You are riding on a train and looking out the window... Pillars standing along the rails flash by. Buildings located a few tens of meters from the railway track run back more slowly. And very slowly, reluctantly, the houses and groves that you see in the distance, somewhere near the horizon, fall behind the train...
Why does this happen? This question is answered in Fig. 1. While the direction to the telegraph pole, when the observer moves from the first position to the second, changes by a large angle P 1, the direction to a distant tree will change by a much smaller angle P 2. The speed at which the direction of an object changes when the observer moves is less, the further away the object is from the observer. And from this it follows that the magnitude of the angular displacement of an object, which is called parallactic displacement or simply parallax, can characterize the distance to the object, which is widely used in astronomy.
Of course, it is impossible to detect the parallactic displacement of a star while moving along the earth's surface: the stars are too far away, and the parallaxes during such movements are far beyond the possibility of their measurement. But if you try to measure the parallactic displacements of stars when the Earth moves from one point in its orbit to the opposite (that is, repeat observations with an interval of six months, Fig. 2), then you can quite count on success. In any case, the parallaxes of several thousand stars closest to us were measured in this way.
Parallax displacements measured using the Earth's annual orbital motion are called annual parallaxes. The annual parallax of a star is the angle (π) by which the direction to the star will change if an imaginary observer moves away from the center solar system to the Earth's orbit (more precisely, to the average distance of the Earth from the Sun) in a direction perpendicular to the direction of the star. It is easy to understand from Fig. 2 that the annual parallax can also be defined as the angle at which the semimajor axis of the earth’s orbit, located perpendicular to the line of sight, is visible from the star.
WITH annual parallax The basic unit of length adopted in astronomy for measuring distances between stars and galaxies is the parsec (see Distance units). The parallaxes of some nearby stars are given in the table.
For closer celestial bodies - the Sun, Moon, planets, comets and other bodies of the Solar System - parallactic displacement can also be detected when the observer moves in space due to the daily rotation of the Earth (Fig. 3). In this case, parallax is calculated for an imaginary observer moving from the center of the Earth to the equator point at which the star is on the horizon. To determine the distance to the star, calculate the angle at which the equatorial radius of the Earth is visible from the star, perpendicular to the line of sight. This parallax is called daily horizontal equatorial parallax or simply daily parallax. The daily parallax of the Sun at an average distance from the Earth is 8.794″; the average daily parallax of the Moon is 3422.6″, or 57.04′.
As already mentioned, annual parallaxes can be determined by direct measurement of the parallactic displacement (the so-called trigonometric parallaxes) only for the nearest stars located no further than several hundred parsecs.
However, the study of stars for which trigonometric parallaxes have been measured has revealed a statistical relationship between the type of spectrum of a star (its spectral class) and absolute magnitude (see “Spectrum-luminosity” diagram). Having extended this dependence also to stars for which the trigonometric parallax is unknown, they were able to estimate the absolute magnitudes of the stars by the type of spectrum, and then, comparing them with visible magnitudes, astronomers began to estimate the distances to the stars (parallaxes). Parallaxes determined by this method are called spectral parallaxes (see Spectral classification of stars).
There is another method for determining distances (and parallaxes) to stars, as well as star clusters and galaxies - using variable stars of the Cepheid type (this method is described in the article Cepheids); such parallaxes are sometimes called Cepheid parallaxes.
παραλλάξ , from παραλλαγή , “change, alternation”) - a change in the visible position of an object relative to a distant background depending on the position of the observer.Knowing the distance between observation points D ( base) and the displacement angle α in radians, you can determine the distance to the object:
For small angles:
The reflection of the lantern in the water is significantly shifted relative to the practically unchanged sun
Astronomy
Daily parallax
Daily parallax (geocentric parallax) is the difference in directions to the same body from the Earth’s center of mass (geocentric direction) and from a given point on the Earth’s surface (topocentric direction).
Due to the rotation of the Earth around its axis, the position of the observer changes cyclically. For an observer located at the equator, the parallax base is equal to the radius of the Earth and is 6371 km.
Parallax in photography
Viewfinder parallax
Viewfinder parallax is the discrepancy between the image visible in an optical non-mirror viewfinder and the image obtained in the photograph. Parallax is almost unnoticeable when photographing distant objects, but is quite significant when photographing close objects. It arises due to the presence of a distance (basis) between the optical axes of the lens and viewfinder. The parallax value is determined by the formula:
,where is the distance (basis) between the optical axes of the lens and viewfinder; - focal length of the camera lens; - distance to the aiming plane (object).
