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- Magnification and move vision:

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Old Monday 6th January 2020, 23:00   #51
Rico70
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Originally Posted by Alexis Powell View Post
I'm w/Rico70 on one detail. All else being equal, I don't think that it's correct to say a 25x binocular vibrates more than a 7x bin which vibrates more than a 1x bin. The 7x bin simply shows the vibration magnified 7x more than the 1x.
Hi Alexis, I think our friend WJC is saying the same thing (I believe).

Rather, the cardinal point that still does not seem well defined and focused is this:
someone thinks and believes (sometimes or often without having ever tried it), that a 25x provides less detail, in proportion to a 7x.
But this undoubtedly clashes with what instead we agree I, Alexis and WJC (and also others, together with Physics).

Here we should not defend a compromise choice that was considered by the military more than 70 years ago, even if this could prove useful (and I doubt it) to someone for the action of the birder on every occasion. But this is not the purpose of this discussion, since as I have already said, the discussion must be valid in general, and should evaluate (at least initially) the fundamental theoretical bases on which to build a new functional idea (for different events).

I am not a birder and I could not be even if I wanted to, because in my area I would be able to identify perhaps only 40 different species of birds (on average 10-20 in a day). Despite this, I happily use binoculars to observe the local fauna as well, which for natural reasons does not come easily. So, I ask myself: how many of us can say that we normally observed Terns and Bee-eaters, when hunting for food, at distances of 10-15m?

It seems logical to me that for these events (and many others) more magnifications will be needed compared to 6x. I like it and I can also observe nature for dozens of continuous minutes freehand with the 25x (not only for 2-3 sec), satisfactorily. The important thing is that if I want to observe the more stable fauna (or the moon), I can do it in the most peaceful calm of resting the 25x on something solid and thus enjoying more details, but much more enlarged and detailed than a 6x or of an 8x.

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Old Tuesday 7th January 2020, 02:01   #52
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Hi Alexis, I think our friend WJC is saying the same thing (I believe).

Rather, the cardinal point that still does not seem well defined and focused is this:
someone thinks and believes (sometimes or often without having ever tried it), that a 25x provides less detail, in proportion to a 7x.
But this undoubtedly clashes with what instead we agree I, Alexis and WJC (and also others, together with Physics).

Here we should not defend a compromise choice that was considered by the military more than 70 years ago, even if this could prove useful (and I doubt it) to someone for the action of the birder on every occasion. But this is not the purpose of this discussion, since as I have already said, the discussion must be valid in general, and should evaluate (at least initially) the fundamental theoretical bases on which to build a new functional idea (for different events).

I am not a birder and I could not be even if I wanted to, because in my area I would be able to identify perhaps only 40 different species of birds (on average 10-20 in a day). Despite this, I happily use binoculars to observe the local fauna as well, which for natural reasons does not come easily. So, I ask myself: how many of us can say that we normally observed Terns and Bee-eaters, when hunting for food, at distances of 10-15m?

It seems logical to me that for these events (and many others) more magnifications will be needed compared to 6x. I like it and I can also observe nature for dozens of continuous minutes freehand with the 25x (not only for 2-3 sec), satisfactorily. The important thing is that if I want to observe the more stable fauna (or the moon), I can do it in the most peaceful calm of resting the 25x on something solid and thus enjoying more details, but much more enlarged and detailed than a 6x or of an 8x.
Again there appears to be a contradiction here. One of the problems inherent in Rico's posts is the stated idea he can freehand high magnification binoculars. Lots of people, including me, are understandably perplexed by this. I dug out a 20x60 Pentax porro, the largest magnification binocular I have. I most assuredly am unable to use it in the manner I think Rico is saying. Again, maybe the translation is somehow inaccurate.
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Old Tuesday 7th January 2020, 07:15   #53
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Again there appears to be a contradiction here. One of the problems inherent in Rico's posts is the stated idea he can freehand high magnification binoculars. Lots of people, including me, are understandably perplexed by this. I dug out a 20x60 Pentax porro, the largest magnification binocular I have. I most assuredly am unable to use it in the manner I think Rico is saying. Again, maybe the translation is somehow inaccurate.
The largest magnification bino I have is a Conquest 15x56 and very early in my time with it, in a fit of enthusiasm, I took it as my only bino on trip to a nature reserve about 100 miles away and then to a weekend away on the coast. In the nature reserve, resting my elbows on the hide/blind shelves the image was tolerable if a little 'twitchy' but my time on the coast was mostly a disaster because I could only hold the bino steady for a minute or two. This might have been OK if all I wanted to do was identify species and tick them off a list, providing no difficult species turned up requiring extended viewing. But I enjoy watching behaviour rather than listing species and my performance those days with the 15x was lamentable. Since then the big Conquest has accompanied us on holidays and set up on a tripod indoors overlooking sea lochs and bays and has give wonderful views. So I am absolutely clear that I could not enjoy the image through a 25x bino that was hand-held. However I am of retired age and do not have the muscle-mass I had when I was younger. Maybe a stronger person who can train themselves to tolerate the image can be happy with it.

