Sight word three

Practice the Sight Word: three Game - ELA Games

Practice the Sight Word: three Game - ELA Games - SplashLearn

Home > Games > ELA Games > Practice the Sight Word: three Game

Put your language skills to the test by learning to practice the sight word: three.

Play game

Assign to class

SUBJECTS & TOPICS

Know more about Practice the Sight Word: three Game

Sure that your child knows the sight word three well? Play this exciting game that runs in a timed fashion to test their knowledge of the word three.

Explore Amazing Games on All Sight Words

View all 975 Games

Reading
Learn the Sight Word: I Game
Help your child practice english by learning the sight word: I.

Pre-K
K
VIEW DETAILS
Reading
Sound of the Sight Word: I Game
Practice the sound of the sight word: I.
Pre-K
K
VIEW DETAILS
Reading
Practice the Sight Word: I Game
Polish your language skills by practicing the sight word: I.
Pre-K
K
VIEW DETAILS
Reading
Learn the Sight Word: a Game
Help your child practice english by learning the sight word: a.
Pre-K
K
VIEW DETAILS
Reading
Sound of the Sight Word: a Game
Practice the sound of the sight word: a.
Pre-K
K
VIEW DETAILS
Reading
Practice the Sight Word: a Game
Polish your language skills by practicing the sight word: a.
Pre-K
K
VIEW DETAILS
Reading
Learn the Sight Word: the Game
Help your child practice english by learning the sight word: the.
Pre-K
K
VIEW DETAILS
Reading
Sound of the Sight Word: the Game
Introduce your child to the sound of the sight word: the.
Pre-K
K
VIEW DETAILS
Reading
Practice the Sight Word: the Game

Polish your language skills by practicing the sight word: the.
Pre-K
K
VIEW DETAILS
Reading
Learn the Sight Word: and Game
Help your child practice english by learning the sight word: and.
Pre-K
K
VIEW DETAILS
Reading
Sound of the Sight Word: and Game
Introduce your child to the sound of the sight word: and.
Pre-K
K
VIEW DETAILS
Reading
Practice the Sight Word: and Game
Polish your language skills by practicing the sight word: and.
Pre-K
K
VIEW DETAILS
Reading
Learn the Sight Word: it Game
Help your child practice english by learning the sight word: it.
Pre-K
K
VIEW DETAILS
Reading
Sound of the Sight Word: it Game
Introduce your child to the sound of the sight word: it.
Pre-K
K
VIEW DETAILS
Reading
Practice the Sight Word: it Game
Polish your language skills by practicing the sight word: it.
Pre-K
K
VIEW DETAILS

Discover Fun Games on Sight Words

View all 975 Games

Reading
Can You Find the Uppercase Letter A? Game
To play this game, find the uppercase letter A.
Pre-K
K
VIEW DETAILS
Reading
Can You Find the Lowercase Letter a? Game
To play this game, find the lowercase letter a.
Pre-K
K
VIEW DETAILS
Reading
Learn the Letters: Big A Game
Put your language skills to the test by learning the letter: Big A.
VIEW DETAILS
Reading
Practice the Letters: Big A Game
Kids must practice the letter: Big A.
VIEW DETAILS
Reading
Learn the Letters: Small a Game
Put your language skills to the test by learning the letter: Small a.
VIEW DETAILS
Reading
Practice the Letters: Small a Game
Put your language skills to the test by practicing the letter: Small a.
VIEW DETAILS
Reading
Match Big and Small A Game
Put your language skills to the test by learning to match big and small A.
Pre-K
K
VIEW DETAILS
Reading
Find the Letters A, B, C & D Game
Put your language skills to the test by finding the letters A, B, C & D.
Pre-K
K
VIEW DETAILS
Reading
Can You Find the Uppercase Letter B? Game
To play this game, find the uppercase letter B.
Pre-K
K
VIEW DETAILS
Reading
Can You Find the Lowercase Letter b? Game
To play this game, find the lowercase letter b.
Pre-K
K
VIEW DETAILS
Reading
Learn the Letters: Big B Game
Put your language skills to the test by learning the letter: Big B.
VIEW DETAILS
Reading
Practice the Letters: Big B Game
Kids must practice the letter: Big B.
VIEW DETAILS
Reading
Learn the Letters: Small b Game
Put your language skills to the test by learning the letter: Small b.
VIEW DETAILS
Reading
Practice the Letters: Small b Game
Put your language skills to the test by practicing the letter: Small b.
VIEW DETAILS
Reading
Match Big and Small B Game
Put your language skills to the test by learning to match big and small B.
Pre-K
K
VIEW DETAILS

