To better understand the issue, we should first try to understand what are the foundations that govern this topic.
Let's start by saying that magnification means magnifying the visible detail and that the cause of a blurred or shaky vision observable through the binoculars used freehand, it cannot and must never be attributed to the greater magnification.
Therefore, there is in fact no magnification value which due to itself is the limiting factor of the observed or observable detail.
The causes are fundamentally attributable to the user (who in no case will remain rigid as a block of granite), but also to the limits of visibility through the atmosphere (when this enters into question, generally for long-range observations) and others causes such as the disparity of ergonomics and optical quality, between the binoculars in comparison (but these disparities are subjective and therefore useless causes in the general objective discourse).
Let's try to clear the mind, to make room for the principle that any magnification value assigned to optical observation instruments, such as magnifying glasses, microscopes, telescopes, telescopes, sights, aiming optics, rangefinders, eyepieces, eyeglasses, eyeglasses, binoculars, etc., it always refers to the vision with the naked eye. This, in fact, is the absolute reference, and is equivalent to the value of 1x (that is, 1 magnification).
The magnification of each binoculars, indicates how many times larger we will see the objects, compared to the apparent dimensions observed with the naked eye. So, for example, each 10x binocular increases the apparent linear measurements of objects by 10 times, such as the diameter of the disk of the full Moon, which will appear 10 times greater than that visible to the naked eye. And this also means a proportional increase in visible detail, equal to 10 times as much, similarly to having increased the optical resolution of our visual system by 10 times.
The math is not an opinion!
Since the resolution of the observed details is directly proportional to the magnification value, it will be logical that in order to detect certain details in normal lighting conditions, a very specific minimum magnification is needed, which is appropriate for the purpose.
And the question is clearly mathematical, as it all depends on the actual size and observation distance of the object.
But, with the same observation conditions and of course also the quality of the binoculars used, the precise value of the magnification necessary to read certain details, will depend substantially on the individual value of the visual acuity of each observer (where, the visual acuity is in in this case the value equivalent to what the optical resolution is for all optical observation instruments, such as binoculars).
Visual acuity values between normal individuals can vary by a maximum of 2x, from 10 tenths to 20 tenths. But 60% of the population has on average a maximum visual acuity of 14 tenths, which is the middle way between the normal value 10/10 and the maximum value 20/10. Thus, the most common differential factors will be between 1.2x and 1.8x. And just to give an example, the same detail that user A (with 12 tenths) can detect using 10x binoculars, user B (with 18 tenths) could detect it using binoculars of just about 7x (all things being equal, quality , ergonomics, etc.).
This immediately suggests that no golden rule can ever indicate a unique, good and right magnification value, which is ideal for everyone.
But on the contrary, that the choice of magnification will be absolutely a completely personal matter, and that it will be determined by so many other factors that I struggle to list them all, among which we will find the very important needs for use and therefore, the various individual needs.
-------------------------
Having said that, however, 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).
That is, in order to effectively separate-discriminate two adjacent light points (like two nearby stars) or two consecutive white lines in a test with alternating black and white lines, at least three retinal photoreceptors are required. A similar example is given by the spatial resolution of digital cameras, based on the quantity of pixels needed to be able to discriminate the same test with alternating black and white lines. And in fact, the results of the research on the estimation of the radial movement of the focus (FRM - Journal of Vision August 2016, Vol. 16, 12. doi: 10.1167 / 16.2.12), indicate that [...] The standard deviation the Gaussian RF profile is one third of the distance between the centers of two consecutive RF [...] confirming in part a similarity between the functioning of the photographic sensor and the functioning of the ocular retina (analogy between eye and camera).
And since the magnification directly describes the increase in optical resolution compared to viewing with the naked eye (1x), a 2x binoculars which doubles the resolution, doubling the size of the objects and its details, will not be able to solve at a minimum level sufficient, that detail barely perceptible to the naked eye. But you will need to use at least 3x binoculars instead.
Again for geometric reasons, a passage of 3.24x (given by the power of the factor 1.8x) represents that minimum reliable step, in order to arrive in a certain way to the higher level of detail visibility. And then 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, although they are still usable or preferable in place of other values that are too close together. And they can be rounded to: 2x 6x 20x 60x 200x 640x ... etc.
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). Where the various plans will be translated with the enlargement steps rounded to: 10x 110x 1200x ... etc.
