Photos without focus. Focus with focus: methods of control of depth of field in photographs. A brief overview of programs to increase sharpness

It's no secret that now, to make a photo on the usual, so say, "soap", you need to press a little button, after that the lens focuses on the object and then, when we already see a clear image in the viewfinder (or on the screen), press the button to End and make a photo. In principle, everything is simple and understandable.

But Lytro decided to change this process. They declare that they will revolutionize the world of photography. With their cameras, you can take a photo without focusing the camera on the object. And you can adjust sharpness already in post-processing. Honestly, when I first saw it, it seemed to me that I was sleeping.



This technology was developed in Stanford University under the leadership of Dr. Ren NG since a long time - it was invested about 50 million dollars. The company showed several photos so that we fully understand what they were invented. So, in the gallery, the link to which below, you need to click the mouse cursor on the desired section of the photo and it is there that the photograph will focus, and everything will become blurred around.

Example:
Focus on the girl

Or on colors

Unfortunately, on Habré you can not insert Flash in the post, so you have to climb on the site and play it there. Come in the gallery and press the pictures on the places where you want to focus.

Publication date:10.10.2015

What if you systematically get fuzzy frames? To blame the technique or the reason for that action? This article will help to figure out. In it, you will learn how to check the accuracy of the device focusing the device and adjust it to obtain sharp frames.

Nikon D810 / Nikon 85mm F / 1.4D AF NIKKOR

I want to immediately say that in most cases the camera is not mistaken, but a person working with her. So, to begin with, it is worthwhile to look for the cause of focusing errors in your own actions with the device. In recent lessons, we told how to work with different autofocus modes and with focus points. These knowledge will help you in practice. It will be useful to familiarize yourself with the article on how the novice photographer evaluate and improve the quality of its own work.

Autofocus can be mistaken and when working with insufficient lighting, and when shooting complex, diverse frames (the camera will not know what to focus on). You can not allow such lablems of focusing by simply configuring the device according to the conditions of shooting. Suppose the choice of a constant focus mode of AF-C and 3D tracking the object when shooting sports will make it possible to get much more sharp frames than working with frame-frame focus. But there are focus errors that occur systematically, regardless of the conditions of shooting.

Beck and front focus

In the mirror chambers, the phase type of autofocus is the main one. It is with him that you have a deal, working through the camera's viewfinder. Phase focus occurs using a separate sensor installed in the chamber. As you can see, this is a complex system, and sometimes it can work inconsistently.

The consequence of this will be systematic autofocus errors, called back and front-focus. In the case of a back-focus, the camera is constantly focused not on a removable object, but for it. In the case of front focus, on the contrary, the camera is constantly focused before the object. Please note about the presence of back and front focus can only be said when the camera is mistaken with focusing every time in the same direction. If one frame turned out sharp, and the other is not, then the problem is to look elsewhere.

Especially terrible, the problem of back and front focus when working with high-tear portrait optics. There, the depth of field will be very small, therefore any, even minor focus errors will be very noticeable in the photo. For example, sharpness in the frame will not be in the eyes of the model, but on the ears.

On the other hand, if you are a happy owner of a whale lens or universal zooms that do not shrink high lights can sleep well. After all, even if your camera has a back or front focus, you will most likely not notice, because focus errors will be compensated by a great depth of field.

Contrast autofocus

In the mirror chamber, in addition to phase focus, there is another type of autofocus - a contrast. You activate it, including Live View mode and booking a picture through the machine screen. With a contrasting autofocus, there can be no back and front focus, as it does not require individual sensors for its operation, the focus runs directly in the matrix. Thus, if the phase focus regularly "smears", try switching to Live View mode and work with contrast autofocus. It works a little slower, but it gives more accurate results.

Checking accuracy focusing

How to check the camera on the back and front focus? Accurate conclusion about the presence or absence of these drawbacks can only be given by the authorized service center of the manufacturer of photographic equipment. However, the photographer can make a preliminary estimate of the focus accuracy.

We offer a simple algorithm for such an inspection.

First prepare the camera.

1. Insert the battery and memory card into the camera. Turn on the camera.

2. Check if autofocus is enabled.

3. Press the MENU button, in the Image Quality Point, select High Quality JPEG. If you can work with RAW, you can use this format.

4. Turn on the mode A (the priority of the diaphragm). If you can work with manual mode m, you can use it. Open the diaphragm of the camera to the maximum value. Everything is simple: the smaller the number indicating the diaphragm, the stronger it is open. In the case of a whale lens, you will most likely have to deal with a diaphragm value near F5.6.

5. Set the minimum value of photosensitivity. This is usually ISO 100 or 200. So test snapshots will be clean, without digital noise.

6. Now - the most important thing! Select the focus mode at one point. In the camera menu, it may be called "single-point AF."

7. The case is for small - download and print on any printer a special target to check the accuracy of focusing.

The targets are of different types, but the proposed option is perhaps the most popular. In principle, you can check the focus, say, along the usual lineup (how it becomes clear further), but it is much more convenient to do this in the target.

Checking autofocus

So, the camera is configured, the test target is printed. It's time to act!

    Camera is best set to tripod. Without a tripod, such a check will be extremely inaccurate and disappointing.

    Provide sufficient lighting for shooting. It is best to remove the day by the window. You can use the flash (both built-in and external).

    Put the target on a flat surface, and the camera is located at an angle of 45 degrees to it at such a distance so that the target occupies a significant frame area.

    Select the central point of autofocus. Focus accurately on targets - on Focus Here's inscriptions (focus here). The fat black line with this inscription should settle in your frame strictly perpendicular to the optical axis of the lens.

    Make a few frames. Do not use serial shooting, after each frame focus again. Remember that after focusing, in no case cannot be moved the camera, change the removal distance. If you deal with a zoom lens, test it on different focal lengths. I note that it is most convenient to test from a focal length in a 50 mm area, you can start with it.

    View the received frames. To better consider them, do it not on the screen of the camera, but on the computer monitor. If on all frames you see a systematic identical focus error, then, most likely, you discovered a backing or front focus. You should not worry about this. It is easily eliminated in the service center. And the owners of advanced cameras (starting with Nikon D7200) can configure focus directly in the camera menu.

Thin setting of autofocus

In an advanced level cameras (starting with Nikon D7200) there is a function of an accurate autofocus adjustment function that will help you get rid of problems with the back and front focus, to accurately configure the focus system. The convenience of the function also is that the device remembers the settings separately for each specific lens. Suppose the error manifests itself with one of your lenses. You can make adjustments for it, and they will not affect work with other lenses. When the lens is installed on the camera, it automatically apply the corresponding correction. Note that the fine configuration of autofocus will only work when focusing via the device's viewfinder (with phase focus). When working through the Live View screen, it is not activated, and there will be no need for a need, because in this case a contrast type of autofocus is applied, excluding problems with back and front-focus.

Let's figure out how the autofocus fine configuration feature works.

Probably, each photographer was heard of the offensive, but the objective words "photo outside the focus" or, quite often see that the snapshot made several moments ago cannot boast due focusing on the object.

There are photographers who deliberately teach the generally accepted rules. For them, getting a photo suitable for the definition of "outside the focus" - an end in itself. In fact, it is easy to get used to this type of creativity, because Creating pictures of this category, to a certain extent, does not cause much difficulty, which cannot be said about their perception and analysis.

We suggest to consider several simple tips and examples of shooting photos "out of focus".

What you need to know about the photos "outside the focus"

  • The picture outside the focus is definitely needs a competent approach to the author's process. The photographer must have a good artistic perception and the ability to represent what eventually it is possible to achieve a frame, obviously, this can be achieved only by practice.
  • Sometimes blur or bokeh make a picture very attractive for the viewer. The lack of focus makes him think, "penetrate the frame", causes a kind of curiosity and desire to learn more about the subject.

I will stop your attention at two points relating to the photo "Out of Focus."

Actually, what to shoot?

  • Always pay attention to various forms, structures, objects that could help you create a beautiful picture.
  • Do not try to fill the frame with a large number of characters. On the other hand, it can even help you create a surreal effect, which is always interesting. Here, as they say, you need to know what you expect from a finite picture.
  • Do not forget that every frame you wish to get should force the viewer to stop your gaze, the snapshot should not remain unnoticed.
  • Continue to play with shooting appliances and constantly practice! And who knows, perhaps you will be able to create your own formula.

How to shoot?

  • You just need to install the lens in manual focus mode, moving it forward / backward.
  • Do not forget to choose the highest diaphragm value available to your lens.
  • It is not necessary that the end snapshot will look just like you see a frame in the viewfinder.
  • Converting photos "outside the focus" in black and white color can not only reveal the entire artistic meaning, conceived by the photographer, but also give it even greater effect.

Therefore, continue to practice, continue to shoot!

Examples of photos

In this lesson, I will show you how you can change the focus in the photo, thereby making a noticeable major details of the photo. As a rule, this effect can be made by a camera. But what if we have already ready before us?

Step number 1. For example, a photo of a Japanese dish was chosen. We open it in the program and begin our lesson:

Step number 2.. Now we need to decide which part of the photo we will do focus. Let it be our dish. Take the tool Elliptical Marquee Tool And create a round selection around a plate, similar to this:

Step number 3.. Go to the menu SELECT -\u003e Modify -\u003e Feather (Selection -\u003e Modification -\u003e Decision or click SHIFT + F6.) Set the value to 50 pixels.

Then select the tool Sharpen Tool., set the strength: 30% and select a soft round brush about 400 pixels. Now spend a brush in the center of our selection several times to give more sharpness to the dish:

Step number 4.. Make the selection inversion, click Ctrl + SHIFT + I. Now apply filter Filter -\u003e Blur -\u003e Gaussian Blur (Filter -\u003e Blur -\u003e Blur in Gauss) with such settings:

Step number 5.. Now you need to make a smooth transition from blur to the center of the plate. Select in the menu SELECT -\u003e INVERSEto invert the selection back, then go to Select -\u003e Modify -\u003e Expand and set the value in 100 pixels.

Step number 6.. We invert allocations again and apply Filter -\u003e Blur -\u003e Gaussian Blur (Filter -\u003e Blur -\u003e Blur over Gauss) with the following settings:

Step number 7.. Now for better perception will add a black and white gradient blur. Click Ctrl + J.to copy the selected area to the new layer and discourage it Image -\u003e Adjustments -\u003e Desaturate (Image -\u003e Correction -\u003e Dispute or Press SHIFT + CTRL + U).

One of the essential problems in many beginners, and quite experienced photographers - achieving the desired sharpness of the obtained images. "Get into sharpness" - it sounds very simple, but in practice this action may be a bit more complicated.

On the one hand, there are many ways to get a photo in focus. What method is best to choose and how to use it to achieve the desired results? Let's look at some of the most common and efficient ways to focus the camera.

Frame autofocus

One of the easiest ways to focus the camera is to use frame autofocus, which in most cases is the default setting and one of the most effective ways to photograph.

In migrant mode, you simply targe the camera to the object and press the shutter button halfway.

It blocks the focus on the object, allowing you to reproduce the image without loss of focus if necessary. This method is called focus and recomposition.

For example, in the image above, if you want the bridge to be in focus, you need to position the central point of autofocus on the bridge and click the shutter button halfway.

Then you comply with a snapshot, as you can see above, and press the shutter button already to the end to take a photo. As a result, you will get an object in focus, even if you reconciled the photo.

This option is good for landscape photos or shooting of fixed objects.

Continuous autofocus

Obviously, there are no perfectly fixed objects, so you need a focusing tool that would allow tracking moving objects, while maintaining them in focus.

In this case, continuous autofocus can help. All you need to do is capture an object using the viewfinder, click the shutter button halfway and trace the object when it moves, while at the same time keeps the shutter button halfway. Thus will continuously adjust the focus (hence and name).

Most entry-level cameras require that you use a central point for continuous autofocus, but if your high-level camera, you can determine which autofocus point is used to track the moving object.

Naturally, this type of focus is best suited for shooting, for example, wildlife or in which you need to quickly configure focus.

Autofocus with face recognition

Not all cameras have autofocus with face recognition, but if it is still available, it is a valuable tool for portrait shooting. It uses algorithms for recognizing figures resembling human faces.

In Live View mode, the focus on the face is visible in the process of work in the form of a frame around the face.

All you need to do is press the shutter button halfway to specify the area on which the focus is needed and then take a picture.

Focus point selection


Regardless of which autofocus mode you use, you must have an active point of autofocus on your object. Otherwise, the object will not be sharp.

As a rule, there are two ways to select an active autofocus point: Select or automatically automatically using the camera. Now most cameras are quite well choosing a suitable point of autofocus in most situations. But still not always perfect.

In situations where time does not matter, for example, in portrait or landscape shooting - try to select the autofocus point. Watch the "User Guide" of your camera, if you do not know how to do it.

However, it should be considered the fact that your lens will be best focused when using the central autofocus point. If you use another point to get the focus, the image may not be sharp enough.

Focusing rear button

Another way to get an image in focus is to use the focusing rear button. Depending on the specific camera, you can have an autofocus button on the rear case panel by clicking on which to the end, you will focus on the object.

This is beneficial for a number of reasons, including because it prevents accidental pressing the shutter button and, therefore, shooting photos before you (or the camera) were ready for this. When shooting moving or multiple objects, focusing rear button also allows you to focus on your main object. In other words, the release of the autofocus button, you do not allow the camera to make a focus on a new object, and you can still take photos with a focus on the main object.

Manual focus


The process of manual focus may differ slightly depending on the specific chamber or lens, but the following steps are in principle standard:

  • find the AF-MF switch on the lens and move it to the MF position
  • rotate the focus ring on the lens until you see that the desired object is
  • using the Live View mode, increase the object zoom to check its sharpness. If necessary, adjust with the focus ring.

That's all!

Manual focus can take a little longer than automatic, but it works better in a variety of situations, for example, in macro shot, when you shoot through something (say, using a plant in the foreground to turn the object in the background), objects In places with a pile of people (street scenes), as well as in low light situations. In other words, in situations where automatic focus "resists", do not be afraid to switch to manual.

Hyperfocal Distance


A more complex and technical method for producing focus is to calculate the hyperfocal distance. In principle, it lies in the fact that you must use the calculations of the depth of field for the lens that you use to find the nearest point in the picture where you can still get an acceptable sharpness.

Finding this point will focus on the place that will give the best depth of field and maximizes the area of \u200b\u200bfield into photography.

There are several ways to determine the hyperfocal distance, but the most simple among them are the following:

  • focus on one third of the bottom of the frame. Since the depth of the sharpness extends about two times higher than the focal point, focusing on this third will help you maximize the depth of field;
  • you can use the application for smartphones, such as HyperFocal Pro for Android (shown above) or Digital DOF for iOS devices that will get rid of you from the need to make any mathematical calculations.

If you are a landscape photographer, the use of the hyperfocal distance will be especially useful for you.

Focal Focus Stacking


The final method, which we consider in this article, getting the perfect focus on photos is the use of the Focus stacking method, which is achieved upon subsequent processing.

In fact, you take several different photos, each with its point focusing (that is, with a focus in the foreground, middle and rear) and combine them together in one image upon subsequent processing. The resulting team photo will be sharp from the foreground to the rear.

This method is especially useful for macro shot and shooting still life, as well as good to use for landscape photography.

Caution As for the Focus Stacking method: There can be no movement in the picture.

This is explained by the fact that you are removing several exposures at different times, so if something in the frame is in motion (for example, a tree from behind the wind), it will cause halyols. Everything that moves in the photo will be blurred.

Another difficulty using this method is that you need to configure the focus for each snapshot, without disturbing the position of the camera. Otherwise, the cadres used will not be perfectly combined in post-processing.

So, now you have a number of methods that will help to configure the focus on the objects removable. For their development it will take time. However, this is exactly worth it. Act!