Find Engaging Games on Reading

View all 2,209 Games

Reading
Can You Find the Uppercase Letter C? Game
To play this game, find the uppercase letter C.
Pre-K
K
VIEW DETAILS
Reading
Can You Find the Lowercase Letter c? Game
To play this game, find the lowercase letter c.
Pre-K
K
VIEW DETAILS
Reading
Learn the Letters: Big C Game
Put your language skills to the test by learning the letter: Big C.
VIEW DETAILS
Reading
Practice the Letters: Big C Game
Kids must practice the letter: Big C.
VIEW DETAILS
Reading
Learn the Letters: Small c Game
Put your language skills to the test by learning the letter: Small c.
VIEW DETAILS
Reading
Practice the Letters: Small c Game
Put your language skills to the test by practicing the letter: Small c.
VIEW DETAILS
Reading
Match Big and Small C Game
Put your language skills to the test by learning to match big and small C.
Pre-K
K
VIEW DETAILS
Reading
Can You Find the Uppercase Letter D? Game
To play this game, find the uppercase letter D.
Pre-K
K
VIEW DETAILS
Reading
Can You Find the Lowercase Letter d? Game
To play this game, find the lowercase letter d.
Pre-K
K
VIEW DETAILS
Reading
Learn the Letters: Big D Game
Put your language skills to the test by learning the letter: Big D.
VIEW DETAILS
Reading
Practice the Letters: Big D Game
Kids must practice the letter: Big D.
VIEW DETAILS
Reading
Learn the Letters: Small d Game
Put your language skills to the test by learning the letter: Small d.
VIEW DETAILS
Reading
Practice the Letters: Small d Game
Put your language skills to the test by practicing the letter: Small d.
VIEW DETAILS
Reading
Match Big and Small D Game
Put your language skills to the test by learning to match big and small D.
Pre-K
K
VIEW DETAILS
Reading
Can You Find the Uppercase Letter E? Game
To play this game, find the uppercase letter E.
Pre-K
K
VIEW DETAILS

Related Worksheets

View all 1,063 Worksheets

Reading
Find Letter A Worksheet
Enhance your linguistic skills by finding the letter 'A' with this worksheet.
VIEW DETAILS
Reading
Spot Letter a Worksheet
This ELA worksheet will fill your child with zest as they spot the letter 'a'.
VIEW DETAILS
Reading
Where's Letter B Worksheet
Enhance your linguistic skills by finding the letter 'B' in this worksheet.
VIEW DETAILS
Reading
Learn About Letter b Worksheet
In this worksheet, learners will get to learn about the letter 'b'.
VIEW DETAILS
Reading
Look for Letter C Worksheet
Add elements of fun to your ELA practice by looking for Letter C.
VIEW DETAILS
Reading
Color Letter c Worksheet
Enhance your linguistic skills by coloring the letter 'c' with this worksheet.
VIEW DETAILS
Reading
Color Letter D Worksheet
Enhance your linguistic skills by coloring the letter 'D' with this worksheet.
VIEW DETAILS
Reading
Look for Letter d Worksheet
Become more versatile in English by looking for letter 'd'.
VIEW DETAILS
Reading
Circle Letter E Worksheet
Learners must circle the letter 'E' to improve their ELA skills.
VIEW DETAILS
Reading
Where's Letter e Worksheet
Enhance your linguistic skills by finding the letter 'E' in this worksheet.
VIEW DETAILS
Reading
Look for Letter F Worksheet
Learners must look for the letter 'F' to improve their ELA skills.
VIEW DETAILS
Reading
Circle Letter f Worksheet
Learners must circle the letter 'f' to improve their ELA skills.
VIEW DETAILS
Reading
Where's Letter G Worksheet
Enhance your linguistic skills by finding the letter 'G' in this worksheet.
VIEW DETAILS
Reading
Find Letter g Worksheet
Enhance your linguistic skills by finding the letter 'g' with this worksheet.
VIEW DETAILS
Reading
Learn About Letter H Worksheet
Reinforce ELA concepts by learning about the letter 'H'.
VIEW DETAILS

Your one stop solution for all grade learning needs.

Give your child the passion and confidence to learn anything on their own fearlessly

Parents, Sign Up for Free

Teachers, Use for Free

4,413+

4,567+

Dolch Sight Words List | Sight Words: Teach Your Child to Read

All the Dolch sight word lists, divided by grade, also available as printable PDFs.