Viewfinder parallax (sight)
A special case is sight parallax. Parallax is not the height of the sight axis above the barrel axis, but the error in the distance between the shooter and the target.
Optical parallax
Rangefinder parallax
Rangefinder parallax is the angle at which an object is visible when focusing using an optical rangefinder.
Stereoscopic parallax
Stereoscopic parallax is the angle at which an object is viewed with both eyes or when photographed with a stereoscopic camera.
Time parallax
Temporal parallax is a distortion of the shape of an object by parallax that occurs when shooting with a camera with a curtain shutter. Since exposure does not occur simultaneously over the entire area of the photosensitive element, but sequentially as the slit moves, when shooting fast moving objects their shape may be distorted. For example, if an object moves in the same direction as the shutter slit, its image will be stretched, and if in the opposite direction, it will be narrowed.
Story
Galileo Galilei suggested that if the Earth revolved around the Sun, this would be noticeable by the variability of parallax for distant stars.
The first successful attempts to observe the annual parallax of stars were made by V. Ya. Struve for the star Vega (α Lyrae), the results were published in 1837. However, scientifically reliable measurements of the annual parallax were first carried out by F.V. Bessel in 1838 for the star 61 Cygni. The priority of the discovery of the annual parallax of stars is recognized by Bessel.
see also
Literature
- Yashtold-Govorko V. A. Photography and processing. Photography, formulas, terms, recipes. Ed. 4th, abbr. - M.: “Iskusstvo”, 1977.
Links
- The ABC's of Distances - a review of measuring distances to astronomical objects.
Wikimedia Foundation.
2010.:Synonyms
See what "Parallax" is in other dictionaries: - (astro.) the angle formed by visual lines directed at the same object from two different ones. points. Once the parallax of an object and the distance between two points from which this object was observed is known, then the distance of the object from... ... Dictionary foreign words
Russian language - (from the Greek parallaxis deviation) 1) a visible change in the position of an object (body) due to the movement of the observer’s eye. 2) In astronomy, a visible change in the position of a celestial body due to the movement of the observer. There are parallax,...
Big Encyclopedic Dictionary parallax - the apparent displacement of the object in question when the angle of its perception changes or the observation point moves. Dictionary of a practical psychologist. M.: AST, Harvest. S. Yu. Golovin. 1998. parallax...
Great psychological encyclopedia PARALLAX, the angular distance at which celestial object appears to be displaced in relation to more distant objects when observed from opposite ends of the base. Used to measure the distance to an object. Star parallax... ...
Scientific and technical encyclopedic dictionary PARALLAX, parallax, husband. (Greek parallaxis evasion) (astro.). An angle that measures the apparent displacement of a luminary when an observer moves from one point in space to another. Daily parallax (the angle between the directions to the star from a given location... Dictionary
Ushakova - (from the Greek parallaxis deviation) the apparent displacement of the object in question when the angle of its perception changes ...
Psychological Dictionary - (from the Greek parallaxis deviation) in aviation, astronautics, lateral displacement of the plane of the final orbit aircraft relative to the launch point, usually measured along a great circle arc from the launch point of the aircraft to the wake... ...
- (from the Greek parallaxis deviation) in astronomy, a change in the direction of the observer astr. object when the observation point is shifted equal to the angle under the eye from the center of the object, the distance between the two positions of the observation point is visible. Usually used P.,... ... Physical encyclopedia
Noun, number of synonyms: 1 offset (44) Dictionary of synonyms ASIS. V.N. Trishin. 2013… Synonym dictionary
Big Encyclopedic Dictionary- The apparent change in the position of an object in relation to another object when the point of view changes... Dictionary of Geography
Due to the widespread use among people close to shooting sports (a sniper is also an athlete) and hunting, a large number of different optical instruments (binoculars, spotting scopes, telescopic and collimator sights), questions increasingly began to arise related to the quality of the image provided by such instruments, as well as factors affecting aiming accuracy. Since more and more of our people are educated and/or have access to the Internet, the majority have somewhere heard or seen words related to this problem such as PARALLAX, ABERRATION, DISTORTION, ASTIGMATISM, etc. So what is it and is it really that scary?
Let's start with the concept of aberration.
