WJC
Well-known member
Bill,
I think subjective focus and sharpness are a function of the optics transfer functions, contrast at various scales, false color, glare, sharpness across the field and a bunch of other factors, and also of the ability of each binocular to maintain sharpness when focused closer than infinity, which is not an obvious property.
An interesting side effect of buying binoculars, for me, has been a huge improvement in my ability to discriminate detail at a distance. My eyes got trained within a few weeks, to the point where now I see little reason to use the binoculars most of the time!
I know that as an engineer I shouldn't say such things, but usually with these high-end psychophysiological instruments - binoculars, camera optics, loudspeakers, headphones pianos, computer screens and TVs- the user feeling becomes as important to the customer-base as the tech performance and is hard to quantify.
By accident, I tested a bunch of alphas on some crows at about 500m, and had no problem focusing with any of them, static or in flight, Zeiss, Swaro or Leica.
It's quite possible that some people get something out of fiddling with the focus knob, and also that field curvature on some binoculars has something to do with it. I know that birds are always no-problem sharp on my Ultravid HD, and so is infinity, but roof lines never "snap" and drive me crazy when I try to "feel" the texture of stones and chimneys. I would be delighted on a comment about this, it's my main "official" use of my binoculars and what they do least well in fact. I can see very car and pedestrian a mile away, but the statues on cathedrals and inscriptions on monuments simply don't "pop".
Edmund
190528
Hi, Edmund:
You said, “It's quite possible that some people get something out of fiddling with the focus knob ...”
That comment was RIGHT ON!
I knew a fellow who, each time he would speak in church, would incessantly shift the microphone like a racecar driver. Once in a 12-minute talk, he moved it more than 60 times. Did his height change? It did not. Did the podium change its height? It did not. Did any of those 60+ settings alter the content of what he had to say or the volume thereof ... substantially, anyway? It did not. Obviously, the useless exercise provided some unknown something for him.
As far as “snapping” into focus, Lee has the basics of an answer for you. To push it a little farther, let’s look at those statues. From top to bottom they are made of bright and dim promontories, recesses, and flat areas, separated, sometimes by only inches. Your brain is doing the best it can to quantify things for you, but you are just being too hard on it. Looking through an “ALPHA” is not going to change the physiological realities of you not being Superman.
This is the kind of topic that can be talked about and speculated to death. My original comment concerning “staring” I KNOW to be true. I have proven it through conversations with many customers, using binoculars ranging from ALPHAS to OMEGAS. I didn’t set out to conduct scientific testing. However, over time, the database builds. I wanted so badly to become an optical engineer. But I didn’t have the mathematical sense to become one. Thus, I have had to satisfy myself with having devised some of the routines in some of the best optimization programs and knowing that when seasoned engineers flounder with the nuts and bolts of the technology, they often call on me. That most certainly is not to say that my seat-of-the-pants engineering (Zemax-EE) is on par with even the dumbest engineer out there. But when you have dealt with certain facets of the technology every day for years, you can’t escape learning something. :cat:
Bill
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