Five techniques for teaching Dolch sight words. Learn proven ways to introduce words, reinforce learning, and correct mistakes.

Print a set of Dolch sight word flash cards, or use our generator to create your own custom cards.

Print cards and game boards for 18 Dolch sight word games. A fun way to reinforce sight words lessons!

The Dolch Sight Words list is the most commonly used set of sight words. Educator Dr. Edward William Dolch developed the list in the 1930s-40s by studying the most frequently occurring words in children’s books of that era. The list contains 220 “service words” plus 95 high-frequency nouns. These words comprise 80% of the words you would find in a typical children’s book and 50% of the words found in writing for adults. Once a child knows this list of words, it makes reading much easier, because the child can then focus his or her attention on the remaining words.

The Dolch words are commonly divided into groups by grade level, ranging from pre-kindergarten to third grade, with a separate list of nouns. There are a total of 315 Dolch Sight Words.

Pre-K Dolch Sight Words
(40 words)
a, and, away, big, blue, can, come, down, find, for, funny, go, help, here, I, in, is, it, jump, little, look, make, me, my, not, one, play, red, run, said, see, the, three, to, two, up, we, where, yellow, you
Kindergarten Dolch Sight Words
(52 words)
all, am, are, at, ate, be, black, brown, but, came, did, do, eat, four, get, good, have, he, into, like, must, new, no, now, on, our, out, please, pretty, ran, ride, saw, say, she, so, soon, that, there, they, this, too, under, want, was, well, went, what, white, who, will, with, yes
First Grade Dolch Sight Words
(41 words)
after, again, an, any, as, ask, by, could, every, fly, from, give, going, had, has, her, him, his, how, just, know, let, live, may, of, old, once, open, over, put, round, some, stop, take, thank, them, then, think, walk, were, when
Second Grade Dolch Sight Words
(46 words)
always, around, because, been, before, best, both, buy, call, cold, does, don’t, fast, first, five, found, gave, goes, green, its, made, many, off, or, pull, read, right, sing, sit, sleep, tell, their, these, those, upon, us, use, very, wash, which, why, wish, work, would, write, your
Third Grade Dolch Sight Words
(41 words)
about, better, bring, carry, clean, cut, done, draw, drink, eight, fall, far, full, got, grow, hold, hot, hurt, if, keep, kind, laugh, light, long, much, myself, never, only, own, pick, seven, shall, show, six, small, start, ten, today, together, try, warm
Noun Dolch Sight Words
(95 words)
apple, baby, back, ball, bear, bed, bell, bird, birthday, boat, box, boy, bread, brother, cake, car, cat, chair, chicken, children, Christmas, coat, corn, cow, day, dog, doll, door, duck, egg, eye, farm, farmer, father, feet, fire, fish, floor, flower, game, garden, girl, goodbye, grass, ground, hand, head, hill, home, horse, house, kitty, leg, letter, man, men, milk, money, morning, mother, name, nest, night, paper, party, picture, pig, rabbit, rain, ring, robin, Santa Claus, school, seed, sheep, shoe, sister, snow, song, squirrel, stick, street, sun, table, thing, time, top, toy, tree, watch, water, way, wind, window, wood
All Dolch Sight Words by group
All Dolch Sight Words in alphabetical order

Mechanical sights.

Types and features

Recently, people have often been arguing about the types of sights - which is better - a slot or an aperture, a large hole or a small one. And in the course of the dispute, it becomes clear that the opponents know the subject of discussion only by hearsay, or, at best, after a cursory acquaintance. The desire to clarify and systematically understand the issue was the motive for writing this text.
So, as a basis, I took the sights that are put on military weapons and its derivatives, I do not consider hunting models consciously. nine0004

Mechanical sights

Mechanical sights on weapons are structural elements, the combination of which forms a line of sight. These can be flat bars, slots and holes of various shapes as a rear sight (sight), as well as holes, threads, rods, needles, barrels as a front sight (front sight).
Two main types of sights for hand-held long-barreled small arms - open and closed (aperture or ring). nine0003 According to GOST 28653-2018 they should be called open and diopter, respectively.
An open sight is a rear sight with a rectangular/square/U-shaped slot, etc. (for example, a classic AK rear sight).

Diopter sight - rear sight with a round, square or diamond-shaped hole (sight M4 or AK12).