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Old Tuesday 7th January 2020, 17:09   #54
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...the cardinal point that still does not seem well defined and focused is this:
someone thinks and believes (sometimes or often without having ever tried it), that a 25x provides less detail, in proportion to a 7x...
I think there is plenty of agreement that it is possible for 25x to show more detail than 7x in hand-held viewing. We just don't agree that it is a good overall choice for hand-held viewing.

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...we should not defend a compromise choice that was considered by the military more than 70 years ago, even if this could prove useful (and I doubt it) to someone for the action of the birder on every occasion...
Many birders already agree that the "military" ideal compromise for handheld magnification of 7x is not accurate as a practical limit for birding. We tend to think more towards 10x (but certainly not 12x or 15x or 25x!). Even so, we often still choose 7x or 8x for advantages of FOV and DOF.

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...But this is not the purpose of this discussion, since as I have already said, the discussion must be valid in general, and should evaluate (at least initially) the fundamental theoretical bases on which to build a new functional idea (for different events)...
I think that many of us are open to the idea of considering different magnifications and viewing techniques for different purposes.

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...I am not a birder and I could not be even if I wanted to, because in my area I would be able to identify perhaps only 40 different species of birds (on average 10-20 in a day). Despite this, I happily use binoculars to observe the local fauna as well, which for natural reasons does not come easily...
I understand that birding, exclusively, might not be satisfying if you live in an area with very low species diversity. Around here, it is possible to find over 200 species in a day in spring, and in winter we hope for over 75 species on a good day. Still, I have many other interests besides birding.

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...So, I ask myself: how many of us can say that we normally observed Terns and Bee-eaters, when hunting for food, at distances of 10-15m? It seems logical to me that for these events (and many others) more magnifications will be needed compared to 6x. I like it and I can also observe nature for dozens of continuous minutes freehand with the 25x (not only for 2-3 sec), satisfactorily. The important thing is that if I want to observe the more stable fauna (or the moon), I can do it in the most peaceful calm of resting the 25x on something solid and thus enjoying more details, but much more enlarged and detailed than a 6x or of an 8x...
As a point of fact, please know that in the course of birding, even small birds are routinely detected and identified at distances well beyond 10-15 m. I think 75 m is perhaps a more realistic measure of the typical limit for the high-comfort zone for detection and identification of most small birds in a familiar setting. Bee eaters are medium sized birds and terns are large.

That point aside, I'm sure many of us agree that higher magnifications are often useful for natural history pursuits. That's why we often own and use scopes on tripods. Believe me, we'd love it to be true that we could use 25x scopes or binoculars handheld. We'd love not to have to haul that tripod. And our conviction that we can't hand hold 25x is not a result of being brainwashed by the 7x military paradigm. Rather, it is based on our own practical experience. We've tried to hand hold 25x and found that we failed. I know that I have! My Nikon 27x50ED Fieldscope with Velbon 455 Ultra tripod and RRS bh-25 head is extraordinarily compact and lightweight for travel, but if I could get away with leaving the tripod behind, I would! For daily birding, I have little trouble managing an ~80 mm scope on a sleek but robust CF tripod with good fluid head, so I'm not much tempted to go lighter by hand-holding a conventional optic or by carrying along high power IS binoculars in addition to my 8x standard bins.

So if you really want to move the discussion forward and convince us of the feasibility of a
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...a new functional idea (for different events)...
, you are going to have to explain more about how it is that you are able to use 25x for extended comfortable hand-held observation. If you don't tell us more, and if you don't tell us something new and surprising that we can do ourselves, we are going to conclude that we've already been where you are (i.e. that we've already tried what you are doing) and have found the quality of viewing unsatisfactory by our standards, or that you have superhuman abilities that we cannot employ. For example, consider Steve C's reaction:
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...One of the problems inherent in Rico's posts is the stated idea he can freehand high magnification binoculars. Lots of people, including me, are understandably perplexed by this. I dug out a 20x60 Pentax porro, the largest magnification binocular I have. I most assuredly am unable to use it in the manner I think Rico is saying...
So Rico70, again, if you want to get traction with your argument, you've got to tell us more. We want to believe what you are saying, but just hoping that what you are saying is true has not been sufficient for us to find the promised land. Some, like Troubador, have already (in the past) tried a leap of faith
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The largest magnification bino I have is a Conquest 15x56 and very early in my time with it, in a fit of enthusiasm, I took it as my only bino on trip ...and my performance those days with the 15x was lamentable...
and still didn't find the heavenly paradise you describe for yourself and (in past posts) for naive users who haven't been corrupted by the nothing-higher-than-7x dogma (or blasphemy, depending on your perspective).

I think you've got to tell us more if any of us are to follow this discussion any further with any real interest.

--AP

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Old Tuesday 7th January 2020, 17:40   #55
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Excellent post, Alexis. You have the patience of Job!
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Old Wednesday 8th January 2020, 01:22   #56
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I'm glad to see this discussion start to get somewhere. I think we all want to understand the experience Rico is describing handholding 25x or even 100x, even if it may not be relevant to our own usual purposes. A while ago Binastro raised a question that occurs to me also: for how long at a time can you actually get this highly detailed view of the target, and how is that useful or enjoyable?

Rico, do you find yourself largely having to remember all the details that you so briefly glimpsed? Are you sure that you remember them accurately? Do you perhaps have what's called photographic memory that would allow this?

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Old Wednesday 8th January 2020, 05:19   #57
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Once one has viewed steady, high powered images (say 15x and more), the value of a good support system is made exceedingly clear, whether it is IS, a tripod, or some other means. I have had difficulty in this thread fully grasping whether Rico has been saying that 25X hand held will yield more detail, just because of the increased magnification, or whether it is actually a useful, everyday practice to handhold optics at that magnification. If its the latter, I don't agree at all, admittedly based on a lack of experience with such an endeavor, save comparing Canon 15 x50 views with the IS on and off, as well as using a spotting scope at 25x while sitting down, with it in my lap.

Since he's already made clear he is no birder, then I'm not sure what the basis of his rationalizations are for this thread. Some of the magnification 'jumps' seem like useful measures for thinking practically about relationships between binoculars and fixed mag. eyepieces on a scope, when one is hauling all that gear around. Otherwise, the supposition that just because one might fleetingly be able to see 'more' detail at 25x handheld, than without is more or less a beer drinking discussion, not a practical piece of advice for field use. Alexis has already said it better, which I do appreciate. Thank you Alexis! And, Rico, I'm not sure that google translate is doing you any favors in this, or other threads. I do appreciate your enthusiasm though!

Cheers to all,

Bill

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Old Wednesday 8th January 2020, 08:48   #58
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Brilliant post Alexis and you didn't mention astigmatism once!

Cogently explained in a friendly and constructive manner.

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Old Wednesday 8th January 2020, 14:16   #59
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Brilliant post Alexis and you didn't mention astigmatism once!...
...or variable-ratio focus, ...or "darting eyes", ...or hang!

Seriously though, I may give this one more go to address some points in the original post that caught my interest.

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Old Wednesday 8th January 2020, 16:26   #60
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Familiarity with the target helps with glimpsed views.

We have persistence of vision, even without a photographic memory.

My understanding is that photographic memory needs more than a fraction of a second.

In the 1950s when nearly all aircraft looked different, I could reliably identify numerous aircraft in 1/10th second, sometimes even 1/30th second or less.
But this depended on the orientation of the aircraft.
With some orientations I might not be sure in even ten seconds.

With unfamiliar targets it is my opinion that with a hand held 100x binocular the true fine detail would just not be identified at all.

I do not accept that hand holding a 100x binocular will ever reveal the detail that the 100x binocular has on a firm tripod.

The tune has changed in some of these claims.
Initially, only hand held, but now with a firm base.
These are quite different.

I use high power binoculars, but when at all possible they have the firmest support I can find without using a tripod.

Touching both front barrels on window glass, using the window frame, if possible below and to the side.

Telephone catalogues, car roof, fence, tree, lamp post etc.

Being flat on my back on the grass.

Then there is tying a cord to the end of a long lens and standing on the other end.

With cameras the strap was always the right length to wrap round my elbow and keep the strap taught without breaking it.

With the G15 camera I jam the camera gently against the window. The body is flush against the window frame, angled to the sky.
The one second exposures have sharp stars even at maximum zoom on display.
The shutter is squeezed with no movement. The grip of my hand is firm but not stressed.

Basically, it is technique.

But I don't accept the premise that hand holding a 100x binocular can ever give the detail that would be seen if the binocular was firmly tripod mounted.
Assuming of course that the binocular works at 100x.

B.
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Old Wednesday 8th January 2020, 17:56   #61
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Rico70,

At the risk of giving this thread insanely more attention than it probably deserves, I'm going to inquire into a few points in your original treatise that didn't come up in our later exchange, but that contributed to my interest in your claims in the first place.

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...there is also a general line at the basis of the geometric rules on optical resolution, which is valid for anyone and which establishes that in order to discriminate-separate-resolve at a minimum level the details barely perceptible with the eye vision naked (to the limit of individual possibilities), the magnification must be increased by at least 3 times as much (that is, at least 3 times the starting optical resolution)...
In spite of your further explanation (beyond what I have quoted above) and citation, I can't understand how what you are claiming here could be true, because the real world usually isn't composed of details that differ in magnitude from each other to any regular degree (i.e. resolvable detail of the world is "analog", not "digital", not quantized). Consequently, assuming that a binocular (or any supplementary lens) can resolve finer detail than the eye, _any_ increase in magnification should bring more details beyond the threshold of the eye's resolving ability, and consequently allow them to be perceptible.

I will grant you that when it comes to seeing impressively more detail by eye through optics, or capturing it with a digital camera, 3x the magnification or megapixels, is, in my experience, a nice increment. Going from two eyes to one eye with a 5x monocular is a nice boost. From eyes to 7x or 8x bins is a giant leap. From 8x bins to 20x scope is a nice step, and 8x bins to 30x scope is a nice big step. By contrast, the jumps from 7x to 8x, or 8x to 10x, or 30x to 60x are generally unsatisfying to me, even though each of them certainly yields more detail. Again, these are just personal preferences, and these preferences and experiences do nothing to challenge my observation of the continuous increase in detail-revealing performance that comes with increased magnification (provided the instrument has higher resolving power than the eye).

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...starting from the 1x reference of the naked eye vision, the subsequent magnification values, with minimum steps of useful resolution (3.24x), will be indicated in a rounded way, such as: 3.3x 10x 34x 110x 360x ... etc. These represent the basic values, but also essential to obtain at each subsequent step, that minimum increase of detail necessary to solve the previous level. The intermediate levels to these (that is, in steps of 1.8x), become mostly useless...
Again, you seem to think that the details of the world are somehow quantized. Even if the detection system is digital or somehow organically quantized, the world being observed (usually) _isn't_, nor is the possible level of magnification used to deliver the light to that detection system. Consequently, all intermediate levels of detail exist and are available to be resolved by each tiny increment in magnification.

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...Raising the minimum factor 3.24x (3.24^2) to power, the visibility of the detail reaches a higher plane, made with steps of approximately 10.5x. This corresponds to the increase necessary, in order to be able to adequately resolve what is absolutely not possible to solve or even perceive, with the naked eye (1x)...
...10x magnification is in practice the minimum necessary to be able "to enter the binocular high definition", since it is the first of the scale able to show us what is normally impossible even just to glimpse with the naked eye...
...8x is unable to adequately enlarge the details barely perceptible with the naked eye vision...
What????? _You_ can't see (much) more through binoculars than _you_ can see with your naked eyes until you reach 10x magnification?! You can't be serious! You can't have made this statement based on accurate appraisal of your own observational experience. Unless you have a quantized retina and are living a world of quantized levels of detail, what you have said here cannot be true.

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...the topic under discussion: the visibility of the blur (moved-stir). Often it is unjustly attributed to magnification, the fault of a blurred and shaky vision...
I agree that it would be a mistake to attribute to magnification the blur that is a result of the eye/brain's inability to process a rapidly moving (i.e. shaking) image. Magnification does not cause shaking blur, it just allows the shaking to be seen as blur since fine details (relative to the overall structure in view) that exist in the world and that are resolved within the (perceptibly) shaking image are moving too fast to be reliably seen.

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...So for some users, the larger magnification means being able to look further and aim for a sharper detail, addressing the higher values ​​(useful for any sightings and recognitions) aware of having to improve the stability of the binoculars and their vision, with training and devising functional solutions...
Agreed that users who are able to hold their bins more steady than the average person, or who somehow have above average ability to visually process a moving image, will be able to make good use of higher than average binocular magnifications.

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...While for other users it seems to be more a question of making the blur they themselves produce invisible, reducing the magnification at all costs, until everything appears "stable" to their sight... ...1 - the less magnified vision may appear even firmer and thus be more restful, but that same vision will certainly (and also mathematically) be equally less detailed...
Agreed that by reducing magnification until shaking is not bothersome that one is placing a strong limit on magnification, and thus the amount of detail that the binoculars will be able to deliver to the eye above its own unaided abilities. As an aside, I also grant that this cap on magnification, traditionally around 7-10x, is far below the 25-40x magnifications that a reasonably-sized (hand-holdable) telescope or binocular can easily be made to achieve and deliver (with adequate brightness, eye-relief) very comfortably to the eye, whether the eye/brain can make sense of the image or not.

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...the user, with his ability or inability to static stabilization (kineticism) and with any biopsychic abilities or difficulties of his vision... ...it will also be essential to learn to better stabilize your hands and especially your binoculars, also training your vision to follow the moving images... ...Unfortunately, stable vision through binoculars is the consequence of various individual factors that cannot be generalized...

...Unfortunately, not everyone has the same ability to exploit these bio-psychic and kinetic possibilities. And for some users, 10x binoculars already appear difficult to manage, although in practice most of the binoculars users have never seriously tried to use the 12x to 25x tools...
Agreed that users differ quite a bit in their abilities to hold binoculars steady or to make visual sense of a moving image. I don't think it is true that we on BirdForum accept the ~10x limit via dogma--I think most of us _have_ tried to hand-hold higher magnifications and have failed. I also think that members of the general public (i.e. those who are not on BirdForum), when purchasing binoculars, also often try higher powers. In my experience, most naive buyers want binoculars to work like what they see portrayed in movies (often ~100x!), so they are extremely disappointed with 8x or 10x when they try those powers. They immediately want much higher magnifications, which they quickly discover that they cannot hand-hold. This soon leads to interest in spotting scopes, which they are disappointed to find are bulky and require tripods, are hard to use, are expensive, and are _still_ not as powerful as what they were wanting.

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...The eye has automatic image stabilization capabilities, capable of hiding part of the blur, using the saccadic and tracking movements and also with the tricks of its perceptive system. But this system becomes more efficient by increasing the blur magnification. And so, with magnifications much greater than 10x, where the shake will have a much larger size, the eye will be gradually facilitated to stabilize the images almost automatically. Of course, training and habit will help improve the results obtained, which will also become useful for the use of lower magnification binoculars. Of course the stabilization of the eye works more in daytime terrestrial observations, compared to night vision, but in practice it will be paradoxically easier to hold 100x binoculars freehand rather than 10x. Since, at 100x, the shake becomes so "large" that there is no longer a shake, but only a wide movement, which is certainly easier to manage and "absorb" for the eye, compared to the "too fine" shake of the 10x. And in fact, using 100x freehand binoculars, it will be possible to see all those fine details that are impossible to see, both at 10x but also at 30x, even if these binoculars were stabilized on a tripod.
The same criterion is valid in a lesser way also for 25x and 34x magnifications so that, having the subjects at the right distance and a sufficient field of view, it will also be possible to easily attach and follow many subjects in rapid movement, as can be done with low magnification binoculars...
OK, this is the bit that you really need to explain more. Moreover, you need to explain how to employ or develop the techniques that you claim to use.

The way that I have understood this passage is as follows. You are arguing that, for two reasons, that details that are only just resolved by the eye in a 10x view will be easier to perceive when they are instead magnified 100x, even when hand-held. The first reason [with which I agree] is that at 100x, those details will now be very comfortably within the eye's ability to resolve them (and indeed, many more finer details will be available than at 10x). The second reason is that, since at 100x the rapid tiny shaking movements due to hand-holding will become translated into apparently long motions [To that, I agree], that you think [And here, I disagree] will make seeing the details easier because they can now be tracked rather than being lost in too fine and too rapid motion.