Any real optical-mechanical device is a degraded version of an ideal device, manufactured by man from some materials, the model of which is calculated based on the simple laws of geometric optics. Thus, in an ideal device, each POINT of the object under consideration corresponds to a certain POINT of the image. In fact, this is not so. A point is never represented by a dot. Errors or errors in images in an optical system caused by deviations of the beam from the direction in which it would go in an ideal optical system are called aberrations.
There are different types of aberrations. Most common the following types aberrations of optical systems: spherical aberration, coma, astigmatism and distortion. Aberrations also include the curvature of the image field and chromatic aberration (associated with the dependence of the refractive index of the optical medium on the wavelength of light).
This is what is written about various types aberrations in the general view in a textbook for technical schools (not because I cite this source because I doubt the intellectual abilities of the readers, but because the material here is presented in the most accessible, concise and competent way):
"Spherical aberration - manifests itself in the mismatch of the main foci for light rays passing through an axisymmetric system (lens, objective, etc.) at different distances from the optical axis of the system. Due to spherical aberration, the image of a luminous point does not look like a point, but a circle with a bright core and a halo weakening towards the periphery. Correction of spherical aberration is carried out by selecting a certain combination of positive and negative lenses that have the same aberrations, but with different signs. Spherical aberration can be corrected in a single lens using aspherical refractive surfaces (instead of a sphere, for example, the surface of a paraboloid of revolution or something similar - E.K.).
Coma. The curvature of the surface of optical systems, in addition to spherical aberration, also causes another error - coma. Rays coming from an object point lying outside the optical axis of the system form two mutually perpendicular
directions, a complex asymmetrical scattering spot, resembling a comma in appearance (comma, English - comma). In complex optical systems, coma is corrected together with spherical aberration by selecting lenses.
Astigmatism lies in the fact that the spherical surface of a light wave can be deformed when passing through an optical system, and then the image of a point that does not lie on the main optical axis of the system is no longer a point, but two mutually perpendicular lines located on different planes at a certain distance from each other. from friend. Images of a point in sections intermediate between these planes have the form of ellipses, one of them has the shape of a circle. Astigmatism is caused by the uneven curvature of the optical surface in different cross-sectional planes of the light beam incident on it. Astigmatism can be corrected by selecting lenses so that one compensates for the astigmatism of the other. Astigmatism (as well as any other aberrations) can also occur in the human eye.
Distortion is an aberration that manifests itself in a violation of the geometric similarity between an object and an image. It is due to the uneven linear optical magnification in different areas of the image. Positive distortion (the increase in the center is less than at the edges) is called pincushion distortion. Negative - barrel-shaped. The curvature of the image field is that the image of a flat object is sharp not in the plane, but on a curved surface. If the lenses included in the system can be considered thin, and the system is corrected for astigmatism, then the image of a plane perpendicular to the optical axis of the system is a sphere of radius R, with 1/R=<СУММА ПО i произведений fini>, where fi is the focal length of the i-th lens, ni is the refractive index of its material. In a complex optical system, field curvature is corrected by combining lenses with surfaces of different curvatures so that the value of 1/R is zero.
Chromatic aberration is caused by the dependence of the refractive index of transparent media on the wavelength of light (light dispersion). As a result of its manifestation, the image of an object illuminated by white light becomes colored. To reduce chromatic aberration in optical systems, parts with different dispersion are used, which leads to mutual compensation of this aberration..."(c)1987, A.M. Morozov, I.V. Kononov, "Optical Instruments", M., VSh, 1987 .
What of all of the above is important for our dear reader?
- Spherical aberration, coma, astigmatism and chromatic aberration can have any serious impact on the aiming accuracy of an optical sight. But, as a rule, self-respecting companies do everything in their power to correct these aberrations as much as possible. The criterion for correcting aberrations is the resolution limit of the optical system. It is measured in angular values, and the smaller it is (at equal magnification), the better the sight is corrected for aberration.
- Distortion does not affect the resolution of the sight and manifests itself sharply in some distortion visible image. Many may have encountered devices such as door peepholes and fisheye lenses in which distortion is not specifically corrected. As a rule, distortion in optical sights is also being fixed. But some presence of it in the sight, as will be said below, is sometimes very useful.
Now about the concept of parallax.