The results of shooting depend on the correct choice of type and the correct configuration of sighting devices.
I will try to state the advantages and disadvantages of these types of sights, based on my personal experience and, in part, compiled materials from the network, also passed through the filter of my experience. The experience at the moment is approximately the same - more than 60 thousand shots from weapons with an open sight and more than 85 thousand with a closed one. nine0003 In order not to make permanent references to terms and definitions further in the text, I will list them in advance and describe them.

Terms and definitions

Focus of an optical system is the point at which initially parallel beams intersect ("focus") after passing through the collecting system. In our case, if we see an object sharply, then it is at the distance at which our eye is focused, or "the object is in focus" . nine0003

Aperture diaphragm is a barrier or frame of one of the lenses, which restricts the beams of rays emerging from the points of the object located on the optical axis and passing through the optical system. In our case, this is a frame or an object with a hole, which is a closed rear sight.

Aperture is a value that characterizes the light transmission of an optical system. In our context, how much darker is the image when viewed through the scope and without it. Low aperture leads to a darkening of the field of view in the sight. Applies to closed sights only. nine0004

Parallax - change in the apparent position of the object relative to the distant background, depending on the position of the observer. For us, this will sound like the influence of the position of the front sight in the sight on the accuracy of the hit. The higher the parallax, the more the hits will shift with a slight movement of the front sight in the rear sight.

Diffraction - the phenomenon of light deflection from the rectilinear direction of propagation when passing near obstacles. This means that when diffraction occurs, the target pattern or part of it begins to blur. nine0003

Aberration - an error in the optical system, a violation of the focusing of light beams on the spherical surfaces of the lenses, caused by different degrees of refraction. In our case, blurring of observed objects, especially those that are out of focus. The less aberration, the clearer the picture.

Light irradiation - an apparent increase in the size of light figures on a black background. This means that a light figure on a black background seems more dark, with the same actual size. This effect is especially noticeable when there is a light background on one side of the front sight and the target, and a dark background on the other. nine0004

Depth of Field or Depth of Field (DOF) - the distance along the optical axis in space, within which objects are displayed subjectively sharp. The more depth of field - the more space is in focus, that is, it is seen sharply by us. You can increase the depth of field by aperture (reducing the aperture diameter) of the optical system, this will suppress the effect of aberration and make objects sharper. The simplest example. Extend your hand in front of you with your finger extended - this will be about half a meter from the eye. Focus on your finger. Everything that is further than it - one meter from the eye and beyond, will be blurry. But if you look at your finger through a 2mm aperture (for example, the aperture of a ring sight), objects behind it become much sharper. This effect works when the diaphragm diameter is smaller than the pupil diameter. The farther away the object in focus is, the greater the depth of field. nine0004

Accommodation - the ability of the eye to change the focal length due to muscle contraction and relaxation. That is, the ability to transfer focus to objects located at different distances.

Types of sights and their features

Open

The rear sight is at some distance from the eye so that the shape of the slot and the upper edge are as clear as possible, provided that the focus is NOT on the rear sight. On this type of sight, the correct sighting line is the alignment of the top plane of the front sight with the plane of the rear sight, and the location of the front sight in the slot so that the gaps between the front sight and the sides of the slot are the same. At this point, one of the worst enemies of correct aiming is light irradiation. Uneven illumination of parts of the target, as well as background elements that differ in brightness and color behind the target, negatively affect the correct perception of gaps on the sides of the front sight. nine0004

This type of rear sight is not closed, therefore it does not have the properties to cut off part of the rays, and therefore does not affect the brightness of the perceived image or depth of field. The width of the rear sight slot affects the size between the side wall of the slot and the side of the front sight, allowing for more accurate positioning or faster catching of the fly in the slot. The wider the slot, the easier it is to find the fly faster, but the higher the error in its positioning. Already a slot - it is more difficult to quickly find the fly, but positioning is more accurate. By the way, the AK103 front sight, pressed close to one of the walls of the rear sight, leads the group to the side by 12-15 centimeters at 50 meters, and the front sight, pressed to the “bottom” of the slot, lowers the group by more than 50 centimeters at the same distance. Plus, diffraction comes into play, which, with an excessively narrow slot, begins to make it poorly distinguishable, since the slot merges. The minimum size of the slot, when it is still clearly visible, is called optimal. It depends on many factors, the main of which in our case is the individual characteristics of the shooter's vision. nine0004

The next nuance of working with this type of sight, arising from the peculiarities or, rather, shortcomings of the structure of the optical system of the human eye, is the inability to simultaneously sharply observe objects at different distances. We simultaneously see clearly either the rear sight, or the front sight, or the target. Let me remind you that in classic bullet shooting, the focus is on the front sight, and the rear sight and the target are blurry. Everything is clear with everything, but what to do with the target if these are not ideal shooting range conditions, when the lighting is the same, the target is static and contrasting? Suddenly it merges with the background, moves, or is unevenly lit? Here you have to constantly shift focus (accommodate) from the front sight to the target, or sacrifice the sharpness of the front sight too. nine0004

The advantage of this type of sight is that there are no objects above the front sight that block the view. But there is also a drawback - the rear sight with the front sight hides everything that is under the target below the level of the top of the front sight. When transferring a weapon from target to target, the view is the same for both eyes, in the case of transfer to the side of the driven eye, the new target first enters its field of view.

The correct position of the weapon - the absence of a blockage - is subjectively assessed by the horizon of the upper face of the rear sight.

Closed ring (with small ring diameter - less than 3 mm)

The rear sight is at a minimum distance from the eye so that the width of the space observed through the hole is maximum, and the inherent capabilities of such an optical system are realized - increasing the depth of field. On this type of sight, the correct sighting line is the alignment of the upper plane of the front sight with the center of the rear sight ring, and the location of the front sight in the ring so that the gaps between the front sight and the walls of the ring are the same. Thanks to the intuitive sense of symmetry of the eye, the front sight is placed in the center of the visible zone without any additional effort. Different illumination of the target parts, different brightness and background colors have little effect on the correct perception of the aiming image, since the visible area is quite large compared to an open sight. nine0003

This type of rear sight is closed, therefore it has the properties to cut off part of the rays of transmitted light, which means it affects the brightness of the perceived image. Thus, a small diameter aperture does not allow the use of this type of sight at dusk and at night. Rear sight aperture diameter affects speed and accuracy. Larger aperture diameter - faster target image formation, but lower accuracy. Smaller diameter - slower formation of the sighting image, but the accuracy is higher. Due to the effect of parallax suppression on this type of sight, the error when aiming is negligible. What does this mean in practice? As long as the diaphragm diameter is smaller than the pupil diameter, even the imperfect location of the front sight in the center of the ring almost does not lead to the STP - the parallax effect is almost completely suppressed. It begins to be observed only when the axis of the eye is shifted further than the edge of the diaphragm - but even in this case, the withdrawal of the STP is not catastrophic. nine0004

For comparison, the AK12 front sight, pressed close to the wall of the standard ring, leads the group in the corresponding direction by 6-8 centimeters at 50 meters, regardless of direction. I note that increasing the pupil diameter while maintaining the aperture diameter of the sight increases parallax suppression even more. That is, on an enlarged pupil, you can shift the sight even more, but this will not lead to additional withdrawal of the STP. It is this effect that is used on rifles for biathlon and bullet shooting - a large “pancake” is installed on the rear sight, which reduces the illumination of the eye, due to which the pupil expands. By the way, in terms of parallax suppression, diopter sights are better than some collimator and holographic sights. nine0004

To put it simply, in a small diameter ring sight, there is no need to focus on the ideal location of the front sight in the ring. It is better to spend this time on the exact location of the front sight on the target.

The next feature is aperture. The smaller the ring, the darker the image. The difference in the brightness of the picture through the sight and without it becomes indistinguishable when the pupil diameter is equal to or less than the diameter of the aperture of the sight.

The third is diffraction, which, with a very small ring diameter, begins to “blur” the picture. The periphery is especially “blurred” due to the phenomenon of aberration. The size of the diaphragm, when the phenomenon of diffraction is not yet so obvious, is called optimal. It depends on many factors, the main of which in our case is the individual characteristics of the shooter's vision. nine0004

Then there are the advantages of working with this type of sight, arising from the features of optical systems. When diaphragming (that is, reducing the diameter of the ring), the depth of field increases, which means that it becomes possible to simultaneously subjectively sharply observe objects at different distances.

