Typical technical mistakes easily made during shooting

Most beginners will make the same mistake when they are new to photography. Before their understanding and application of camera technology reach the level of perfection, there will always be some photos that fall victim to the following mistakes. Even after the entry stage, the photographer will make mistakes from time to time in the later shooting.

First of all, let’s say that the “error” we mentioned in this section is based on the recognition that photography aims to capture images with correct and clear exposure. However, this does not mean that we cannot take distinctive photos. They may go against our universally recognized photography purpose in an artistic and pioneering way. Generally, we should master some photography skills before innovation.

1、 Overexposure

If white areas with no details appear in your photo, it means the photo is overexposed. In other words, the amount of light the sensor obtains is much more than the amount of light 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, you can reduce the aperture, shutter speed and ISO value

Consider other factors.

The overexposed area in the image can also be slightly darkened through targeted post-processing, so that some details can be seen again. The overexposure area should be distinguished from the brighter image area, because the latter may only look pure white, but it actually has details. This difference can be seen through the histogram on the camera screen during shooting. If the image area is engulfed by white, the right side of the histogram will be truncated.

If the image is highly overexposed, the bright image area will be engulfed by white. That is to say, no details can be seen in that area, only pure white. This usually happens when you have metering errors or manual settings errors.

2、 Underexposure

Too little light reaching the sensor will lead to insufficient exposure. The reason for this is also that there is a problem with the combination of aperture, shutter speed and ISO value. The final result is that a pure black area without details is formed in the image. What’s worse, because the amount of light is too little, the underexposed area will form interference noise.

However, when it is uncertain how to do better, it is better to underexpose than overexposure, because white “eroded” information is more than black “submerged” information. It is also important not to confuse overexposure and underexposure with high key shooting and low-key shooting. Although areas of light and dark tones may also appear in high key and low-key images, there are details in these areas.

When the exposure is insufficient, the amount of light obtained by the sensor is too small, so the charge generated by the light cannot be distinguished from the basic charge of the sensor itself. The result is usually: ugly noise and clear noise appear in the area that should be pure black.

3、 Focus error

The clear area in the image is not in the expected focus position, which may be due to the photographer’s inattention or unstable hands during shooting. If you adjust the viewfinder area after focusing and move the camera slightly forward or backward at the same time, the set focal plane will be moved to the front or rear of the focusing main body.

To prevent this problem, it is recommended that you use the auto focus mode with a selectable focus area and select a focus area close to the point you want to focus on. In addition, increasing the depth of field can also help solve this problem, that is, reducing the focal length or aperture for shooting. If it still doesn’t work, check the camera’s autofocus mode to see if it is calibrated incorrectly.

It is important that the focus is in the right place, especially in portrait photography. A model whose eyes are not in the focal plane is usually considered to be out of focus.

4、 Dithering

If shaking occurs during shooting, a “ghost picture” will be formed, that is, the subject appears faintly on the image many times and is not clear. 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 hold the camera to shoot 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 is 1/150 s. There is no problem if the shutter speed is slightly shorter. However, if the shutter speed is longer than this value, you need to use a tripod or an optical anti shake system to capture an image without jitter. If you choose to use a tripod, make sure the camera does not shake when you press the shutter release key. In addition, you can also use the automatic shutter function of the camera or the shutter remote control.

When the shutter speed is relatively long, moving will cause the picture to become a blurred and jittery “ghost picture” – no matter the subject moves, the camera moves, or the photographer moves.

5、 The contrast is too high

The contrast range of some shooting scenes is so large that the sensor cannot fully display them. The result is that some areas of the image will be overexposed or underexposed. In order to deal with this kind of scene, you can measure the brightness of different parts of the subject to obtain its contrast range, and then select a moderate exposure to minimize the overexposed or underexposed image areas. Later, you can brighten dark areas or deepen light areas in post processing.

You can also use HDR technology to take a series of photos with different exposures, and then combine them together, so that the contrast range of the subject can be fully displayed without loss of image details. As for the extent to which you want to apply this technology, of course, it is up to you to decide. Combining 2 to 3 images will greatly reduce the contrast of the image, and will not make the final image look too unnatural.

When shooting indoors, it is easy to produce large brightness contrast. If there is no additional light source, reflector or HDR technology, you must give up some image information.

