When is manual focus used in digital image shooting?

In fact, the landlord can use manual focus at any time, which can cultivate his own sense of lens.

Usually there are two situations where manual focus is required.

1.The lens is not in focus.

If the subject is not clear in the field of view, focus errors occur.

When shooting through glass or through a screen window (usually against the glass or screen) against a mirror or sleeping, the camera usually focuses on the image in the mirror, not the mirror itself.

Smoke or water splashes are generally not exposed to smoke or water.

In a dark environment.

2.It's too late to focus.

By the time the camera is focused, the subject is long gone.

You can first determine the focal plane, focus well, and wait for the subject to enter (running, racing, westfalling).

The moment of entry into the water).

I hope what I said is helpful to the landlord.

Professional photographers use manual focusing, beginners can use automatic first, and then change to manual when you shoot more and know what aperture produces what effect.

There are several situations in which the camera will have difficulty autofocusing, which can be focused manually:

1.Photograph very bright objects, such as mirrors.

2.Photograph the scenery outside the window through the glass.

3.Photograph objects with weak reflections, such as hair or fur.

4.Disembodied objects, e.g. smoke.

5.Objects that are too dark.

6.Fast-moving objects.

7.The subject is the same or close to the background color, such as a person wearing white clothes standing in front of a white wall.

It is the same as the principle of optical focusing: the reciprocal sum of the eye distance and the object distance is equal to the reciprocal of the focal length, which is a way to directly receive and analyze the reflection from the scene itself, and use the principle of phase difference to carry out autofocus.

There are two types of autofocus:

1. Active: The infrared generator and ultrasonic generator on the camera emit infrared light or ultrasonic waves to the subject. The receiver on the camera receives the reflected infrared light or ultrasonic waves for focusing, and its optical principle is similar to that of triangulation focusing method.

There is also the energy method in the active type, which is used for autofocus in low-end general cameras, and is widely used in various head-up view cameras. Active focus on the bevel, smooth and difficult to focus. Difficult to focus on subjects with high brightness and long distances.

This is due to the fact that the emitted light is reflected in other directions, or does not reach the subject. Since the active camera actively emits light or waves, it can focus in low contrast and low light. The disadvantage is that it is difficult to focus when the subject can absorb light or waves, and it is also reflected by the glass, so it is difficult to focus through the glass.

2. Passive: that is, the way of directly receiving and analyzing the reflection from the scene itself and carrying out automatic focus. The advantages of this autofocus method are; It does not need to launch the system itself, so it consumes less energy and is conducive to miniaturization.

Autofocus is ideal for subjects with a certain brightness, good for backlit conditions, and autofocus for objects with high brightness at a distance. It can focus through glass, but the disadvantage is that it is difficult to autofocus on subjects with thin lines. Difficult to focus in low contrast, low light, poor autofocus on moving objects, poor autofocus on polarized subjects, and poor focusing on black objects or mirrors.

In fact, it is the imaging principle of convex lens 1 u+1 v=1 f, where u is the object distance, the distance from the lens to the subject; v is the distance from the lens to the image sensor; f is the focal length of the lens.

It is the same as the principle of optical focusing: the reciprocal sum of the eye distance and the object distance is equal to the reciprocal of the focal length, but it is generally a combination of a group of concave lenses, convex lenses and flat mirrors, so the specific calculation is not easy.

The differences are:1The imaging medium is CMOS or CCD, not film.

2.The pixels are dot matrix, not like the film is continuous, there is a bit limit, not as good as the saturation of the film, but the human eye is now imperceptible.

3.Because it is a dot matrix digital, post-processing is much more convenient, and it is easier to realize controls such as autofocus.

It is the principle of optical focusing imaging.

The long can only sleep, and when shooting, I ran to the main entrance school for a debugging certificate, which should be able to do some things, otherwise there should be no way, so this little pig wants to buy ** No way.

This thing can't be adjusted at all when it autofocuses, or you need to consider your feel when you switch to manual adjustment.

Focus on his shooting peppers, pickled peppers we can still adjust, this can bring you a better choice, okay, my money now.

How do I adjust the out-of-focus when shooting with autofocus? That means there is a problem with your settings, and you should choose a focal length to choose a fixed one, and he won't run anymore.

When the camera autofocuses on shooting, you stop for a while, and it will resume focusing.

When the camera is autofocusing, I'm just setting it to all auto.

This is your camera is not very powerful and can not capture moving objects.

