What are the technical mistakes that are easy to make when shooting?

To improve the level of photography, we should not only learn photography knowledge and make various attempts, but also understand what not to do and the problems existing in our own photos. As a beginner in photography, I often make mistakes, but the most important thing is to learn from them, so that I can make progress! Today, I would like to recommend some technical mistakes that are easy to make when shooting, hoping to help you ~

What are the technical mistakes that are easy to make when shooting? First, overexposure.

If there are white areas with no details in your photos, it means that the photos are overexposed. In other words, the amount of light obtained by the sensor is much more than that required for correct exposure. The reason why this happens is usually because there is a problem with the combination of ISO value, aperture and shutter speed, and of course it is also related to the brightness of the shooting scene. In principle, in order to make the sensor receive less light, the aperture can be reduced, the shutter speed can be shortened, and the ISO value can be reduced. However, before such adjustment, it is necessary to

Consider other factors.

The overexposed areas in the image can also be slightly darkened through targeted post-processing to make some details visible again. Here, we should distinguish between overexposed areas and bright image areas, because the latter may only look pure white, but in fact there are details. This difference can be seen by the histogram on the camera display screen when shooting. If the image area is swallowed by white, the right side of the histogram will be truncated.

If the image is overexposed, bright image areas will be swallowed up by white. In other words, there is no detail in that area, only pure white. Usually, this will happen when you have a measurement error or a manual setting error.

Second, underexposure.

Too little light reaching the sensor will lead to underexposure, which is also due to the comprehensive effect of aperture, shutter speed and ISO value. As a result, a pure black area with no details is formed in the image. To make matters worse, because there is too little light, the underexposed areas will form interference noise.

However, under-exposure is better than over-exposure when we are not sure how to do it better, because white "erodes" more information than black "drowns". It is also important not to confuse overexposure and underexposure with high-profile shooting and low-key shooting. Although high-profile and low-key images will also have areas dominated by light and dark tones, these areas still have details.

When the exposure is insufficient, the sensor gets too little light, so the charge generated by the light cannot be distinguished from the elementary charge of the sensor itself. The result is usually: unsightly noise and clear noise appear in the area that should be pure black.

Third, focusing error.

The clear area in the image is not in the expected focus position, which may be due to the photographer's inattention or too unstable hands when shooting. If the viewing area is adjusted after focusing and the camera moves forward or backward slightly, the set focal plane will move to the front or back of the focused object.

In order to prevent this problem, it is recommended that you use the autofocus mode where you can select the focus area, and select the focus area close to the point you want to focus on. In addition, increasing the depth of field also helps to solve this problem, that is, reducing the focal length or aperture of shooting. If it still doesn't work, check the autofocus mode of the camera to see if it is calibrated incorrectly.

It is very important to focus on the right position, especially in portrait photography. The model's eyes are not in the focal plane, which is usually considered as a focus error.

Fourth, jitter.

If there is jitter when shooting, it will form a "ghost map", that is, the subject appears blurred on the image many times. The reason for this problem is that the exposure time is too long: when the shutter is opened and the light shines on the sensor, the camera or the subject moves. When the shutter speed is what, the photographer can still take an image without jitter, depending on the focal length used for shooting: the longest shutter speed without jitter is the reciprocal of the focal length (multiplied by the current frame coefficient).

For example, when the focal length is 150 mm, the longest shutter speed is1150 s, and it is no problem to shorten the shutter speed. However, if the shutter speed is longer than this value, you need to use a tripod or an optical anti-shake system to take a jitter-free image. If you choose to use a tripod, make sure that the camera does not shake when you press the shutter button. In addition, you can also use the camera's automatic shutter function or shutter remote control.

When the shutter speed is very long, the movement will make the photo become a blurred "ghost"-whether the subject moves, the camera moves or the photographer moves.

Fifth, the contrast is too high.

The contrast range of some shooting scenes is too large for the sensor to fully display. As a result, some areas in the image will be overexposed or underexposed. In order to cope with this scene, you can get the contrast range by measuring the brightness of different parts of the subject, then choose a moderate exposure to minimize the overexposed or underexposed image areas, and then you can brighten the dark areas or deepen the bright areas in the post-processing.

You can also use HDR technology to take a series of photos with different exposures, and then combine them together, which can fully show the contrast range of the subject without losing image details. As for the extent to which you want to apply this technology, it's up to you. Combining two or three images together will greatly reduce the contrast of the images and will not make the final image look too unnatural.

When shooting indoors, it is easy to produce a large brightness contrast. If there is no additional light source, mirror or HDR technology, some image information must be given up.

Six, improper use of flash

If you shoot in a darkroom with the built-in flash of the camera because of insufficient light, there will be two problems: red eye; The amount of light behind the subject drops sharply, even the back of the subject is underexposed and the front is overexposed.