For example. With a diaphragm diameter of 2.0 mm, taking into account my far from ideal vision, observing a target at a distance of 200 meters, I quite clearly see the space at + -100 meters along the depth of the aiming line. With this type of sight, it is easier to deviate from the basic principles of aiming bullet fire if the shooting is not carried out in ideal shooting range conditions. I focus at a distance a little further than the front sight, about 0.5-1.5 meters. And the space visible in the sight has increased sharpness. By cutting off part of the beams, aberration in the eye is suppressed, and the image observed in the sight becomes sharper than outside the sight. This quality is especially valuable when it is necessary to control several targets, or work with non-contrasting targets. An increase in depth of field reduces the amount of accommodation, which less tires the muscles of the eyes. nine0004

At the same time, it is necessary to understand exactly that an increase in the length of the aiming line, which occurs when using a closed sight, with a constant position of the front sight, is a necessary condition for increasing the depth of field. The shorter the aiming line, the less depth of field. The farther the sight ring is from the eye, the less depth of field. The optimal distance is 4-8 cm - a common mistake is to put the ring rear sight at a distance from the eye. This, by the way, is one of the reasons why I always prefer to shoot with the shortest stock length possible for the situation. nine0003

A slight disadvantage of this type of sight is that above the front sight there is a part of the rear sight ring that obscures the view. But, given the size of the zone visible in the ring, this problem is rather far-fetched. But there is an advantage, in contrast to the open one - there is a visible space below the top of the front sight.

One of the main drawbacks and a trap for inexperienced shooters is that on sights with a small aperture diameter, when the weapon is quickly transferred from target to target at close range, the view for the leading and driven eyes is different. At the same time, the brain unconsciously begins to switch visual channels from which it receives information. And the leading eye becomes the driven one, which leads to an incorrect assessment of the aiming picture and incorrect aiming of the weapon. But I repeat, this effect is typical only for small diaphragm diameters - 2.2 mm or less, in conditions of high-speed transfer at close range up to 50 meters, only for small targets, and the lack of proper skill. nine0004

And another typical mistake for beginners is an attempt to aim not with a fly, but with protective "horns", i.e. the shooter starts aligning the ring or "forks" of the front sight guard in the ring of the rear sight - this is an incorrect technique. This method can be used in ghost-ring scopes and when shooting at very close ranges. Getting used to it is quite easy - you need to remember that the protection of the front sight is just the protection of the front sight, and not part of the aiming system.

The correct position of the weapon - the absence of a blockage - is evaluated by the vertical front sight. nine0004

Closed annular Ghost-ring (with large ring diameter - 3-5 mm)

The rear sight is at a minimum distance from the eye in order to realize the effect of the Ghost-ring (Ghost-ring) - a thin circle shadow in front of the leading eye, on which the front sight is centered. On this type of sight, the correct aiming picture is focus on the target and a defocused front sight, which is intuitively centered in the ring. Thanks to the sense of symmetry of the eye, the front sight is placed in the center of the visible zone without any additional effort. Uneven illumination of parts of the target, as well as elements of the background behind the target that differ in brightness and color, have little effect on correct perception, since the visible zone is very large compared to an open sight. nine0099

The advantages of working with this type of sight include the speed of forming an aiming image, the speed of transfer and the convenience of working on moving targets. Given the short range operation, there is no need to keep focus on or close to the front sight - you can fully control and keep the target in focus.

This type of rear sight is closed, but due to the size of the hole it does not affect the brightness of the perceived image during daylight hours - the pupil of the eye will be exactly smaller than the aperture diameter. But, this also reduces the effect of parallax suppression - and the errors will become larger, and there is no effect of increasing the depth of field. For comparison, a front sight pressed close to the wall of a ring with a diameter of 4.5 mm leads the group in the corresponding direction by 20 centimeters at 50 meters, regardless of direction. Thus, it becomes extremely problematic to conduct guaranteed accurate fire at a target the size of a target 4 further than 100 meters. But the size of the hole allows the use of this type of sight at dusk and even on a moonlit night, and it is in such conditions that the pupil of the eye expands to 8 mm, which means it becomes larger than the aperture diameter - and the depth of field increases again and parallax is suppressed. Of course, provided that the target is visible. nine0004

Another disadvantage of this type of sight is that it is difficult to use it on brightly lit targets with a front sight of standard thickness, it begins to get lost due to illumination - if this type of sight is the main one, it is definitely worth trying to put a thicker front sight.

The correctness of the position of the weapon - the absence of blockage - is evaluated by the vertical of the front sight, but at short distances this does not have any significant effect on accuracy.

nine0006 Fire process

If we simplify the process of producing an aimed shot with the help of mechanical sights as much as possible, then we can describe it in the following steps:

1. Bringing the weapon to the aiming line

2. Alignment of the aiming line with the visual axis of the eye

3. Aligning the aiming image with the required aiming point (TA)

4. Processing the descent with the control of maintaining the correctness of the aiming image and its alignment with the dot on the target before the shot is fired. nine0004

5. Hit control / aiming image alignment for re-shot / weapon transfer with target search.

Now let's go through the types of sights with a description of the process of working with them in this sequence of actions.

Open

Since the rear sight is at some distance from the eye, especially if lateral corrections are introduced by moving the rear sight, it may take some time after step 1 to find the correct position of the head for the front sight to fall into the slot (step 2 ). After that, the weapon is aimed at the target by aligning the aiming image with the required aiming point on the target (step 3 ). At this stage, the correct aiming is greatly influenced by the glare and illumination of the sides of the front sight and the upper edge of the rear sight and front sight, as well as the background, its uniformity and the contrast of the target against the background - light irradiation works against us. During the 4 stage, it is necessary to constantly monitor not only the position of the front sight on the target, but also the position of the front sight in the rear sight slot. Further, if it is necessary to control the hit of stage 5 you need to focus on the target, control the hit, and decide on the transfer of fire, or again focus on the front sight and finish off.

Closed - both types

Since the rear sight is as close as possible to the eye, at the stage 1 the eye, with proper skill, instantly finds the rear sight hole itself. And during the second stage, he also intuitively positions the fly in the center of the ring. At the same time, it makes little sense to control its position in order to ideally position itself in the ring, if we are not talking about sniper shooting. During stage 3 The focus is on aiming the front sight at the target, there is no need to additionally control the position of the rear sight. During step 4 all control over the position of the front sight in the right place on the target, and not the rear sight and the target. If after step 4 it becomes necessary to control the hit (step 5 ), then the target is usually in the focus zone due to the increase in depth of field - and there is no need for additional accommodation.

It is logical that a high level of aiming skill allows minimizing the difference in time between the formation of an aiming image and the search for a target, as well as the transfer of fire. But the skill cannot compensate for the increase in depth of field, just as it cannot allow you to see the front sight in an open rear sight in deep twilight. nine0004

Output

Open sight

Advantages:

simplicity of design and manufacturing technology
the ability to install on almost any weapon in the center of the structure
no master-slave eye switching effect
no effect on the illumination of the aiming image

Disadvantages: nine0004

parallax
the need for constant emphasis on front sight control in the rear sight
phenomenon of light irradiation
the need to refocus from the front sight to the target to control the hit

Closed sight

Advantages:

parallax suppression
no need for perfect alignment of the front sight in the rear sight ring nine0004
increase in depth of field
almost complete absence of the phenomenon of light irradiation
the ability to detect small details (reconnaissance) in the sighting image by increasing sharpness and depth of field

Disadvantages:

complexity of design and manufacturing technology
installation as close to the eye as possible is not possible on every weapon
nine0265
master-slave eye switching effect at small ring diameters and short distances
influence on the illumination of the aiming image - small aperture at a small aperture

There are misconceptions that ring sights are more prone to failure due to dirt/snow/water ingress. Properly selected ring design and hole diameter have the same chance of clogging as the slot of an open rear sight. And here there are two options. Or this blockage is easy enough to remove by blowing the sight / shaking the weapon. Or the same clogging happened with a front sight located in a protective rim, which is much more difficult to clean without improvised means than any rear sight. nine0004

There is no single correct mechanical sight. All have their advantages and disadvantages. But we can definitely say that the best scope is the one that you know how to use.

Georgy Gubich aka Zhora Nefteskvazhinsky
Special thanks to D*** and R***** for edits

SIGHT CONTROL OF THE FREQUENCY SPECTRUM OF ELASTIC PLATES WITH A FINITE NUMBER OF MASS DEGREES OF FREEDOM BY APPLICATION OF ADDITIONAL CONNECTIONS

##plugins.themes.bootstrap3.article.sidebar##

PDF (English)

Posted: Jun 24, 2021

DOI: https://doi. org/10.22337/2587-9618-2021-17-2-76-82

Key words:

frequency of natural oscillations, form of natural oscillations, aiming connection, additional connection, stiffness coefficients