6、 Improper use of flash

If you use the built-in flash of the camera to shoot in a dark room due to insufficient light, there will be two problems: red eye; The amount of light behind the subject suddenly decreases, or even the rear part of the subject is under exposed while the front part is over exposed.

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

When using a flash, the light it emits is extremely uneven. This is because the flash is 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 through composition: the elements to be photographed must be on the image plane parallel to the sensor plane, so that the overexposed elements in the foreground and the underexposed background elements can be avoided. When shooting, you can get closer to the subject to make the viewfinder area smaller, and use the flash lamp as a supplementary light source instead of the main light source.

Another way to avoid flash problems when shooting in a dark room is to use a camera with low noise when the ISO value is high.

In many snap photos taken with the built-in flash, we can see uncomfortable red eyes. This is just one of the technical difficulties in shooting with flash. There are also many photography obstacles hidden in using flash. You should always practice using flash.

7、 Backlight

Backlight photography is prone to errors. The strong brightness contrast between the illuminated background and the dark subject that is not illuminated by the light is an important factor causing errors. In order to correctly measure the brightness of the subject, you need to use spot metering or local metering to measure light during shooting, and then select the corresponding exposure value to make the subject correctly exposed — in this case, you must accept that the background will be slightly overexposed. Another feasible approach is to lighten the foreground only 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 to avoid the interference of reflected light and the light directly hitting the lens to produce light bands. Therefore, you must use a light shield when shooting.

When shooting against light, metering is usually not so simple. However, the transparent subject will appear particularly bright under backlight conditions.

8、 Background confusion

As long as you are not shooting in the studio, whether in the field or in the room, it is difficult to show the main subject as the most important image element. You can easily take a picture that has a lot of details in the background that can distract the viewer. If there is no clear proportion distribution of image elements, the image will appear very confused, do not know what to express, and give a very noisy feeling. In order to avoid such image effects, not only in composition, but also in technology, we should pay attention to several points: select a main shooting object, and then arrange it as a dominant element in a scene. In other words, you should choose a relatively small viewfinder area – either close to the subject as much as possible, or “extract” the main 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 site is also very important for the harmony of images – looking for a harmonious plane as the background to shoot.

Avoid color and eye-catching objects in the image; If so, you can change the angle of view when shooting. In addition, the depth of field should be appropriate – the clearer the surrounding environment, the more important it will be. In turn, you can use the blurring effect to reduce the importance of the environment. Choosing a large aperture aperture and/or a long focal length can result in a smaller depth of field. Another method can bring a clear sense of harmony to the image, which 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 photos.

We can decide what is in the image by selecting the focal length, angle of view, and distance from the subject. Make good use of the viewfinder, and carefully see which areas need to appear in the image and which can be cut or faded before shooting.

9、 White sky

When you select the sky as the background of the subject, the sky is often brighter than the subject itself. Therefore, in the final image, the sky may not be the blue sky and white clouds you see, but only a very bright area, or even a pure white area. This phenomenon is related to the strong light and dark contrast between the subject and the sky, which determines that only one of the two image areas can be correctly exposed. To solve this problem, you can select an intermediate exposure value, and then process the dark color area and light color area respectively on the computer, or take two images with different exposures, and then combine them into an image with a larger dynamic range on the computer.

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

10、 Too close to the subject

If you want to hold the camera close to the subject, you will be limited by the minimum focusing distance of the lens: if the focusing distance is less than this distance, the final image will be blurred. Therefore, you should choose the macro lens or the macro function of the lens to shoot. When using the auto focus mode, you should ensure that you reach the precise sharpness before releasing the shutter, so that you will not inadvertently exceed the minimum focusing distance of the lens when focusing. In addition, using a smaller focal length can reduce the minimum focusing distance, which in principle can be closer to the subject. When you use a zoom lens, it is very important that the minimum focusing distance marked on the lens is always the minimum focusing distance with the smallest focus. The last method is to shoot a little farther from the subject, and then make the desired image area larger by cropping.

Each lens has a minimum distance at which it can focus clearly. Subjects that are too close to the camera will only be blurry.

The above are typical technical mistakes that are easy to make when shooting. The new year has come. Please correct these low-level mistakes quickly!