"Parallax is the apparent displacement of the observed object due to the movement of the shooter's eye in any direction; it appears as a result of a change in the angle at which the given object was visible before moving the shooter's eye. As a result of the apparent displacement of the aiming pin or crosshair, an aiming error is obtained, this parallax The error is the so-called parallax.
To avoid parallax, when aiming with a telescope, you should accustom yourself to always place your eye in the same position in relation to the eyepiece, which is achieved by using a butt stock and frequent aiming exercises. Modern weapons-grade telescopes allow you to move the eye along the optical axis of the eyepiece and to the sides of it up to 4 mm without parallactic errors in aiming.
V.E. Markevich 1883-1956
"Hunting and sporting small arms"
It was a quote from a "classic". From the point of view of a mid-century man, it is absolutely correct. But time is running... In general, in optics, parallax is a phenomenon caused by the fact that the same object is observed by one observer from different angles. Thus, the determination of range by optical rangefinders and artillery compasses is based on parallax; the stereoscopicity of human vision is also based on parallax. The parallax of optical systems is due to differences in the diameters of the exit pupil of the device (5-12 mm in modern sights) and the human eye (1.5-8 mm depending on the background illumination). Parallax exists in any optical device, even one that is maximally corrected for aberration. Another thing is that parallax can be compensated by artificially introducing aberration (distortion) into the optics of the eyepiece part of the sight so that the total distortion of the sight is zero, and the distortion of the reticle image is such that it compensates for the parallax of the sight in the entire plane of the entrance pupil. But this compensation occurs only for the image of an object located at a distance of practical infinity of the sight (the value is given in the passport). That's why some professional scopes have the so-called. parallax adjustment device (Parallax Adjust-ment Knob, Ring, etc.) Its essence is to change the distance of practical infinity, i.e. rude - focus. With non-parallax corrected scopes, it is best to actually aim with your eye exactly in the center of the scope's exit pupil.
How do you know if your scope is parallax corrected or not? Very simple. It is necessary to point the center of the sight reticle at an object located at infinity, fix the sight, and, moving the eye along the entire exit pupil of the sight, observe the relative position of the object image and the sight reticle. If the relative position of the object and the reticle does not change, then you are very lucky - the sight is corrected for parallax. People with access to laboratory optical equipment can use an optical bench and a laboratory collimator to create an infinitely distant point of view. The rest can use a sighting machine and any small object located at a distance of more than 300 meters.
The same simple method can be used to determine the presence or absence of parallax in collimator sights. The absence of parallax in these sights is a big plus, since the aiming speed in such models increases significantly due to the use of the entire diameter of the optics.
From all of the above, the conclusion suggests itself:
Dear users of optical sights! Don't bother yourself with terms like astigmatism, distortion, chromatism, aberration, coma, etc. Let this remain the lot of optical designers and calculation engineers. All you need to know about your scope is whether it is parallax corrected or not. Find out by carrying out the simple experiment described in this article.
I wish everyone a positive result.
Egor K.
Revised September 30, 2000
Sniper's Notebook
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Space is one of the most mysterious concepts in the world. If you look at the sky at night, you can see a myriad of stars. Yes, probably each of us has heard that there are more stars in the Universe than grains of sand in the Sahara. And scientists since ancient times have been reaching out to the night sky, trying to unravel the mysteries hidden behind this black void. Since ancient times, they have been improving methods for measuring cosmic distances and the properties of stellar matter (temperature, density, rotation speed). In this article we will talk about what stellar parallax is and how it is used in astronomy and astrophysics.
The phenomenon of parallax is closely related to geometry, but before we consider the geometric laws underlying this phenomenon, let’s plunge into the history of astronomy and figure out who and when discovered this property of the movement of stars and was the first to apply it in practice.
Story
Parallax as a phenomenon of changing the position of stars depending on the location of the observer has been known for a very long time. Galileo Galilei wrote about this in the distant Middle Ages. He only suggested that if it were possible to notice a change in parallax for distant stars, this would be evidence that the Earth revolves around the Sun, and not vice versa. And this was the absolute truth. However, Galileo was unable to prove this due to the insufficient sensitivity of the equipment at that time.
Closer to the present day, in 1837, Vasily Yakovlevich Struve conducted a series of experiments to measure the annual parallax for the star Vega, part of the constellation Lyra. Later, these measurements were recognized as unreliable when, in the year following Struve’s publication, 1838, Friedrich Wilhelm Bessel measured the annual parallax for the star 61 Cygni. Therefore, no matter how sad it may be, the priority of discovering the annual parallax still belongs to Bessel.