I don't see how such tracking, either by the eye as a whole or through retinal processing, would be facilitated by magnification. Although the proportional-to-the-overall-scene amount of motion stays the same with magnification (especially if there is, as in this thought example, no limit on FOV), with magnification both the apparent amount of motion and the apparent _speed_ of the motion increase. In my experience, the speed of that motion quickly increases with magnification beyond the limits of my retinal ganglia and brain's ability to process it, and so the detail is lost in the perceptual phenomenon that we all know as motion blur.

I might agree that _if_ I were able to look at the same flat scene through a 100x binocular that had the same true FOV as a 10x binocular, both very rapidly shaking in a randomized but limited and held on target (on average) way, that (I imagine--I haven't really thought this through fully) that I might be able to see more details, because (again, I imagine that) the 100x scene would look much the same as the 10x view, just larger. What are perceived as points of light composing the 10x perceived view will now be perceived as motion-blurred discs of light composing the 100x perceived view. Some details not visible in the 10x view would become visible in the 100x view as they would be perceived as small motion-blurred discs of light within the larger discs of light that correspond to what were points in the 10x view. Again, I'm not sure I've thought this through correctly, so I don't trust my imagination. Regardless, none of what I have described in this paragraph matches your descriptions, nor does it, in my experience, match the specifications of available binoculars, the FOV limits of my eyes, or the movement/vibration characteristics of my hand-held views. Consequently, it doesn't for me have practical application. But I'd be happy to be convinced otherwise!

--AP

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Old Wednesday 8th January 2020, 19:37   #62
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Alexis

You deserve a medal. Many thanks for posting this fine assessment.

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Old Thursday 9th January 2020, 00:15   #63
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I think there is plenty of agreement that it is possible for 25x to show more detail than 7x in hand-held viewing.
What you say, finally cheers me up. And I can believe you, because you are confirming it to me now. While I am still a little skeptical of some others (of yours ) who have always supported your opposite.

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We just don't agree that it is a good overall choice for hand-held viewing.
25x is just one example that I bring, and I can also understand that it is a personal choice based on needs other, than the common birder.
The main knot, you've already untied it above. And it was one of the goals, when I opened this "campaign", because I found opposite beliefs.

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Originally Posted by Alexis Powell View Post
- Many birders already agree that the "military" ideal compromise for handheld magnification of 7x is not accurate as a practical limit for birding. We tend to think more towards 10x.

- I think that many of us are open to the idea of considering different magnifications and viewing techniques for different purposes.

- I'm sure many of us agree that higher magnifications are often useful for natural history pursuits.
These are all positive statements.

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As a point of fact, please know that in the course of birding, even small birds are routinely detected and identified at distances well beyond 10-15 m. I think 75 m is perhaps a more realistic measure of the typical limit for the high-comfort zone for detection and identification of most small birds in a familiar setting.
The detection and identification of the birds mentioned can also be done with the naked eye, from distances of 75m. What I meant to say is that there are also other events other than detection and identification, so it may be necessary or more interesting to use higher magnifications than 8x and 10x. While on the other hand, on this I found many conflicts and received several reactions of "denial". You are now saying the same things I said.

I believe there is more a mental limit than an enlargement limit. We set the limit, based on what we want and what we are willing to trade.
Having 25x (of equal brightness) means having larger dimensions and weight of the binoculars, greater visibility of the shake and less field of view than 8x.
But also greater magnification and greater detail of the same objects observed. So it will be more useful and more suitable for long range observations. If you don't need "long range", you don't need 25x.

There is no rule that can impose the use of one or the other, but only a personal need and therefore an arbitrary choice. This is not a race (at least for me). I have already understood that the greater details of the 25x are more interesting than those of the 8x. I have already understood and already explained how magnification works, the exit pupil, the combination of these two values and the possibilities of exploiting them. If then for any reason, someone fails to exploit 25x and decides not to use it, I don't know if I can do much more for him.
I can certainly wish him to have fun with what he has chosen.

Here you ask me something more:
"you will need to explain more about how 25x can be used for extended and comfortable manual observation"
I can add something fundamental in my opinion, which I have already said but which has not been taken into consideration by anyone: the trembling vision derives mainly from the movement of the lenses of the objectives. Stop those, the image will also stop.
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Old Thursday 9th January 2020, 00:35   #64
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I'm glad to see this discussion start to get somewhere. I think we all want to understand the experience Rico is describing handholding 25x or even 100x, even if it may not be relevant to our own usual purposes. A while ago Binastro raised a question that occurs to me also: for how long at a time can you actually get this highly detailed view of the target, and how is that useful or enjoyable?

Rico, do you find yourself largely having to remember all the details that you so briefly glimpsed? Are you sure that you remember them accurately? Do you perhaps have what's called photographic memory that would allow this?
I don't think I have a particular photographic memory, but the idea is good and it certainly connects well with the structure of vision as it is described in medical texts.
What I see in these questions (I don't know if it is correct) is the curiosity typical of when the topic is not clear, but interesting.
Certainly, as I have already said, the physical and perceptive (automatic and unconscious) capacities of sight, find merit in these situations (100x type). Observation time is limited only by the weight and shape of the binoculars. If it weighed max 400g and had the structure of a 7x35 Porro-prism, it would be usable without time limits.
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Old Thursday 9th January 2020, 00:50   #65
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With unfamiliar targets it is my opinion that with a hand held 100x binocular the true fine detail would just not be identified at all.

I do not accept that hand holding a 100x binocular will ever reveal the detail that the 100x binocular has on a firm tripod.
Not only can I agree with you, but I'm sure it should be unacceptable regardless of the magnification.
So it will be unacceptable even with 3x 5x 8x 10x etc ...

Last edited by Rico70 : Thursday 9th January 2020 at 01:28.
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Old Thursday 9th January 2020, 00:54   #66
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I don't think I have a particular photographic memory, but the idea is good and it certainly connects well with the structure of vision as it is described in medical texts.
What I see in these questions (I don't know if it is correct) is the curiosity typical of when the topic is not clear, but interesting.
Certainly, as I have already said, the physical and perceptive (automatic and unconscious) capacities of sight, find merit in these situations (100x type). Observation time is limited only by the weight and shape of the binoculars. If it weighed max 400g and had the structure of a 7x35 Porro-prism, it would be usable without time limits.
Let's get specific...
What model binoculars (mag/aperture) are you talking about?
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Old Thursday 9th January 2020, 01:32   #67
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Let's get specific...
What model binoculars (mag/aperture) are you talking about?
The binoculars to which you refer, is a fancy binoculars to give an example.

If instead you refer to the 25x, it is the Celestron SkyMaster 25x70 which that actually weighs 1350g (and not 1200g as I had written elsewhere).
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Old Thursday 9th January 2020, 01:53   #68
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In spite of your further explanation ... Unless you have a quantized retina and are living a world of quantized levels of detail, what you have said here cannot be true.
This is a complex point. Both to explain and to understand.
I understand what you're objecting to. And I assure you that I don't have bionic (quantized) vision!

Here I make a small (but important) clarification.
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...with a digital camera, 3x the magnification or megapixels...
To increase the sensor detail (spatial resolution) by 3x, it is necessary to increase the Megapixel by 9x (not 3x).

Now I try to answer the rest too (go slowly, please).
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Old Thursday 9th January 2020, 02:17   #69
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I agree that it would be a mistake to attribute to magnification the blur that is a result of the eye/brain's inability to process a rapidly moving (i.e. shaking) image.
Here unfortunately many translation errors have passed to the control of my Italian eyes. Replace, blurs with shake, please.

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I don't think it is true that we on BirdForum accept the ~10x limit via dogma--I think most of us _have_ tried to hand-hold higher magnifications and have failed.
Okay, so I take it. It seems to me that I have been reading BF for a year or more, but I can trust your greater experience.

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I also think that members of the general public (i.e. those who are not on BirdForum), when purchasing binoculars, also often try higher powers...
On this I am not so sure. In my experience, the shopkeeper always offers 8x and hardly has magnifications greater than 10-12x. But my experience here is small.

To be continued...
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Old Thursday 9th January 2020, 03:11   #70
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...To increase the sensor detail (spatial resolution) by 3x, it is necessary to increase the Megapixel by 9x (not 3x)...
This detail is a triviality, but please know that although I understand your point, my point was a more general one, which is to say that I, very roughly, take 3-fold increases in these properties to translate to worthwhile and significant increases in performance--30x versus 10x binoculars, 18 megapixels versus 6 megapixels--even though they do not translate to equivalent increases in resolution.

--AP
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Old Thursday 9th January 2020, 03:12   #71
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OK, this is the bit that you really need to explain more. Moreover, you need to explain how to employ or develop the techniques that you claim to use.
I don't know the technique, it's all automatism of the eye and visual perception (it was instinctive for me right from the start). But I noticed that it helps to improve a lot of habit and familiarity with vision in motion. On the contrary, from what I understand that the birder does. He looks for stable images avoiding any vision in motion. And in doing this, he gets used to the firm vision.

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The way that I have understood this passage is as follows. You are arguing that, for two reasons, that details that are only just resolved by the eye in a 10x view will be easier to perceive when they are instead magnified 100x, even when hand-held. The first reason [with which I agree] is that at 100x, those details will now be very comfortably within the eye's ability to resolve them (and indeed, many more finer details will be available than at 10x).
Yes

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The second reason is that, since at 100x the rapid tiny shaking movements due to hand-holding will become translated into apparently long motions [To that, I agree], that you think [And here, I disagree] will make seeing the details easier because they can now be tracked rather than being lost in too fine and too rapid motion.
I don't think. I see it with my eyes.

But perhaps here we need to repeat a fundamental thing that seems not yet clear.
If your hand shake is raised to 10x as a 120 arcosec large figure (for example), when you look in a 100x, that same shake will be 1200" (10 times as large).
- And if this were not understood and accepted (at least theoretically), it would not be possible to continue further.

The wide movement of the 100x will now be so wide that the saccadic and tracking muscles are able to chase it. This causes a more stable and complete image to arrive to the retina, than the eye can stabilize at 10x. And therefore, the details visible with the 100x, which in proportion are 10 times as much, will have an even greater value than the 10x.
It is not a matter of FOV.

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What are perceived as points of light composing the 10x perceived view will now be perceived as motion-blurred discs of light composing the 100x perceived view.
No, it does not! The detail of the 100x is real and is 10 times greater than that of the 10x.
The 100x image is not a 10x photo enlarged 10 times!
If anything, the opposite is true: the 10x image is a 100x photo reduced by 10 times (e.g. from 100Mp to 1Mp) and therefore with 10 times less detail to see.


EDIT: I corrected an incorrect number.

Last edited by Rico70 : Thursday 9th January 2020 at 07:42. Reason: EDIT: I corrected an incorrect number.
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Old Thursday 9th January 2020, 05:00   #72
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The wide movement of the 100x will now be so wide that the saccadic and tracking muscles are able to chase it. This causes a more stable and complete image to arrive to the retina, than the eye can stabilize at 10x. And therefore, the details visible with the 100x, which in proportion are 10 times as much, will have an even greater value than the 10x.
It is not a matter of FOV.
Alexis is bringing up FOV because at 100x it's so narrow that in practice, your target will easily swing out of view entirely, defeating your claimed ability to follow it while in larger-scale motion. Do you not find that?

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Old Thursday 9th January 2020, 05:07   #73
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Rico70,

as a general reply to your responses thus far, it doesn't seem to me that you experience motion blur as I and others do. As I noted before, magnifying the image increases both the apparent amount of motion as well as the _speed_ of the motion. It is the latter that is so destructive to the magnified view. The speed is too fast for me to process most of the time. When you watch movies, does it blur into continuous motion for you, or do you see stop-action frames? :)

--AP
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Old Thursday 9th January 2020, 08:03   #74
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This detail is a triviality...
Sorry Alexis, I indicated that because it's not trivial. I understood what you meant, but since the point of my initial explanation was focused on the pixels and the sensor, that detail becomes central.
Hope you can understand.

The human eye is not a quantum detector. But in any case, the retina is made up of sensitive elements of finite number, distributed "similarly" to the grid of a photographic sensor. The spatial resolution of the eye is determined by the retina, which does not reach the maximum potential of the optical counterpart (crystalline, cornea, moods, etc.).
But then, the maximum visual acuity is generally lower than the retinal value, because the bottleneck is the optic nerve, which cannot 100% carry all that data.

Thus. In the 3x example, the 18Mp becomes 2Mp (not 6Mp).

I think it is better for everyone else, to indicate the correct corresponding value, so misunderstandings or misinterpretations derived from reading will be avoided.


I like the work you have done, and I am reading everything willingly

Last edited by Rico70 : Thursday 9th January 2020 at 08:27.
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Old Thursday 9th January 2020, 08:08   #75
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Alexis is bringing up FOV because at 100x it's so narrow that in practice, your target will easily swing out of view entirely, defeating your claimed ability to follow it while in larger-scale motion. Do you not find that?
No, Tenex. For what Alexis was talking about, the FOV was not inherent. And not even for my sight of the pigeon at 100x, which was stationary on the ledge of the house and was comfortably within the field of vision.

Last edited by Rico70 : Thursday 9th January 2020 at 08:22.
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