Magnification scale, in steps of 1.8x (rounded values): 1x 2x 3.3x 6x 10x 20x 34x 60x 110x 200x 360x 640x 1200x ... etc.
From all this, it is easy to see that the 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 . That is, the 10x binoculars manages to bring directly to attention, that detail that would like to solve our ocular fovea, in careful observation (the fovea is that central retinal area where the maximum density of diurnal receptors resides, and of average amplitude between 4 ° and 6 ° of the visual field).
Thus, while the 12x is able to increase the detail in a more evident way than the 10x, the 8x is unable to adequately enlarge the details barely perceptible with the naked eye vision. And for this reason, instruments with magnifications lower than 10x will be preferable at smaller distances and to take advantage of the greater amplitude of the visual field (when possible), while magnifications greater than 10x will be proportionally suitable for observing smaller and smaller objects and / or further away, or where more details are required (typically in ornithological, safari, astronomy, etc.). This is also the main reason for 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. And this also leads to believe in an illusory way, that freehand management has a maximum magnification value. While everything depends exclusively on the user and his inability to stabilize binoculars (not only by improving physical support, but also by using eye stabilization).
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 or accepting any compromises.
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 (which is actually impossible!). And so far there is nothing wrong. A choice like this may also be justified, but the important thing is that then it does not lead to believe, or worse, to want to argue, that in doing so it is possible to see better and more detailed, since it would be only a mere illusion from incompetent.
The purpose of the binoculars is undoubtedly to enlarge the details, and it is clear that this will also proportionally highlight any hand shake, which could disturb the observation. But the blur of the hand is precisely the blur of the user, and not of the binoculars or its magnification. Therefore, the user's blur will in any case always be present, regardless of the magnification used, be it 6x or 12x (for example). With the only difference that the blur will appear doubly visible in the 12x binoculars compared to the one visible in the 6x (as per physical laws). And that is, both the detail and the blur visible, will be equally proportionate to the value of the magnification used.
But understanding this irrefutable fact is very important. Since, one must also be aware that:
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. And for this, useless for the purpose of detecting more details.
2 - the cause of any loss of detail due to instability or blur is to be attributed only and exclusively to the limited capacity of the users and not to the possible greater enlargement of the binoculars. On the contrary, on the contrary, it is always preferable to be able to increase the magnification.
3 - it is not by reducing the magnification that the binoculars stabilize. In doing so, only detail is lost.
4 - the maximum limit of detail observed with a particular binocular, exclusively and once again dictates it, the user, with his ability or inability to static stabilization (kineticism) and with any biopsychic abilities or difficulties of his vision binocular.
5 - to increase the visible detail it is understandably necessary to have to increase the magnification, but 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. Even many of us have difficulties in binocular observation alone: Cit. [...] the majority of subjects, albeit asymptomatic, have problems concerning binocular vision (Heterophoria and Fixation Disparity) and therefore compromise their daily lives, from the simplest things like playing sports, to activities that require greater attention and visual commitment, such as reading or studying [...] or for example, observing in binoculars.
Of course, it is possible to say that as the magnifications increase, the user-generated shake will become increasingly visible to the eye.
And so, while the vision with binoculars up to 6x still appears fairly stable and "without" visible shake, the vision with values greater than 9x, will be more often visibly shake. But binoculars with magnification up to 6x, appear easier to handle freehand, because it is easier for anyone to hide their instability from use. While, the typical shake with very fine structure present at 10x, will be concretely visible by anyone (especially in the observation of the starry sky, in the way of fixing a single point).
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. 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. Often, also because few light and good quality binoculars are sold, with magnifications greater than 15x.
I firmly believe that everyone must judge the various binoculars trying every magnification, using their own eyes and hands, with an open mind, without being conditioned by the commonplaces of others. And rather trying to understand with intelligence, how to improve the stability of the observations and obtain the detail sought. Knowing in advance that ergonomics, weight balance, ease of controls and precise optical adaptation of the instrument are all very important, if not fundamental, factors that will influence stability management, always improving the quality of our observations . So much so that at the same magnification, the ergonomic differences of the various models could lead to a particular binocular being even "much more stable" than another. But only in this case, will it really be possible to talk about the merits or demerits of the instrument. And for this reason, it is always better to try binoculars in person and be able to make many direct comparisons between the various models, finding the differences, evident or perhaps substantial, regarding ergonomics and good management of free-hand stability.