The camera autofocus is pickled pepper, you can reset it to see the situation.

I just checked it for you, and you can adjust the angle in the settings.

For this, you need to adjust the corresponding parameters in the settings according to the situation at the time.

How to adjust the kickline when the camera is shooting autofocus, and you can adjust it directly in the settings?

The camera's autofocus is how to adjust the focus when shooting, and you have to ask those professionals who take pictures.

If the camera is out of focus during the automatic cancellation process, this can be directly adjusted manually.

There are probably the following to learn::

1. First of all, you have to look at the manual, how the AF point of your camera is distributed - some are widely distributed in the whole frame, and some are relatively in the middle of the picture, usually the viewfinder can be seen with dynamic bright spot distribution;

2. According to where you want the subject to be framed in the frame, whether there is a focus point coverage at that position, if so, and distributed in the middle of the relatively middle, the focus can be correct;

3. Although some subjects are in the coverage area of focus, but they are already at the edge of the focus area, special attention should be paid to whether the camera has selected that position for focusing, if not, then align the position in the middle of the viewfinder to the subject after the ranging focus is correct, then press the "AF lock" and then recompose the shot, and then press the shutter to release the "AF lock";

4. For the subject that is not in the AF point coverage at the beginning, repeat the method, first use the viewfinder** (i.e., the picture**) to measure the focus, press the AF lock, reframe the shot, and then press the shutter;

5. For macro shooting or special objects (such as small contrast with the background, etc.), it is better to use manual focusing, which is more reliable;

6. For those with large depth of field requirements, the method of large circle and ultrafocal length can be used to focus first;

7. For fast-moving objects, use the manual focusing method.

You're using a green-framed fully automatic transmission.

It's a problem you set up.

The camera's auto-metering thinks that the environment is dark, so it will automatically adjust the shutter speed, that is, slow down the shutter to make the light entering the camera brighter, so when you press the shutter, the shot will be false because you are not steady.

When you turn on the flash, it can only give more light when you press the shutter, but when the camera is metering, that is, when you press the shutter halfway, the flash does not give any auxiliary effect on the metering.

You can choose to use a manual transmission, make the aperture wider to make more light through, slightly faster shutter speed to make up for your unstable end, or set ISO (sensitivity) to increase the point to make the camera more sensitive to low light, but this will affect the noise that will appear.

If the end is unstable, you can consider relying on the wall or other supports, and if not, go on a tripod. Stabilization.

Usually when I work, I use anti-shake and basically rely on the elbow. Hehe. They were all practiced with bricks in the past.

A tripod is an important tool in photography, and it can stabilize in many situations, so that you can shoot clear images. Home machines are generally hand-held digital camcorders, and the stability performance cannot be compared with shoulder-mounted digital camcorders, which will cause the picture to shake due to the unstable handheld, especially in the case of dim light and night scenes, the role of the tripod is more obvious.

If you want to make the digital video camera shoot better results and stable pictures at night, it is very necessary to have a tripod, especially when using optical zoom shooting, you can feel very obvious shaking, especially for home digital camcorders, when shooting large zoom at night, even if the electronic stabilizer is turned on, the handheld effect is still not as good as the tripod. At present, there are many tripods on the market, ranging from tens to thousands, we had better choose one with a three-way gimbal, so that you can make fine adjustments when composing, such as the Medas pt26N tripod, of course, if your funds are not abundant, the domestic Weifeng 330A aluminum alloy tripod is an economical high-quality tripod, it has a three-dimensional gimbal, the actual use effect is still good, suitable for shooting night scenes.

Autofocus is a very practical function of digital video cameras, suitable for beginner photographers, but many home digital cameras will have autofocus can not work properly when shooting night scenes, resulting in blurred night scenes, at this time you can switch to manual focus, use the LCD screen to view the effect of focusing, in order to choose the right focal length, so that you can make your night scene subject clearer, get more accurate shooting effect than autofocus.

Many friends may rarely use the manual focus function, here is a simple way to press the "focus button (focus)", then you can see the appearance of the "hand" on the LCD screen, indicating that you can focus manually, then press the zoom switch, so that the DV is in the state of telephoto (W), because after the image is adjusted in the telephoto state, the image can be guaranteed to be clear in other focal length states; Then aim at the subject so that it is in the middle of the frame, adjust the sharpness to the best, then use the lock function to lock the focus in a fixed position, then recompose the shot, return to the original position, and adjust the two focus buttons respectively to make the subject clear.