Today, parallax is used as the main method for measuring distances to stars and, with sufficiently accurate measuring equipment, gives results with minimal error.
We should move on to geometry before actually looking at what the parallax method is. And first, let’s remember the very basics of this interesting, although unloved by many, science.
Basics of geometry
So, what we need to know from geometry to understand the phenomenon of parallax is how the values of the angles between the sides of a triangle and their lengths are related.
Let's start by imagining a triangle. It has three connecting straight lines and three angles. And for each different triangle there are different angles and side lengths. You cannot change the size of one or two sides of a triangle if the angles between them remain unchanged; this is one of the fundamental truths of geometry.
Let's imagine that we are faced with the task of finding out the lengths of two sides if we only know the length of the base and the size of the angles adjacent to it. This is possible with the help of one mathematical formula that connects the values of the lengths of the sides and the values of the angles lying opposite them. So, let's imagine that we have three vertices (you can take a pencil and draw them) forming a triangle: A, B, C. They form three sides: AB, BC, CA. Opposite each of them lies an angle: angle BCA opposite AB, angle BAC opposite BC, angle ABC opposite CA.
The formula that ties all these six quantities together is:
AB / sin(BCA) = BC / sin(BAC) = CA / sin(ABC).
As we see, everything is not entirely simple. We got a sine of angles from somewhere. But how do we find this sine? We will talk about this below.
Basics of trigonometry
Sine is a trigonometric function that determines the Y coordinate of an angle plotted on a coordinate plane. To show this clearly, they usually draw coordinate plane with two axes - OX and OY - and mark points 1 and -1 on each of them. These points are located at the same distance from the center of the plane, so a circle can be drawn through them. So, we got the so-called unit circle. Now let's construct some segment with the beginning at the origin and the end at some point on our circle. The end of the segment, which lies on the circle, has certain coordinates on the OX and OY axes. And the values of these coordinates will be cosine and sine, respectively.
We found out what a sine is and how it can be found. But in fact, this method is purely graphic and was created rather to understand the very essence of what they represent trigonometric functions. It can be effective for angles that do not have infinite rational cosine and sine values. For the latter, another method is more effective, which is based on the use of derivatives and binomial calculation. It is called the Taylor series. We will not consider this method because it is quite complicated to calculate in the head. After all, fast calculations are a job for computers that are designed for this. The Taylor series is used in calculators to calculate many functions, including sine, cosine, logarithm, and so on.
All this is quite interesting and addictive, but it’s time for us to move on and return to where we left off: the problem of calculating the values of the unknown sides of a triangle.
Sides of a triangle
So, let's return to our problem: we know two angles and the side of the triangle to which these angles are adjacent. We only need to know one angle and two sides. Finding the angle seems to be the easiest: after all, the sum of all three angles of a triangle is equal to 180 degrees, which means you can easily find the third angle by subtracting the values of two known angles from 180 degrees. And knowing the values of all three angles and one of the sides, you can find the lengths of the other two sides. You can check this yourself using any of the triangles as an example.
Now let's finally talk about parallax as a way to measure the distance between stars.
Parallax
This, as we have already found out, is one of the simplest and most effective methods for measuring interstellar distances. Parallax is based on the change in the position of a star depending on its distance. For example, by measuring the angle of the apparent position of a star at one point in the orbit, and then at the one directly opposite it, we obtain a triangle in which the length of one side (the distance between opposite points of the orbit) and two angles are known. From here we can find the two remaining sides, each of which is equal to the distance from the star to our planet at different points in its orbit. This is the method by which the parallax of stars can be calculated. And not only stars. Parallax, the effect of which turns out to be very simple, despite this, is used in many of its variations in completely different areas.
In the following sections we will consider in more detail the areas of application of parallax.
Space
We have talked about this more than once, because parallax is an exceptional invention of astronomers, designed to measure distances to stars and other space objects. However, not everything is so simple here. After all, parallax is a method that has its own variations. For example, there are daily, annual and secular parallaxes. You can guess that they all differ in the amount of time that passes between the measurement stages. It cannot be said that increasing the time interval increases the accuracy of the measurement, because each type of this method has its own goals, and the accuracy of the measurements depends only on the sensitivity of the equipment and the selected distance.
Daily parallax
Daily parallax, the distance with which is determined using the angle between the straight lines going to the star of two different points: the center of the Earth and a selected point on the Earth. Since we know the radius of our planet, it will not be difficult, using angular parallax, to calculate the distance to the star, using the ones we described earlier mathematical method. Diurnal parallax is mainly used to measure nearby objects such as planets, dwarf planets or asteroids. For larger ones, use the following method.
Annual parallax
Annual parallax is still the same method of measuring distances, the only difference being that it is focused on measuring distances to stars. This is exactly the case of parallax that we considered in the example above. Parallax, with the help of which determination of the distance to a star can be quite accurate, must have one important feature: the distance from which the parallax is measured must be the greater the better. The annual parallax satisfies this condition: after all, the distance between the extreme points of the orbit is quite large.
Parallax, examples of the methods of which we have examined, certainly represents an important part of astronomy and serves as an indispensable tool in measuring distances to stars. But in fact, today they use only annual parallax, since daily parallax can be replaced by more advanced and faster echolocation.
Photo
Perhaps the most known species photographic parallax can be considered binocular parallax. You've probably noticed it yourself. If you bring your finger to your eyes and close each eye in turn, you will notice that the angle of view of the object changes. The same thing happens when shooting close objects. Through the lens, we see the image from one angle, but in reality the photo will come out from a slightly different angle, since there is a difference in the distance between the lens and the viewfinder (the hole through which we look to take the photo).
Before we finish this article, a few words about how such a phenomenon as optical parallax can be useful and why it is worth learning more about it.
Why is this interesting?
To begin with, parallax is a unique physical phenomenon that allows us to easily learn a lot about the world around us and even about what is hundreds of light years away from it: after all, with the help of this phenomenon we can also calculate the sizes of stars.
As we have already seen, parallax is not such a distant phenomenon from us, it surrounds us everywhere, and with the help of it we see as it is. This is certainly interesting and exciting, and that is why it is worth paying attention to the parallax method, if only out of curiosity. Knowledge is never superfluous.
Conclusion
So, we have figured out what the essence of parallax is, why to determine the distance to the stars it is not necessary to have complex equipment, but only a telescope and knowledge of geometry, how it is used in our body and why it can be so important for us in Everyday life. We hope the information presented was useful to you!
In motion, parallax means a change in the location of an object against some background relative to an observer who is in place. This term has gained popularity on the Internet. In particular, a website with dynamic elements in its design looks interesting. Parallax is a way of designing a page on the Internet, used by webmasters to attract a large number of visitors.
What is parallax like?
Parallax scrolling can be used vertically as well as in a straight line. The best example is Nintendo. Many of us remember with nostalgia computer games, represented by the movement of the main characters from the left side of the screen to the right. It is also possible to move downwards along a vertical straight line. often used on the web. To create a vertical slider, you can use JavaScript or CSS 3.
They are characterized by the described three-dimensional spatial effect. The game creators used several background layers. They differ in texture, and movement occurs at different speeds.
Don't think that parallax is only about creating a 3D effect. You can move existing icons on the page. Moreover, it looks quite attractive. A particularly good option is to use an individual trajectory for each of them. In this case, different icons are used, moving along different trajectories. This design attracts attention.
Picture coming to life
It's hard to find a site without images. High-quality and demonstrative drawings attract visitors. But greatest attention cause various kinds of dynamic images. Indeed, if there is movement when visiting a site, it attracts attention. The likelihood of a resource visitor returning to a dynamic image increases significantly. Did it seem like it was moving or not? Therefore, to attract visitors to the site, it is worth studying such a concept as the parallax effect.
Examples of sites with moving images:
- hvorostovsky.com;
- www.kagisointeractive.com.
As shown in the examples, the perception is improved by a menu that drops down into sub-items. This element saves time for visitors and is therefore attractive to them.
jQuery library
The term jQueryParallax defines the library of the same name. Thanks to it, it is easy to achieve the effect of movement in 3D format. jQuery creates 3D perception in a variety of ways. One of them is to move background objects horizontally and simultaneously at different speeds. This library is characterized by the presence of a large number of different kinds of properties. And the displacement described here represents only a small part of its capabilities.