Let's start by saying that magnification means magnifying the visible detail and that the cause of a blurred or shaky vision observable through the binoculars used freehand, it cannot and must never be attributed to the greater magnification.
Therefore, there is in fact no magnification value which due to itself is the limiting factor of the observed or observable detail.
The causes are fundamentally attributable to the user (who in no case will remain rigid as a block of granite), but also to the limits of visibility through the atmosphere (when this enters into question, generally for long-range observations) and others causes such as the disparity of ergonomics and optical quality, between the binoculars in comparison (but these disparities are subjective and therefore useless causes in the general objective discourse).
Let's try to clear the mind, to make room for the principle that any magnification value assigned to optical observation instruments, such as magnifying glasses, microscopes, telescopes, telescopes, sights, aiming optics, rangefinders, eyepieces, eyeglasses, eyeglasses, binoculars, etc., it always refers to the vision with the naked eye. This, in fact, is the absolute reference, and is equivalent to the value of 1x (that is, 1 magnification).
The magnification of each binoculars, indicates how many times larger we will see the objects, compared to the apparent dimensions observed with the naked eye. So, for example, each 10x binocular increases the apparent linear measurements of objects by 10 times, such as the diameter of the disk of the full Moon, which will appear 10 times greater than that visible to the naked eye. And this also means a proportional increase in visible detail, equal to 10 times as much, similarly to having increased the optical resolution of our visual system by 10 times.
The math is not an opinion!
Since the resolution of the observed details is directly proportional to the magnification value, it will be logical that in order to detect certain details in normal lighting conditions, a very specific minimum magnification is needed, which is appropriate for the purpose.
And the question is clearly mathematical, as it all depends on the actual size and observation distance of the object.
But, with the same observation conditions and of course also the quality of the binoculars used, the precise value of the magnification necessary to read certain details, will depend substantially on the individual value of the visual acuity of each observer (where, the visual acuity is in in this case the value equivalent to what the optical resolution is for all optical observation instruments, such as binoculars).
Visual acuity values between normal individuals can vary by a maximum of 2x, from 10 tenths to 20 tenths. But 60% of the population has on average a maximum visual acuity of 14 tenths, which is the middle way between the normal value 10/10 and the maximum value 20/10. Thus, the most common differential factors will be between 1.2x and 1.8x. And just to give an example, the same detail that user A (with 12 tenths) can detect using 10x binoculars, user B (with 18 tenths) could detect it using binoculars of just about 7x (all things being equal, quality , ergonomics, etc.).
This immediately suggests that no golden rule can ever indicate a unique, good and right magnification value, which is ideal for everyone.
But on the contrary, that the choice of magnification will be absolutely a completely personal matter, and that it will be determined by so many other factors that I struggle to list them all, among which we will find the very important needs for use and therefore, the various individual needs.
-------------------------
Having said that, however, 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).
That is, in order to effectively separate-discriminate two adjacent light points (like two nearby stars) or two consecutive white lines in a test with alternating black and white lines, at least three retinal photoreceptors are required. A similar example is given by the spatial resolution of digital cameras, based on the quantity of pixels needed to be able to discriminate the same test with alternating black and white lines. And in fact, the results of the research on the estimation of the radial movement of the focus (FRM - Journal of Vision August 2016, Vol. 16, 12. doi: 10.1167 / 16.2.12), indicate that [...] The standard deviation the Gaussian RF profile is one third of the distance between the centers of two consecutive RF [...] confirming in part a similarity between the functioning of the photographic sensor and the functioning of the ocular retina (analogy between eye and camera).
And since the magnification directly describes the increase in optical resolution compared to viewing with the naked eye (1x), a 2x binoculars which doubles the resolution, doubling the size of the objects and its details, will not be able to solve at a minimum level sufficient, that detail barely perceptible to the naked eye. But you will need to use at least 3x binoculars instead.
Again for geometric reasons, a passage of 3.24x (given by the power of the factor 1.8x) represents that minimum reliable step, in order to arrive in a certain way to the higher level of detail visibility. And then 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, although they are still usable or preferable in place of other values that are too close together. And they can be rounded to: 2x 6x 20x 60x 200x 640x ... etc.
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). Where the various plans will be translated with the enlargement steps rounded to: 10x 110x 1200x ... etc.