Red-eye is caused by the improper angle of light from the built-in flash of the camera entering people's eyes. The easiest way to avoid red eye is to use an external plug-in flash. In this way, the light source is much higher than the sensor plane, which changes the incident angle of the flash accordingly. You can also use a bright plane to reflect the flash, thus avoiding direct flash.

When a flash lamp is used, its light distribution is extremely uneven. This is because the flash forms plane illumination, and the light will decrease sharply with the increase of distance. In order to make this effect less obvious in the image, it can only be adjusted by composition: all the elements to be photographed should be on the image plane parallel to the sensor plane, so as to avoid overexposed elements in the foreground and underexposed elements in the background. When shooting, you can get close to the subject to make the visible area smaller, and use the flash as the auxiliary light source instead of the main light source.

Another way to avoid the flash problem in darkroom shooting is to use a camera with less noise when the ISO value is high.

In many snapshot photos taken with built-in flash, we can see uncomfortable red eyes. This is just one of the technical problems encountered in shooting with flash. There are many photographic obstacles hidden in the use of flash, so you should practice using flash frequently.

Seven, backlight

Backlight photography is easy to make mistakes. The strong brightness contrast between the illuminated background and the dark object that is not illuminated by light is an important factor leading to the error. In order to measure the brightness of the subject correctly, you should use spot metering or partial metering before shooting, and then choose the corresponding exposure value to expose the subject correctly ―― in this case, you must accept that the background will be slightly overexposed. There is another feasible way: only brighten the foreground to reduce the contrast of the image. In addition, it should be noted that the light should be completely blocked by the subject, so as not to interfere with the reflected light and the light directly entering the lens to produce light bands. So be sure to use a hood when shooting.

When shooting against the light, metering is usually not that simple. Transparent subjects will be particularly bright under backlight conditions.

Eight, the background confusion

As long as it is not shot in the studio, it is difficult to show the subject as the most important image element, whether in the field or indoors. It is easy for you to take such a photo: there are many details in the background that will distract the viewer's attention. If there is no clear proportion distribution of image elements, then the image will appear very chaotic, and I don't know what to express, giving people a very noisy feeling. In order to avoid this image effect, not only in composition, but also in technology, we should pay attention to several points: choose a subject and arrange it in a scene as the leading element. In other words, you should choose a relatively small viewing area-either as close as possible to the subject, or "extract" the subject from the surrounding environment with the help of a telephoto lens, and use the optical characteristics of the lens to achieve your goal. The choice of shooting location is also very important to the harmony of the picture ―― finding a harmonious plane as the background for shooting.

Avoid colorful and eye-catching things in the image; If so, you can change your perspective when shooting. In addition, the depth of field should be just right ―― the clearer the surrounding environment, the more important it is. Instead, you can use fuzzy effects to reduce the importance of the environment. Choosing a large aperture and/or a long focal length can form a smaller depth of field. Another way to bring a clear sense of harmony to the image is to convert the image into a black-and-white image afterwards, thus highlighting the shape of the subject. In this way, the confusion caused by different colors disappears in the photo.

By choosing the focal length, viewing angle and distance from the subject, we can decide what is in the image. Make good use of the viewfinder and observe carefully before shooting to see which areas must appear in the image and which can be cut out or faded out.

Nine, the white sky

When you choose the sky as the background of the subject, the sky is often brighter than the subject itself. So in the final image, the sky may not be the blue sky and white clouds that your eyes see, but just a very bright area, even a pure white area. This phenomenon is related to the strong contrast between the subject and the sky, which determines that only one of these two image areas can be exposed correctly. To solve this problem, we can choose a middle exposure value, and then process the dark area and bright area separately on the computer, or take two images with different exposures, and then synthesize an image with a larger dynamic range on the computer.

Growing photographers often wonder how the dark gray sky actually looks white in photos. The reason is that the brightness contrast between the sky and the ground is too large, and the automatic exposure mode is used when shooting-only the light at the lower part of the image is measured.

Ten, too close to the main body.

If you want to put the camera close to the subject, you will be limited by the minimum focal length of the lens: if the focal length is less than this distance, the final image will be blurred. So you have to choose the macro lens or the macro function of the lens to shoot. When you use autofocus mode, you should ensure the accuracy of sharpness before releasing the shutter, so that you will not inadvertently exceed the minimum focal length of the lens when focusing. In addition, using a smaller focal length can reduce the minimum focusing distance, and in principle, it can be closer to the subject. When using a zoom lens, it is very important that the minimum focal length marked on the lens is always the minimum focal length of the minimum focal length. The last method is to shoot at a distance from the subject, and then enlarge the desired image area by cropping.

Each lens has a minimum distance to focus clearly. Subjects that are too close to the camera will only blur.

The above are typical technical mistakes that are easy to make when shooting. The new year has come, so hurry up and correct these low-level mistakes!