are hard to swallow. If your pupil dilation is really 6mm in low light, how could around 30% more light reaching the eye be seen as only "slightly" brighter (8x56 Night Owl over 8x42 HT), while around 2% more light reaching the eye is seen as "vastly" brighter (8x42 HT over 8x42 FL)? You're right, it doesn't make sense.
Just out of curiosity, how was your maximum dilation tested? Could your eye pupil have been smaller than maximum dilation under the low light conditions of the 8x56 vs 8x42 comparison?
Henry
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