Magnification scale, in steps of 1.8x (rounded values): 1x 2x 3.3x 6x 10x 20x 34x 60x 110x 200x 360x 640x 1200x ... etc.
From all this, it is easy to see that the 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 . That is, the 10x binoculars manages to bring directly to attention, that detail that would like to solve our ocular fovea, in careful observation (the fovea is that central retinal area where the maximum density of diurnal receptors resides, and of average amplitude between 4 ° and 6 ° of the visual field).
Thus, while the 12x is able to increase the detail in a more evident way than the 10x, the 8x is unable to adequately enlarge the details barely perceptible with the naked eye vision. And for this reason, instruments with magnifications lower than 10x will be preferable at smaller distances and to take advantage of the greater amplitude of the visual field (when possible), while magnifications greater than 10x will be proportionally suitable for observing smaller and smaller objects and / or further away, or where more details are required (typically in ornithological, safari, astronomy, etc.). This is also the main reason for 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. And this also leads to believe in an illusory way, that freehand management has a maximum magnification value. While everything depends exclusively on the user and his inability to stabilize binoculars (not only by improving physical support, but also by using eye stabilization).
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 or accepting any compromises.
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 (which is actually impossible!). And so far there is nothing wrong. A choice like this may also be justified, but the important thing is that then it does not lead to believe, or worse, to want to argue, that in doing so it is possible to see better and more detailed, since it would be only a mere illusion from incompetent.
The purpose of the binoculars is undoubtedly to enlarge the details, and it is clear that this will also proportionally highlight any hand shake, which could disturb the observation. But the blur of the hand is precisely the blur of the user, and not of the binoculars or its magnification. Therefore, the user's blur will in any case always be present, regardless of the magnification used, be it 6x or 12x (for example). With the only difference that the blur will appear doubly visible in the 12x binoculars compared to the one visible in the 6x (as per physical laws). And that is, both the detail and the blur visible, will be equally proportionate to the value of the magnification used.
But understanding this irrefutable fact is very important. Since, one must also be aware that:
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. And for this, useless for the purpose of detecting more details.
2 - the cause of any loss of detail due to instability or blur is to be attributed only and exclusively to the limited capacity of the users and not to the possible greater enlargement of the binoculars. On the contrary, on the contrary, it is always preferable to be able to increase the magnification.
3 - it is not by reducing the magnification that the binoculars stabilize. In doing so, only detail is lost.
4 - the maximum limit of detail observed with a particular binocular, exclusively and once again dictates it, the user, with his ability or inability to static stabilization (kineticism) and with any biopsychic abilities or difficulties of his vision binocular.
5 - to increase the visible detail it is understandably necessary to have to increase the magnification, but 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. Even many of us have difficulties in binocular observation alone: Cit. [...] the majority of subjects, albeit asymptomatic, have problems concerning binocular vision (Heterophoria and Fixation Disparity) and therefore compromise their daily lives, from the simplest things like playing sports, to activities that require greater attention and visual commitment, such as reading or studying [...] or for example, observing in binoculars.
Of course, it is possible to say that as the magnifications increase, the user-generated shake will become increasingly visible to the eye.
And so, while the vision with binoculars up to 6x still appears fairly stable and "without" visible shake, the vision with values greater than 9x, will be more often visibly shake. But binoculars with magnification up to 6x, appear easier to handle freehand, because it is easier for anyone to hide their instability from use. While, the typical shake with very fine structure present at 10x, will be concretely visible by anyone (especially in the observation of the starry sky, in the way of fixing a single point).
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. 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. Often, also because few light and good quality binoculars are sold, with magnifications greater than 15x.
I firmly believe that everyone must judge the various binoculars trying every magnification, using their own eyes and hands, with an open mind, without being conditioned by the commonplaces of others. And rather trying to understand with intelligence, how to improve the stability of the observations and obtain the detail sought. Knowing in advance that ergonomics, weight balance, ease of controls and precise optical adaptation of the instrument are all very important, if not fundamental, factors that will influence stability management, always improving the quality of our observations . So much so that at the same magnification, the ergonomic differences of the various models could lead to a particular binocular being even "much more stable" than another. But only in this case, will it really be possible to talk about the merits or demerits of the instrument. And for this reason, it is always better to try binoculars in person and be able to make many direct comparisons between the various models, finding the differences, evident or perhaps substantial, regarding ergonomics and good management of free-hand stability.
Last edited: