How to tell if the picture has been PS

Let me share my experience with you. I'm not going to talk about the major digital change principles, and I'll elaborate on that from a pragmatic perspective. I divide the method of judging whether a picture is PS into four categories:

Facts cannot

Physical cannot

Photography cannot

Details cannot

　　Facts cannot

The fact cannot be based on the general experience of people can be determined that this is impossible.

It is divided into two categories:

1: The obvious facts cannot

2: The Facts of logic cannot

The obvious fact cannot be a picture that can be judged by a person's general experience, contrary to the obvious common sense, such as a person jumping 10 meters high.

The fact of logic does not mean that the picture itself is not a problem, but according to other conditions there will be logical contradictions, such as creeps June, the photos of ginkgo is yellow.

　Physical cannot

Physics cannot be divided into three categories:

Reflection cannot

Light and Shadow cannot

Color can not

Reflection does not mean that a scene, such as a lake, a glass surface, that should have been reflected, has not appeared. As shown in the following picture:

In response to this picture, it was said that the polarizer can remove the reflection, but this picture of the camera equipment is the iphone, his intention is that the iphone can also take good pictures, and then sucked into the popularity of the commercial propaganda.

Light and Shadow can not refer to the overall high-gloss and shadows, the obvious inconsistency of hue. As shown in this picture:

We intercept the above image of the Cloud section, and then use Google Image Search, you will find this picture:

The truth is a look at the cicada, right

The use of the Internet is also a good way to identify

Color can not

Color can not mean the whole picture of the tone obviously inconsistent, there is a clear degree of differentiation. Refer to the previous picture.

Photography cannot

Photography cannot be divided into four categories:

Focal length cannot

Shutter cannot

Depth of field cannot

Latitude cannot

The focal length can not be such as the South China Tiger incident, according to the focal length may judge him and the tiger distance very close, also the fact cannot.

The shutter can not refer to the same picture but there are two shutter time to form a scene, such as the main picture is a drop falling water droplets, the background is a long exposure to form the flow of traffic (it is mentioned that after the curtain synchronization, it is true that the rear curtain synchronization will form a slow shutter and fast shutter combination of the scene, but the rear curtain synchronization And the difference between the flash and natural light is more obvious, it is better to distinguish.

The depth of field does not refer to objects located in the same focal plane, but there is a clear and imaginary difference (with the exception of the moving axis lens, but considering the special type and popularity of the shift lens, it is not taken into account).

Latitude does not mainly refer to the photos taken by mobile phones but there is a very high latitude. (possibly HDR)

Details cannot

This is actually very simple, constantly enlarge the picture, see whether the edge of the picture is clear, the gradient is natural and so on

Here are a few specific photos to illustrate:

The details of this photograph are not in place, the edges are clearly left, the depth of field is too shallow, and the coke is unreal.

The cloud in the upper right corner of this photo is a long exposure to form, combined with its EXIF information, the shutter speed can not be so slow.

The obvious fact of this picture cannot.

This picture tonal collocation what is good, because there is no big picture, so look at the details is also good, but the boy's perspective relationship is not too true, the fact that the logic is not. Perspective relationship Unreal refers to the boy and his reflection, if the picture does not have a boy and his reflection, it is really a good picture of P.

This photo shutter speed is too fast, but there is a starry sky, belongs to the shutter can not, of course, the ability of students according to the city this time the sky should be the arrangement of the logic of the facts can not be judged.

Say more about this picture, the shutter speed of this picture is 1/200, it is difficult to shoot out of the sky. Personal guess this picture is taken during the day, and then PS into the appearance of the night, and then pull the picture plus the starry sky.

Why is it?

One is 1/200 of the shutter speed is difficult to make a night scene, the picture of the quality is still relatively high, of course, do not rule out high sensitivity and good imaging.

Second, if it is taken at night, there should be light, the whole picture should be a dot or a group of high-gloss, but the picture does not have such a scene.

I tried, this is a contrast chart, time haste, do not fine, one is to pull the picture is not good, two is not too much attention to the effect of light and shadow.

In the face of such a picture, we can look for the physical can not reflect the reflection can not, such as the left corner of the screen of this huge reflector, often found a lot of information, which is the P-map to pay attention to the details.

The gravity effect of the hair in this photo shows that it should have a brace.

According to the time of the photograph, the leaves should be all green, but all of them turn yellow.

For the last one, someone asked me why the last photo was a problem with the picture, not the time?

That's because the last one is my own color –-! Put the original:

For some of the time problems raised by friends, it is indeed worth noting that some time itself is wrong, so there is a lack of comparative value, but the personal habit of the camera time set accurate, so did not notice this.

Do you have any questions about this picture?

This picture I look at the first glance is not harmonious, but the specific where the problem can not be seen, there is only one item to judge.

A PS photo is the most difficult factor to unify the light and shadow, I decided to start from the light.

The high light portion of the cloud appears in the middle of the cloud, indicating that the light source is from the center-right side. And the shadow of the car on the road shows that the light comes from the left, and watch the shadow of the bus.

The light source is not unified, it may be modified.

To further prove, I used Google to search the image of the cloud, no gains. Because the color of the dark cloud information is not strong, plus this picture is also done in black and white processing, so it is not easy to find.

But don't lose heart, Baidu image search keywords dark clouds try

Sure enough, on the second page, I found the original!

Contrast, the same cloud!

Black and white photos are more difficult to judge the figure, because the physical can not be the color of this one of the basic loss of function, the other two performance is not obvious, it is more difficult to judge.

Of course such photographs can also be judged by the fact that logic does not. If you know which city this is, know whether the road is north-south or east to west or other direction, and then according to EXIF information to determine the direction of the sun, and then combined with the light source in the image to judge.

In fact, we can be based on the picture to reverse the direction of the road, specifically I will not elaborate.

Well, since someone asked me how to push back, I'll tell everyone.

This picture is a description of hkust, so it can be inferred that a University of science and Technology, and his registration information is in Tianjin, combined, should be Tianjin hkust.

According to EXIF information, this picture was taken on March 17, 2013 1:15 P.M., because it is close to Beijing, so there is no need to convert into a place, when the Sun direct to the southern hemisphere

Therefore, it can be inferred that the sun rises from the southeast, landing from the southwest, the figure of the bus shadow shows that the sun should be in the left side, because the shadow in the upper right, and at this time has been Tianjin Place 12 points, so it can be inferred that the road should be northwest-southeast direction.

Look at the angle of this picture again, it is overhead imagery. Personal speculation was taken on the overpass, and then combined with his description: the gate

Find the gate of Tianjin Hkust with an overpass:

Combined with the direction of the traffic flow in the picture and the directions of the traffic in the map, it can be inferred that it should be taken on the left side of the overpass.

Through this example, I would like to explain:

It's really hard to forge a flawless picture.

Let's talk about the effect of photography on the picture itself.

Polarizing Mirror: polarizing mirror in the elimination of reflective, flare and other harmful light source these aspects have a great effect, add a polarizer after the photos taken out and the human eye to see the photos are really very different, as shown:

But the polarizer is generally not selective scattering light, if the same is the reflection of the water, the house is reflected, and the cloud does not, this should be considered to be PS.

Black Card: Shake Black card can make the high light and low light department to get different degrees of exposure, so that the photo details richer, more harmonious color, the individual think the principle and HDR, it can change the exposure time of different parts, but will not change the path of light.

Filters: Change photo color by color filter, or by using a medium gray mirror to make silk-like water, or through other filters to achieve special effects, this is not a modified photo? In fact, photography and the real is not the same thing, the lens can see the water like silk, you can see the star track, you can see the frozen droplets, Can the human eye? Photography is a kind of artistic creation, so we do not have to be demanding that photography is something that the human eye can see.

Understand this truth, my personal point of view is: Through the early means to shoot out even if the sight of the unseen, also does not belong to the modified photo, because photography itself is a kind of creation. But through the late means to add to the actual content of the screen, I decided to modify the photo.

It is a controversial topic whether photography should be to restore reality or to look better. However, in all kinds of photography competitions, the changes in the real content of the photos are forbidden, that is, you are more beautiful for the photos, add a cloud, plus a person, is certainly forbidden, but the color of the picture is allowed, there is controversy.

One is that the change of color is far from easy to identify with the addition of content, even if modified, it may be difficult to be screened out.

The second is in the digital age, whether you are straight out of the JPG, or not straight out of raw, in fact, is the result of the software operation of the fuselage, and the process of the calculation is actually possible to change the color of the real scene, so we can naturally use to restore the truth as the reason, Modify the color or other non-substance of the photo to achieve what we call "real".

Thirdly, photography itself is a highly subjective creation. Why do the same scenes, some people shoot out like this, some people shoot out like that, and when you really reach there but found that is completely another kind of? I personally think there are several reasons:

One: The photograph is the product of a single directional view.

Why do some people look particularly beautiful in photos, but not in real life? That's because it's a static product, and the photographer can naturally find an angle that best shows her beauty, fixing it and forming a photograph. And in real life, everyone is three-dimensional, angle is 360°, relative to the photo of 1°, to 360° is more attractive than just 1 ° good-looking more difficult.

Two: The eye is not the lens.

Some people see the star track, feel good beautiful ah, but why I do not see it? Some people see the background of the virtual mess of flowers, feel good beautiful ah, why I do not see? Some people see silk-like water, feel good beautiful ah, but why I can not see it? Very simple, your eyes are not the lens, The lens can see what you can't see, that's all.

Three: The head behind the lens.

The same equipment, the same scene, the shot is completely different photos, this is why? Because photography is a creation, creation is the creation of people, the importance of people is self-evident.

IV: Post-technology.

Some people may have the original plot, that photography to be faithful to the original film. But our so-called original film is only the software calculated data, it is not the original film. For example, two cameras, the same scene shooting, two photos, two photos 99.99% of the color is consistent, and 0.01% is inconsistent, you can tell me, which is the original film? If you tell me that both are original pieces, then I'll tell you that there is only one real scene, When these two photos are different, it must not be the original film, if you just want to think that is the original film, then you only think that the camera is straight out of the original film, you are loyal to the camera straight out, rather than the real scene. In the film age, there are also darkroom techniques to modify photos, so, for later, do not have to be severely critical.

Comprehensive above, contrast adjustment, saturation adjustment, brightness adjustment, color temperature adjustment calculation is not a modified photo, I really can not give a conclusion. Let me ask you a question: Add a filter to the camera to improve the color temperature of the photos taken out, this is not a change of photos? Some people will say, of course, the photos you took and I saw the scene is not the same, and some people will retort: This is the film, Ah, I did not change on the computer. Or take a photo, add a warming filter in PS, to achieve the same effect as the previous period, this is not a change of photos? Some people say that, of course, because you are a late change, ah, but I may retort: I with the previous filter shot out of the effect of a touch, why the pre-addition is not a modification, later add even? Maybe he would argue with me: People's early change is through physical changes to achieve effect, you later change is through the change of data to achieve the effect, not the same. I will ask a question: Then if you do not know that he is a pre-added filter, I was late change it? At this time, perhaps no one has the courage to say that this picture is modified!

So, I'm talking about these methods are only for those who have changed the real content of the photo to be effective, for those who only changed the contrast, saturation, color temperature, brightness, really powerless, because of contrast, saturation, color temperature, brightness these things can also be modified through the filter, but no matter what filter to add, Can not be more than a cloudy day to shoot a sun come.

Finally, I would like to say, according to the above methods can determine whether a picture is PS, and not necessarily, as everyone knows, the world's PS master thousands, perhaps I speak of these for them is simply a primer should grasp the common sense, so, we do not make the picture "modified presumption", In the absence of full certainty, do not easily say no to other people's photos. For example, the first time I saw a heart-shaped aperture, I thought, "by the means of the iris, it must be P!" and then proved my ignorance and rudeness. There are also many photographers in the world, photography technology is also increasingly updated, many people can also through the previous method to achieve some unimaginable effect, we do not understand, not equal to their inability.

Go on.

This picture is to do relatively high-level pictures, do a reflection, key map meticulous, color with harmony, do a gradient processing, weakening the shape of the cloud, can reduce the search engine to find the probability, but still I caught the two point flaw:

One: Light and shadow relationship.

This is always a must kill technology ah, the picture of the clouds of light from below, and we observe the Pavilion shadow, biased to the left, indicating that the sun from the top right, the light source is inconsistent, the explanation may be p.

Two: logical judgment.

According to its registration information: Changsha, title: Yuelu Shan Line.

Search directly for keywords Yuelu Lake

That the lake was pierced by a rocky slope.

Open Satellite map: through the stone Lake

He should be on the right side of the left, because only the right side has a pavilion.

Combined with its EXIF information: December 4 o'clock in the afternoon 03, this time the sun should be west.

Combined with satellite map: The Sun should be on the left side of the picture and West, not the right or the east.

And the clouds in this picture show the sun is in the east.

Logical contradiction, so is P's.

Combined with these two points, it can be judged that this is a high imitation of the map.