Chosun Juan
Given to Fly
Nicely put Bill :t: I hope the OP takes note :cat:As people come and go on Internet forums, ranging from experts to newbies in any given aspect of the forum’s focus, it’s impossible to put any topic to rest. But, in order to push the level of understanding up the ladder a bit, I want to try approaching the idea of image brightness. To help drive home my thoughts, I will start with a story.
I was having breakfast at a friend’s house when we were about fifteen. His mother gave him a glass for his milk that had 2 or 3 drops of water in it. His teenage butt became unreasonable and he castigated his mother. But, was anything really accomplished? Yes, it was. He embarrassed his mother. He embarrassed me. And, he made himself look like an intolerant fool. Perhaps a better question would have been: was anything beneficial accomplished. It wasn’t.
We should first consider milk is already 95-97% water and then consider how much a few drops of additional water is going to change the flavor or nutritional value of the milk. Of course, there would be a difference. But, who has the biological equipment to recognize that difference? Again, much flutter—no flight.
The same is true with IMAGE BRIGHTNESS in instruments of similar quality, aperture, and magnification. The real contributing factor in image brightness is the size of the EXIT PUPIL and the spot presented to the receptors in the eye.
AR coatings, glass types, prism types, and eyepiece types DO play a part. However, as in the example above, they play such a small part—AGAIN WHEN COMPARING SIMILAR INSTRUMENTS—as to create endless discussions of useless consequence. And, would the findings of ONE HOUR be the same for the same individual under different physiological and environmental conditions, the next? Different tests performed at different times with different subjects having different ranges of accommodation for different visual acuities under different conditions will produce different results.
If one wants a brighter image than that available using his or her current binocular ... buy another binocular. All the rhetoric in the world is not going to change the physics of the matter.
Please, if anyone has any empirical information to contradict what I have just said—hey, I want to learn, too, and not spread inaccuracies—share it with me. Share it here that others might take advantage of the information. That’s empirical information and not a collection of opinions. :cat:
Just a thought,
Bill
When EP's and Brightness in two instruments are so similar that we are getting to the thresholds of human perception, the question of which one is 'better' as the sun dips over the ol' horizon and off to warm (or fry! someone else's cockles, becomes a bit like shuffling deck chairs on the Titanic ..... there might be some momentary advantage - but ultimately you're not going to be seeing much! :eek!:
I've compared two bins during that lovely time of afternoon as the light engoldens and the shadows lengthen and with the p**fteenth in difference between the Swift Audubon 8.5x44 ED and another similarly parametered bin, I can detect a difference (on the day, and for a particular MOMENT, and considering whether or not I've had carrots for lunch! :cat: ..... but it's like horse race:-
It's Brightness by half a length, but here comes EP - It's Brightness - it's EP, it's EP - it's neck and neck ,oh and with a late charge down the outside it's their progeny - Effective Brightness by a short half head!
Ultimately, other factors come in to play, like the feel and balance of the instrument, the ergonomics, and the particular 'flava' of the AR Coating recipe and resultant colour rendition (unless you prefer color! and how you like all of those. ..... :cat:
"And, would the findings of ONE HOUR be the same for the [SAME] individual under different physiological and environmental conditions, the next? Different tests performed at different times with different subjects having different ranges of accommodation for different visual acuities under different conditions will produce different results." ..... definitely a Second Ed paragraph right there Bill :t:
Finally, let the OP be informed enough about the Zeiss x54 HT that they go and read the threads here on BF of reputable testers who've eyeballed the thing and had some consequential things to say ..... ! Fair warning. :cat:
Chosun :gh:
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