##plugins.themes.bootstrap3.article.main##

Leonid Lyakhovich

Tomsk State University of Architecture and Civil Engineering, Tomsk, RUSSIA

Pavel Akimov

National Research Moscow State University of Civil Engineering, Moscow, RUSSIA

Abstract

To date, for some elastic systems with a finite number of degrees of freedom of masses, in which the directions of movement of the masses are parallel and lie in the same plane, methods have been developed for creating additional bonds that purposefully change the frequency spectrum of natural oscillations. In particular, for rods, a theory and algorithm for the formation of targeted additional bonds have been developed, the introduction of each of which does not change any of the modes of natural vibrations, but only increases the value of only one frequency without changing the values of the other frequencies. This article shows that the method of forming a matrix of additional stiffness coefficients that characterize such an impact relationship in the problem of natural vibrations of rods can also be applied to solve a similar problem for elastic systems with a finite number of degrees of freedom, in which the directions of mass movement are parallel, but not lie in the same plane. In particular, such systems include plates. However, the algorithms for the formation of targeted additional bonds developed for rods based on the properties of rope polygons cannot be used in a similar problem for plates without significant changes. The method of formation of calculation schemes of connections that purposefully change the frequency spectrum of natural vibrations of elastic plates with a finite number of degrees of freedom of masses will be considered in the next work. nine0004

Downloads

Download data is not yet available.

##plugins.themes.bootstrap3.article.details##

How to cite

Lyakhovich L. , & Akimov P. (2021). SIGHT REGULATION OF THE FREQUENCY SPECTRUM OF EFFICIENT VIBRATIONS OF ELASTIC PLATES WITH A FINITE NUMBER OF MASS DEGREES OF FREEDOM BY IMPLICATION OF ADDITIONAL CONNECTIONS. International Journal for Computational Civil and Structural Engineering , 17 (2), 76–82. https://doi.org/10.22337/2587-9618-2021-17-2-76-82

Section

Articles

This work is licensed under the Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.

Most read articles by this author(s)

Pavel Akimov, Alexander Belostotsky, Oleg Kabentsev, Vladimir Sidorov, Alexander Tusnin, ABOUT THE NATIONAL COMPUTING COMPLEX FOR THE CONSTRUCTION INDUSTRY , International Journal for Computational Civil and Structural Engineering: Volume 18 No. 1 (2022): International Journal for Computational Civil and Structural Engineering nine0265
Marina Mozgaleva, Pavel Akimov, Taimuraz Kaitukov, WAVELET-IMPLEMENTATIONS OF COMPUTATIONAL METHODS FOR CALCULATION OF BEAM STRUCTURES USING DAUCHEZI SCALING FUNCTIONS , International Journal for Computational Civil and Structural Engineering: Volume 15 No. 2 (2019): International Journal for Computational Civil and Structural Engineering
Marina Mozgaleva, Pavel Akimov, Taimuraz Kaitukov, WAVELET-IMPLEMENTATION OF THE DISCRETE-CONTINUAL FINITE ELEMENT METHOD FOR THE CALCULATION OF PLATES USING DOBECHE SCALE FUNCTIONS , International Journal for Computational Civil and Structural Engineering: Volume 15 No. 3 (2019): International Journal for Computational Civil and Structural Engineering

Pavel Akimov, Marina Mozgaleva, Taimuraz Kaitukov, NUMERICAL SOLUTION OF THE PROBLEM OF TRANSVERSAL BENDING OF A BEAMS BASED ON THE WAVELET IMPLEMENTATION OF THE FINITE ELEMENT METHOD USING B-SPLINES , International Journal for Computational Civil and Structural Engineering: Volume 16 No. 3 (2020): International Journal for Computational Civil and Structural Engineering nine0265
Marina Mozgaleva, Pavel Akimov, Mojtaba Aslami, NUMERICAL SOLUTION OF THE BOUNDARY PROBLEM FOR THE POISSON EQUATION ON THE BASIS OF THE DISCRETE CONTINUAL FINITE ELEMENT METHOD WITH THE USE OF DAOBCHES SCALING FUNCTIONS , International Journal for Computational Civil and Structural Engineering: Volume 17 No. 4 (2021): International Journal for Computational Civil and Structural Engineering nine0265
Leonid Lyakhovich, Pavel Akimov, Nikita Meshcheulov, FORMATION OF CALCULATION SCHEMES OF ADDITIONAL CONNECTIONS, SPECIFICALLY REGULATING THE FREQUENCY SPECTRUM OF ELASTIC SYSTEMS WITH A FINITE NUMBER OF MASS DEGREES OF FREEDOM, WHERE THE DIRECTIONS OF MOTION ARE PARALLEL BUT NOT LAYING IN THE SAME PLANE , International Journal for Computational Civil and Structural Engineering: Volume 18 No.
Learn more