The site looks quite attractive, for the creation of which various modern elements. One of them is parallax. Example sites might look like this:
- www.grabandgo.pt;
- www.fishy.com.br;
- www.noleath.com;
- buysellwebsite.com.
jParallax is represented by layers that move with mouse movement. Dynamic elements are characterized by absolute ;). Each of them is characterized by its own size and movement at an individual speed. This can be text or an image (at the request of the resource creators).
Site visitor perception
After this, a person usually pays attention to the fact that the page is designed efficiently, conveniently and competently. This fact usually commands respect. Sometimes curiosity arises to try other elements. There are a huge number of identical sites on the Internet. How to make your resource special?
If you like the design, the visitor will stay for a longer period. Thus, the likelihood that he will be attracted by the posted information increases and he will show interest. As a result, the person will take advantage of the service, product or promotional offer offered.
Favorite old games
The concept of “parallax” should be familiar to all fans of consoles of the 80s and 90s. This applies to games:
- Mario Bros.
- Mortal Kombat.
- Streets of Rage.
- Moon Patrol.
- Turtles in Time.
That is, parallax is a technique that has been used for a fairly long period. These games are indeed remembered with some nostalgia. After all, they seem to be imbued with the character of that period.
The images on the screen are created using a technique such as parallax scrolling. It is not surprising that this technique has gained well-deserved popularity. This design concept is quite warmly perceived by those who played in the 80-90s or watched their friends’ leisure time.
Parallax scrolling
Marketers of the world's leading brands have long been using various kinds of technical advances. Thus, it becomes possible to interest even a casual site visitor.
Parallax scrolling was used quite successfully by Nike. The company's original website was developed by designers Weiden and Kennedy. But this design was not preserved. The resource was gradually updated in accordance with modern trends. Activatedrinks.com is an example of a site whose design is reminiscent of the design used by Nike marketers from this period.
There shouldn't be too much dynamics
Do not forget that the design of the site is often key criterion, which guides the visitor. A poorly executed resource usually leaves the user with the impression that the owner company is not serious. But a website with various kinds of attractive design elements indicates the desire of the organization’s owners to interest visitors.
Here it is worth remembering about parallax. This is a wonderful tool. But even they shouldn’t get too carried away. Because the page on which there is a large number of various kinds of moving elements, quite difficult to understand. It is best to make the design moderately stylish and understandable.
Individual elements that require highlighting should be dynamic. There may also be a drawing that is created using layers moving relative to one another. Do not forget that a custom website is designed primarily for visitors. It should not be a masterpiece of a webmaster who has invested all his knowledge. After all, such an approach will only complicate perception.
How to create a movement on the site
How to make parallax? This question interests many website creators. It is not necessary to know the intricacies of writing tags. It is very convenient to use special resources on the Internet. From the large number of available proposals, the following assistants can be distinguished:
- Plax is a program that is quite easy to use. It tends to give the page movement by moving the mouse.
- jQuery Parallax Image Slider - jQuery plugin used to create image sliders.
- Jquery Image Parallax - suitable for designing transparent pictures. Through his use of PNG, GIFs gain depth while being brought to life by movement.
- Curtain.js is used to create a page equipped with fixed panels. In this case, the effect of opening the curtains is observed.
- Scrolling Parallax: A jQuery Plugin is to create a parallax effect when scrolling the mouse wheel.
Some more useful plugins
As you know, information has the greatest value. And the greater the number of ways to achieve what you want is known, the closer the probability of obtaining the right result. Useful plugins used to create dynamics:
- jQuery Scroll Path - used to place objects on a specified path.
- Scrollorama is a jQuery plugin. It is used as a tool for attractive design of the material. Thanks to convenient scrolling, it allows you to “revive” the text on the page.
- Scrolldeck - jQuery plugin. It is an excellent solution used as a presentation for websites designed as one page.
- jParallax represents the movement of layers depending on the movement of the mouse pointer.
- Stellar.js is a plugin with which any element is designed with the addition of a parallax scrolling effect.
Parallax with cursor snapping
This parallax looks quite impressive. Objects on a site page that seem motionless at first glance move when approached. It seems to come to life and follow the element being moved.
First you should stop at the drawing. The required image is placed in a frame, and its edges must be hidden. The method is very simple, and the resulting drawing looks quite attractive.
The parallax effect for a website is a wonderful design method. Its use indicates that due care was given to the creation of the resource. Therefore, it is worth paying attention to the services offered or information to read. Such sites look more advantageous against the background of identical, but simply designed resources.